Getting Scientific with Brake Fluid Log Out | Topics | Search
Moderators | Register | Edit Profile

Australian RR Forums » Silver Shadow Series » Getting Scientific with Brake Fluid « Previous Next »

Author Message
Top of pagePrevious messageNext messageBottom of page Link to this message

David Lacey
Experienced User
Username: dlacey

Post Number: 34
Registered: 11-2010
Posted on Saturday, 24 January, 2015 - 10:41 am:   Edit PostDelete PostView Post/Check IP

All,
In other threads we discuss RR363 drying-up and the 'anecdotal' success with castor oil recipes as a substitute. To convince the majority that these substitutes are 'safe' we need more scientific data. No big company is gonna risk making statements on suitability of any fluid due to liability concerns of their legal people.

So, how about setting-up our own measurements? I have contacted a local university here (thru http://mytribos.org/)about making tribological measurements on some brake fluid samples using a four-ball tribo tester like this:
http://www.falex.com/pdf/FalexFourBallEP.pdf

I am sure we could establish relative lubricating properties of fluids versus RR363.
The relevant standard appears to be http://standards.sae.org/j1703_201408/
but the tests for wear and lubrication therein are based upon 24000 cycles of a test hydraulic cylinder...this is quite a different situation to our metal-on-metal hydraulic pumps.

I propose a test condition (please hilite any other parameters):
sliding motion
1760 cycles per minute
100 Celcius
500Kg load


I propose test liquids:
DOT3
RR363
DOT3 +5% Castor
DOT3+10% Castor
DOT3+10% PAG100 AC compressor oil
DOT5.1


Once lubricity is settled we can evaluate other parameters such as noise etc with confidence that the pumps won't seize.}
Top of pagePrevious messageNext messageBottom of page Link to this message

Geoff Wootton
Grand Master
Username: dounraey

Post Number: 619
Registered: 5-2012
Posted on Saturday, 24 January, 2015 - 11:50 am:   Edit PostDelete PostView Post/Check IP

Hi David

Great idea, but I can't help wondering about the charges the University would want to make for this research.

If this goes ahead, what are your thoughts on including Shell Brake Fluid DOT 4 ESL as a test liquid, which you mentioned on another thread.

Geoff
Top of pagePrevious messageNext messageBottom of page Link to this message

David Lacey
Experienced User
Username: dlacey

Post Number: 35
Registered: 11-2010
Posted on Saturday, 24 January, 2015 - 12:15 pm:   Edit PostDelete PostView Post/Check IP

Hi Geoff,

Yes, good point on Dot4ESL vs DOT5.1 ... I'm trying to keep the number of samples manageable... my thoughts went something like: DOT4ESL is modified to suit the needs of ABS systems with their fast cycling of the brake pressure....I assume DOT5.1 also meets this requirement since the market for brake fluid is dominated by the new,ABS equipped, vehicles.

The thoughts of this community on the candidates is key...i don't wanna do this twice!

Concerning the costs...well, I am the owner of a Rolls Royce...
Actually I'm trying to suggest its a topic for a student project where I can contribute as 'industrial supervisor' and cover consumable costs, avoiding 'consultancy' rates.
Top of pagePrevious messageNext messageBottom of page Link to this message

Geoff Wootton
Grand Master
Username: dounraey

Post Number: 620
Registered: 5-2012
Posted on Saturday, 24 January, 2015 - 03:09 pm:   Edit PostDelete PostView Post/Check IP

Hi David

It occurs to me the test equipment does not have to precisely simulate the action of the RR hydraulic pump as what is proposed is a comparative study of the lubricity of the various test samples. I mention this as to a large extent the project would be dependent on what equipment the University Department had. It would certainly be a great subject for an Undergraduate Dissertation in Materials Science or Mechanical Engineering. I know at the University of Birmingham in England students are asked to submit their own ideas for projects which are then submitted to a review or ethics committee. This project would not be a big ask.

Regards the test liquids, would it not be better to have DOT3+10% (YAK363) and DOT3+15% (OMAR363) to reflect current usage.

Geoff
Top of pagePrevious messageNext messageBottom of page Link to this message

Jim Walters
Experienced User
Username: jim_walters

Post Number: 30
Registered: 1-2014
Posted on Sunday, 25 January, 2015 - 07:40 am:   Edit PostDelete PostView Post/Check IP

Making a substitute with PAG oil has already been researched here: http://www.nuancierds.fr/Tribune14.htm
Based on what is written I would test a 20% mix of PAG and DOT3.

Quote" Castor -The oil has an average viscosity of 300 mm≤ / s and the PAG 150 ... 150 mm≤ / s. Therefore needs 2 times more PAG 150 that castor to obtain the required viscosity of about 15 mm≤ / s. So: 10% castor, 20% for the 150 PAG.

-The Discovery and testing of DOT / PAG mix are recent, and lack the hindsight and experience on DS or ID .. (testing still ongoing). But all the calculations and tests give her some point lead on the mixture DOT / castor. Provided find and use the "good" PAG ..."Unquote.

The above extract has been Google translated from the original French so reads a little weird. If one reads the whole article it does give good insight into the subject. Bear in mind this is a Citroen based article but there are references to RR363 in it. There is very interesting comment on the miscibility of Castor oil VS PAG oil in DOT3.

SRE22493 NAC-05370
www.bristolmotors.com
Top of pagePrevious messageNext messageBottom of page Link to this message

David Lacey
Experienced User
Username: dlacey

Post Number: 36
Registered: 11-2010
Posted on Saturday, 31 January, 2015 - 10:26 am:   Edit PostDelete PostView Post/Check IP

All,
Given the feedback I'll concentrate on:

DOT3 (Castrol base for all below)
RR363 (Castrol - if I can get some!)
DOT3 +5% Castor
DOT3+10% Castor
DOT3+20% PAG100 AC compressor oil
DOT4 ESL
Top of pagePrevious messageNext messageBottom of page Link to this message

Jan Forrest
Grand Master
Username: got_one

Post Number: 758
Registered: 1-2008
Posted on Tuesday, 03 February, 2015 - 08:29 pm:   Edit PostDelete PostView Post/Check IP

IIRC one of the contributors on the original Citroen website had some tests done on the viscosity of the various mixes of YAK363 Vs RR363. @ 20C (possibly other temperatures) the 10% mix was virtually identical to the pukka stuff. Due to the costs he stopped at that, but it was a long time ago and he may have had further tests carried out.
Top of pagePrevious messageNext messageBottom of page Link to this message

Jim Walters
Experienced User
Username: jim_walters

Post Number: 31
Registered: 1-2014
Posted on Wednesday, 04 February, 2015 - 05:03 am:   Edit PostDelete PostView Post/Check IP

That viscosity test was at this Citroen website:
http://citroen.cappyfabrics.com/tony.html

The author determined that a 9.25% mix of castor oil to Dot3 had the same viscosity as RR363. That is the mix I have been using. Easy to mix accurately, 92.5ml RC aircraft castor oil to 907.5ml Dot3 = 1 litre of substitute mix.

SRE22493 NAC-05370
www.bristolmotors.com
Top of pagePrevious messageNext messageBottom of page Link to this message

Chris Miller
Grand Master
Username: cjm51213

Post Number: 329
Registered: 5-2013
Posted on Wednesday, 04 February, 2015 - 05:37 am:   Edit PostDelete PostView Post/Check IP

A correct analysis must include viscosity at more than zero hours of use. Fluids are subject to sheer, which is sort of like mechanical fatigue and reduces viscosity during use. Viscosity breakdown is why we change oil and this is why we should change brake fluid. Some of the mystery additives in RR 363 are viscosity index improvers, which mitigate sheer and presumably increase fluid life.

So, my question is, how can we measure the loss of viscosity over time due to temperature, pressure, and friction?



After I posted this, I can see that the original post proposed a wear component for the experiment, so my question has already been addressed...
Top of pagePrevious messageNext messageBottom of page Link to this message

Jim Walters
Experienced User
Username: jim_walters

Post Number: 32
Registered: 1-2014
Posted on Wednesday, 04 February, 2015 - 07:09 am:   Edit PostDelete PostView Post/Check IP

For what it's worth, attached is a pic of my 9.25% substitute mix after a week in the freezer. This was mixed up about four years ago, and has sat on a shelf in my shop ever since. A week ago I thought I would put it in the freezer to see if there was any precipitation or other changes. The pic was taken within 20 seconds of taking it out of the freezer. Still absolutely clear, no separation or cloudiness. I was aware of warnings of low temperature use noted on the Citroen site and thought I would do a fairly uncontrolled experiment to satisfy my curiosity. Like I said, FWIW.



SRE22493 NAC-05370
www.bristolmotors.com
Top of pagePrevious messageNext messageBottom of page Link to this message

David Lacey
Experienced User
Username: dlacey

Post Number: 37
Registered: 11-2010
Posted on Monday, 09 February, 2015 - 04:01 pm:   Edit PostDelete PostView Post/Check IP

All,

For each sample I need 300 ml, for the RR363, which is the most important reference fluid here. I have no supply here in Malaysia.

Can anyone confirm some ex-stock availability that I could purchase online? Or, anybody willing to donate an unadulterated sample (of RR363...)?
Top of pagePrevious messageNext messageBottom of page Link to this message

David Gore
Moderator
Username: david_gore

Post Number: 1538
Registered: 4-2003
Posted on Wednesday, 25 February, 2015 - 03:23 pm:   Edit PostDelete PostView Post/Check IP

Phil Sproston, one of our members who has a professional Rolls-Royce service business in NSW recently sent a Castrol Dealer Information Bulletin for publication in the NSW Branch magazine "L & D" as below:

Castrol

Note this refers to the 1 litre bottles and not larger packs - also note Castrol's statement "We would like to bring to your attention that there is no Castrol equivalent to this product". I assume this also precludes larger bulk containers as well so it looks like we will have to make our own version in future.
Top of pagePrevious messageNext messageBottom of page Link to this message

richard george yeaman
Prolific User
Username: richyrich

Post Number: 259
Registered: 4-2012
Posted on Wednesday, 25 February, 2015 - 08:34 pm:   Edit PostDelete PostView Post/Check IP

Looks like a wakeup call for those of us who are still sitting on the fence about using alternatives to RR363.

Richard.
Top of pagePrevious messageNext messageBottom of page Link to this message

Bob Reynolds
Prolific User
Username: bobreynolds

Post Number: 235
Registered: 8-2012
Posted on Wednesday, 25 February, 2015 - 10:27 pm:   Edit PostDelete PostView Post/Check IP

Castrol are still making it though. Fresh supplies have just been sent out to UK suppliers.

They are just not sending it to Australia, for some reason.

But yes, the writing is probably on the wall.
Top of pagePrevious messageNext messageBottom of page Link to this message

Vladimir Ivanovich Kirillov
Prolific User
Username: soviet

Post Number: 118
Registered: 2-2013
Posted on Thursday, 26 February, 2015 - 12:05 am:   Edit PostDelete PostView Post/Check IP

Nasty but twisted. Typical big company approach. Well, we will just have to start importing it in 205 litre drums from UK or USA.
Top of pagePrevious messageNext messageBottom of page Link to this message

Brian Vogel
Grand Master
Username: guyslp

Post Number: 1224
Registered: 6-2009
Posted on Thursday, 26 February, 2015 - 01:38 am:   Edit PostDelete PostView Post/Check IP

It will be interesting to see just how quickly this trend propagates. I'm well known to have been in "the writing's on the wall" camp for quite a while now. The repeated supply outages for extended periods of time made it very clear that official support was on its way out.

I expect the US market will have the same notice in less than two years, perhaps within one.

Brian
Top of pagePrevious messageNext messageBottom of page Link to this message

Hubert Kelly
Prolific User
Username: h_kelly

Post Number: 168
Registered: 3-2012
Posted on Saturday, 28 February, 2015 - 10:13 pm:   Edit PostDelete PostView Post/Check IP

Has anyone heard f castrol gtlma brake fluid, while watching a YouTube clip from U.S.A., California a guy who specializes in Rolls Royce silver shadow has been using it for over 30 years.
Anyway just putting it out there..
PS he did say it was contraversal within his club members
Top of pagePrevious messageNext messageBottom of page Link to this message

Bob UK
Unregistered guest
Posted From: 94.197.120.221
Posted on Sunday, 01 March, 2015 - 04:16 am:   Edit PostDelete PostView Post/Check IP

I think 8 to 12 % castor oil will be fine. No need to mix the pumps will do that.

Castor oil is known for not getting to thick when cold.
The brakes will feel sluggish coming off if to thick. They would work on runny grease. The brake drag will heat the dot and the pumps will heat the dot.

So all the experiments are for interest only.

I have every confidence in this.

Castrol say they make no suitable fluid that's all. Almost all applications will have an alternative somewhere.

Cuban mix is rum and shower gel.

As long as its slippery and doesn't eat the seals.

The pumps are like diesel jerk pumps which are higher pressure. These run 500k miles on diesel.

The prototype shadow had a modified diesel jerk pump for brake pump.

I think the pumps don't work any where as hard as a jerk pump because once the acv is charged the pump is unloaded. I drive mostly hardly using the brakes, plus the master is helping 21%.

About 1/2 pint of castor in the tank plus dot 3 or 4 is fine wall Mart is fine.

Change every 2 years or even 3 Will be fine.

But it's a quick easy to change and cheap so do every year.

Because moisture will migrate from old dot to New dot just changing tank dot only is fine especially if the pistons are fully retracted. As soon as the pistons move out the New dot will get maybe as far as the piston. A quick squirt from each caliper is fine. And a full flush every ten years Will do.

The tank has a shallow sump because the pipes in the bottom sit proud. The dot moves slow through the tank which lets debris drop out.

Suck sludge out with vacuum.

The dot gets warm which is good.

Not sure but due to efforts of GM to make a sealed for life dot system (1990) which doesn't quite work modern rubber hoses have Teflon liners, so they now last better. So only cracks to worry about even then they probably won't blow. Wipe rubber grease on the hoses and metal swages toilhen hoses lasts for years.

Braided looks good but I like the fatter look of rubber.

Colour coding with heat shrink for extra bling.

Braided are available already coloured but are expensive.

Once fitted maybe 30 years life even for rubber.

I use brass half nuts and nip up to 5ftlbs with wrinkle washer and a dollop of rubber grease. The nuts don't hold the wheels on.

The hoses are a standard size for length and fittings. Lucas and many others make them. Bedford light commercial is a good place to check. My front and rear hoses are GM Bedford CF van body to rear axle flexibles which cost £18 for 4 in 1995. I forgot about the rat trap ones. Until the front brakes dragged. 45 mins to fit.

Keep spheres charged to cushion the pump pulses and the two output to brake valve braids are less likely to fail.

My site glasses and tank were fully cleaned 15 years ago and no sign of sludge. My tank top looks scruffy, so I will do a quick clean out when the top is being zinc plated. Quoted £15 chrome is £35 but polishing makes the metal thinner and then theres the caps.

All easy stuff this. And yak363 makes it no more money than doing a normal car twice.

Happy days.

I trying to dispel the complicated myth and drive up the value of Shadows. I often hear of suggestions of £3000 to overhaul a dodgy system, not necessarily so, stainless pistons are not expensive.

Sticky rams can be smoothed by pumping with grease gun with red rubber grease say 1 Inch extended the rubber grease will find it way to the ride valves and give them a dose. The pumps will completely mix it with dot.

A brake overhaul could be as cheap as £250, with luck. It can't be all broken.
The foot of the brake pump pushrod could be made fatter if the cam is worn.


My local RR specialist told me lots of cars actually need little work to get the brakes acceptable. 15years with little maintenance. Discs last well.
Silver Lady Services alma rd Winton Bournemouth. The owners Mr Druite is RR trained and 45 years solely RR. He think my way that the whole system is tough and reliable. He recharges sphere for £20 and often they are fine with 40 year old diaphragms.
Even wrong fluid he quickly sorts out, new diaphragms usually sorts it. The static o rings often don't leak but he changes them anyway. Caliper seals often hold as well. He had a customer put lhm in a dot system and the car lasted a month before the owner realised. The brakes still worked but the lights flickered. He put in diaphragms and flushed brakes fine and then changed the hoses and seals.

No worry no problem all easy stuff.

(Message approved by david_gore)
Top of pagePrevious messageNext messageBottom of page Link to this message

David Lacey
Experienced User
Username: dlacey

Post Number: 41
Registered: 11-2010
Posted on Tuesday, 03 March, 2015 - 02:04 pm:   Edit PostDelete PostView Post/Check IP

All,
A quick update, I purchased the key materials from UK vendors (will pick them up on a biz trip end Mar). 1 litre of RR363, 500ml PAG100 oil. The castor I have, the other DOTs I can buy here in the jungle.
Top of pagePrevious messageNext messageBottom of page Link to this message

Brian Vogel
Grand Master
Username: guyslp

Post Number: 1228
Registered: 6-2009
Posted on Wednesday, 04 March, 2015 - 12:56 am:   Edit PostDelete PostView Post/Check IP

David,

Just retracing through the thread and I have a question, what is the "ESL" on the DOT 4?

I'm really curious to see if anything that's currently available will work "straight." I have little doubt that brake fluid technology has advanced as brake systems did and that meeting the various DOT specs is just the baseline, with other improvements (possibly lubricity) occurring but not being felt to be marketing-worthy items.

I will be awaiting your results with great anticipation.

Brian
Top of pagePrevious messageNext messageBottom of page Link to this message

Bob UK
Unregistered guest
Posted From: 94.197.120.203
Posted on Wednesday, 04 March, 2015 - 10:06 am:   Edit PostDelete PostView Post/Check IP

Dot 4 is for abs systems and more than one RR guru has suggest straight Dot 4.

The pumps are jerk pumps like diesel which run on diesel oil. They survive well. Dot is a reasonable lubricant on its own.

However a spot of castor oil isn't going hurt the wallet so a toast to YAK 363.

RR363 predates Dot4. Maybe if DOT 4 had been first RR would recommend it.

There are loads of vegetable and nut oils. But dot and castor is going to be the cheapest.

Dot 4 in 5 litre cans is cheap. Replace lid quick and store properly and the dot in the can Will do 1 year of topping up. Plus there is a volume of dot that is displaced by the castor oil. So even cheaper on dot.

One must not get a phobia about one's hydraulics. As stated by my local RR guru the system is tough and robust and providing not to much water gets in it will work fine. But change the dot anyway. A lot of old RRs he works on have not been serviced for years just an odd repair and an oil change. A full service and then the owner does not keep the service up. The cars survive this treatment quite well.
The Achilles heel of the shadow isn't the hydraulics but lack of understanding of what is a simple system. They start by thinking it's complicated, my house plumbing is just as complicated.

In my mind's eye there's a power station. A distribution bit. And pistons moving. All the system does is move pistons, one way only. It doesn't even pull them back. Single acting if you like hydraulics don't get simpler.

(Message approved by david_gore)
Top of pagePrevious messageNext messageBottom of page Link to this message

David Gore
Moderator
Username: david_gore

Post Number: 1546
Registered: 4-2003
Posted on Wednesday, 04 March, 2015 - 04:28 pm:   Edit PostDelete PostView Post/Check IP

Bob,

If DOT4 was a suitable replacement for RR363, Castrol would have deleted RR363 and substituted DOT4 many years ago. Castrol would have also nominated DOT4 as a suitable replacement for RR363 in their recently issued dealer advice relating to deletion of 1 litre RR363 from their product range.

I have personal knowledge of a Club Member's experience with what he called "Maxwell's Silver Hammer" noise from his rear rams after the system fluid was replaced with the notorious "new RR363" a decade or so ago. This is a car that has been meticulously and professionally maintained throughout its ownership and was amongst the first to draw attention to the deficiencies of the "new" formulation and to subsequently return to a more traditional R-R silence after this fluid was replaced with the later revised formulation.

To each his own as they say but I would not be using DOT fluid without the castor oil additive under any circumstances based on this experience..
Top of pagePrevious messageNext messageBottom of page Link to this message

Jan Forrest
Grand Master
Username: got_one

Post Number: 765
Registered: 1-2008
Posted on Wednesday, 04 March, 2015 - 08:18 pm:   Edit PostDelete PostView Post/Check IP

"There are loads of vegetable and nut oils. But dot and castor is going to be the cheapest."

I think you'll find that rapeseed oil is far cheaper than any of the other veg oils. How well it might lubricate I couldn't say, but older diesel engines (excluding Perkins engines) will run happily on it. It's only the more 'modern' DI or common rail ones that won't.
Top of pagePrevious messageNext messageBottom of page Link to this message

Vladimir Ivanovich Kirillov
Prolific User
Username: soviet

Post Number: 120
Registered: 2-2013
Posted on Wednesday, 04 March, 2015 - 11:03 pm:   Edit PostDelete PostView Post/Check IP

I wonder what would happen if a hundred of us turned up at castrols head office with placards etc complaining that Castrol did a deal with rr/b to provide a specialized fluid and then dropped us all in the looney bin by saying they would no longer make it even though they know there are still a lot of our types of cars on the road. Could Castrol be somehow embarrassed by this show of force or would they stonewall us and or decide to put the price of the original fluid up 10 fold. Well being an oil company, you simply could not trust them could you. In the trade, I intend as much as I like Castrol products, to boycott them savagely. I like doing things like this to big companies, it makes me feel good. At the very least they should supply us with the technical information needed to know for certain what type and percentage of lubricant we should add to other brake fluids. Its not as if they sold the original fluid at a loss over the past couple of decades is it?
Top of pagePrevious messageNext messageBottom of page Link to this message

Chris Miller
Grand Master
Username: cjm51213

Post Number: 334
Registered: 5-2013
Posted on Thursday, 05 March, 2015 - 01:28 am:   Edit PostDelete PostView Post/Check IP

Better to apply pressure to get Castrol to release the formulation, rather than try to get them to produce an unprofitable product.
Top of pagePrevious messageNext messageBottom of page Link to this message

Brian Vogel
Grand Master
Username: guyslp

Post Number: 1230
Registered: 6-2009
Posted on Thursday, 05 March, 2015 - 01:31 am:   Edit PostDelete PostView Post/Check IP

It would be interesting to know who did the actual testing (and I'd think that was RR) of RR363 (and whatever other variants were under consideration at the time).

I doubt very much that Castrol has any hard data on how RR363 works in SY series cars. I would presume RR (or, now, Bentley) holds the historical testing data, but I could be wrong.

It would strike me as odd if Castrol were to make any statement about a "suitable substitute" for RR363 if they are not the entity that did the "suitability" testing way back when. I presume they made this stuff to spec, with the spec evolving to get the result RR ultimately wanted.

Brian

P.S. to Vladimir: There are a great many who state that RR363 has always been a money-loser for Castrol due to the incredibly limited market. I can actually believe that since the total production numbers of the cars that need to use it is smaller over the course of 15 model years than the production numbers of many single models common cars in a day. There was a certain marketing cachet that I'm sure was quite desired back in the day by being "the exclusive producer to Rolls-Royce Motorcars."
Top of pagePrevious messageNext messageBottom of page Link to this message

Bob UK
Unregistered guest
Posted From: 94.197.120.255
Posted on Thursday, 05 March, 2015 - 07:22 am:   Edit PostDelete PostView Post/Check IP

Dave,
I think on reflection that your right about DOT 4 and RR approval.

If only DOT is available, can't imagine there being no castor oil, then it won't wreak the pumps.

The rams I suspect may grumble.

I go with yak363. Nice and safe cheap option. Happy days

(Message approved by david_gore)
Top of pagePrevious messageNext messageBottom of page Link to this message

David Gore
Moderator
Username: david_gore

Post Number: 1548
Registered: 4-2003
Posted on Thursday, 05 March, 2015 - 08:10 am:   Edit PostDelete PostView Post/Check IP

P.S. to Vladimir: There are a great many who state that RR363 has always been a money-loser for Castrol due to the incredibly limited market. I can actually believe that since the total production numbers of the cars that need to use it is smaller over the course of 15 model years than the production numbers of many single models common cars in a day. There was a certain marketing cachet that I'm sure was quite desired back in the day by being "the exclusive producer to Rolls-Royce Motorcars." - Brian Vogel

True - the statement that RR363 was not a profitable product for Castrol was made by a senior Castrol Australia Technical Specialist in response to a question from me during a post-presentation Technical Session Q&A at the 2002 RROC[Australia] Federal Rally at Coffs Harbour on the suitability of DOT3/Dot4 fluids for Shadows. He also made the comment that if another Castrol product was equivalent/superior to RR363, Castrol would make the change immediately for financial and reduced stock handling benefits.

I am also aware that DOT3 was originally specified for the first Shadows produced and subsequent problems with the hydraulics necessitated the formulation of a fluid with better lubrication - I do not know what collaboration with Citroen occurred regarding the initial hydraulic fluid selection. Castrol and the RRMC engineers responsible for the Shadow tested a range of alternatives followed by a decision to specify the RR363 formulation for all Shadows. It is relevant to note here, the UK-delivered MPW dropheads and later Corniche vehicles were unofficial long-term test vehicles for problem identification and testing of future enhancements as they could be easily monitored through the RRMC UK dealer network. I would expect Castrol to have held the comprehensive test records with summaries being provided to the RRMC engineers - no doubt these records were most likely junked at some stage during the later changes at Castrol.

It is my personal opinion the RR363 formulation using castor oil probably came about from Castrol's long experience with the use of lubricants containing castor oil in motorcycle racing and aircraft engines.

Note for Jan - rapeseed is OK as a diesel fuel but probably not as an extreme-pressure lubricant. Castor oil has always been the most-widely used lubricant/lubricant additive for high-performance and arduous service racing motorcycle and military aircraft engines from around the WW1 era.
Top of pagePrevious messageNext messageBottom of page Link to this message

Jonas TRACHSEL
Frequent User
Username: jonas_trachsel

Post Number: 61
Registered: 2-2005
Posted on Friday, 06 March, 2015 - 12:35 am:   Edit PostDelete PostView Post/Check IP

I second David's comment on the non-suitability of rapeseed oil as a hydraulic fluid.
When some 25 years ago the first bio-degradeable hydraulic oils, based on ester, appeared on the market, there were some oil companies trying to circumvent the patented formula of the ester-based oils by using vegetable oils such as rapeseed. But these ended in a great disaster, as I know of one particular Caterpillar 40ton crawler that had the hydraulic system completely gummed up, as the vegetable oils cracked up under the operating temperatures in the system and deposited carbonised stuff all over. A very costly repair....
I do not know how hot the hydraulic system in a SY can get under extreme (or even normal) running conditions.
Jonas
Top of pagePrevious messageNext messageBottom of page Link to this message

Bob UK,
Unregistered guest
Posted From: 94.197.120.211
Posted on Friday, 06 March, 2015 - 08:49 am:   Edit PostDelete PostView Post/Check IP

Vegetable and nut oils often go to gum when heated under pressure.
also bacterial mould.

Castrol name is a contraction of castor oil.

WW1 pilots used to get the trots from castor oil flung back by the prop.

Car makers show no signs of moving away from dot so supply of YAK363 dependable for ever.

5.1 , I am not sure about it appears to be a better grade of dot4.
Race guys use dot3/4 because it's never in there long enough to worry about.

The only compliant about dot is paint stripping if a chemist could make dot the doesn't then he would be on to winner.

(Message approved by david_gore)
Top of pagePrevious messageNext messageBottom of page Link to this message

Brian Vogel
Grand Master
Username: guyslp

Post Number: 1236
Registered: 6-2009
Posted on Friday, 06 March, 2015 - 09:51 am:   Edit PostDelete PostView Post/Check IP

Can someone tell me the speed with which DOT fluid "typically" strips paint?

I have tried a number of experiments to try to get DOT3 fluid to remove automotive paint intentionally and cannot seem to get the stuff to do it no matter how hard I try.

Mind you, I'm talking "start dissolving" by application to the painted surface. I've never tried to soak a painted part in DOT3.

The warnings about DOT3 and paint made me absolutely paranoid until I realized that a quick (and by quick I don't mean, "Drop everything this very second to get this stuff off!!") wipe away seems to leave things as they always have been before the splash.

Brian
Top of pagePrevious messageNext messageBottom of page Link to this message

Bob UK
Unregistered guest
Posted From: 94.197.120.94
Posted on Saturday, 07 March, 2015 - 07:51 am:   Edit PostDelete PostView Post/Check IP

When ever using dot have a bucket of soapy water on hand with sponge. The water will instantly wash dot away.

Dot will mess up any paint some paints within a minute, clearcoats are very fast. It will strip cellulose down to bare metal in hours.

Dot cleans Brown stains of carbs, and old dot with a carb soaking overnight works well. Wash in hot water after.

Also if burnt in an engine it can remove carbon.

Powder coatings will eventually crinkle with dot.

There are caliper paints but any dot on the paint should be washed off asap. Because it will crinkle.

I like to wet the paint with soapy water before bleeding. And always give the caliper a good water wash after.

This is the only reason for using dot5 silicon.

Dot5 should only be used in systems that are designed or modified for dot5. Typical mod would be moving the master cylinder seals back towards the pedal by machining the piston to allow the seal to clear the inlet port fully. Normal road use is fine but because of compressibilty of silicon it's not suitable for racing because the fluid takes to long to decompress which makes precision braking impossible.

Harley Davidson use dot5 but the lines are short. To race a Harley a change to dot4 is necessary

Dot5 in any RR is likely to be a disaster. No dot5 supplier will recommend Dot5 in a Shadow.

Not sure exactly why, but I imagine the pump out put per jerk will be lower.

Dot5 can also retain air and often bleeding takes overnight rests hoping the entrained air pops out. Which because the only fluid I will reuse is antifreeze, expensive. Any fluids I take out are scrap.

(Message approved by david_gore)
Top of pagePrevious messageNext messageBottom of page Link to this message

David Gore
Moderator
Username: david_gore

Post Number: 1551
Registered: 4-2003
Posted on Saturday, 07 March, 2015 - 08:19 am:   Edit PostDelete PostView Post/Check IP

Re DOT5 silicon brake fluid, Bill Coburn has previously discussed a certain Phantom V that had DOT5 used in the hydraulic system with the inevitable disastrous results elsewhere in this Forum.

One of the main problems apparently is DOT 5 and water do not mix unlike DOT3/DOT4 and any condensate/moisture that gets into the fluid remains purely water. When the fluid gets hot, the water turns to vapour meaning pressure transfer through the fluid disappears as the vapour is compressible whereas the fluid is not.

Imagine the feeling in these circumstances when you need to use the brakes and nothing happens..............................
Top of pagePrevious messageNext messageBottom of page Link to this message

Bob UK
Unregistered guest
Posted From: 94.197.120.94
Posted on Saturday, 07 March, 2015 - 12:03 pm:   Edit PostDelete PostView Post/Check IP

A lot of diyers see the hydroscopic nature of dot as a fault when it's intentional.
silicon is simply not a good substitute for dot. It's long life means NO bleeding and water build up or regular bleeding and Silicon is not cheap. It even froths when pouring.

I can imagine the hydraulic power station full of froth which takes ages to move the pistons. The rams would be like gas springs. Add two mentos mints for full effect.

My car is on RR363. Soon to be yak363. The system apart from some hoses is perfect and I hardly top up the dot. I think the constant ram action due to saggy springs and regular
use is why I get no trouble.

I am not constantly maintaining the system, all I do is a visual and maybe retract the pistons and rattle the pads about. Apart from a fluid change every 2 years. Handbrake calipers like to part seize though, soon fixed with a wiggle and a spot of oil.
I have 4 sets of 4 pads, mintex. No spare rears but the present one's are less than a 1/4 worn.
It's no more work than doing my jeep brakes. Very much a quick visual every 6 weeks and forget. Sometimes I grease the nipples as well if in the mood for greasy hands. I never apart from the hand brake find anything to fix. The brakes feel like a car without a servo but powerful. It will stop as fast as tyre grip allows.
some shadows I have driven have had no real brake maintenance for years. Generally the owners fix when lights flicker or the brakes drag or a leak Even then stuff the pedal in the floor and the front wheels lock.

Very robust system with huge reserve capacity, and easy to maintain and repair. Everything comes apart easy, except the spheres but once a new set is fitted one can forget for years plus they can be recharged only in quite a few years time. The discs last well.
so with a bit of luck a Shadows brakes will last for years with normal car brake maintenance. And normal car brake money. Worth sticking a pressure gauge in the ACV say when doing the year dot Change. Plus if the system is pumped down and the pedal held down and engine started one can feel the pumps pulse as the pedal kicks. I sometimes do this when waiting in car parks for the wife to arrive. A quick system check without getting out of the car.
My fast ride height is fitted to neutral and park. Before the hoses got blocked. If I sat on the rear bumper the car levels in about 2 mins. Then get off the bumper and down it goes. An extra bit of ram exercise. It works one or two times with engine off. If I sit on the bumper with hydraulic 2 lighgt on with engine just started then pump pulses can be felt as the car levels.
if the system is depleted then then when started the level in the tank goes down.

if the ride height adjuster nut is loosened then the ride height can be made to go up and down which purges air into the return to tank.
These little easy to do tests tells me a lot about the health of the system and how it actually works. Plus a pressure gauge can be used anywhere in the system to check and understand more.

Note Ride height. do not remove adjustor nut and use bigger movement of the adjuster rod because the levers spindle may disengaged with the valves piston. I am guessing this is the case. Sure I read it somewhere.

So if you haven't fallen asleep due to boring post. Shadow hydraulic maintenance is easy with only one special tool, a pressure gauge.

Happy brake repairing, because the system is easy diyable.


Lhm systems are about the same as dot apart from the rear struts which are rams plus a gas spring all easy stuff as well except lhm likes to leak a bit. so maintenance the same Plus a visual of abs wiring.

Pep talk over and I hope anybody reading who is not confident with brakes is now more confident.

Dave I read about the disaster Bill Coburn had with silicon and it shows how much aggravation can caused by dot5 and it impossible to fully remove without using nasty chemicals

(Message approved by david_gore)
Top of pagePrevious messageNext messageBottom of page Link to this message

David Gore
Moderator
Username: david_gore

Post Number: 1553
Registered: 4-2003
Posted on Saturday, 07 March, 2015 - 12:45 pm:   Edit PostDelete PostView Post/Check IP

"Note Ride height. do not remove adjustor nut and use bigger movement of the adjuster rod because the levers spindle may disengaged with the valves piston. I am guessing this is the case. Sure I read it somewhere." - Bob

Yes you did read this on this forum in one of my posts many years ago when I told the story of how I blew the end off a height levelling valve due to incorrectly connecting the pipes after replacing them and manipulating the adjusting arm manually while the linkage rod was disconnected. The valve spool disengaged from the actuator and flew out knocking the complete end of the valve body off.

Expensive lesson well learnt...........
Top of pagePrevious messageNext messageBottom of page Link to this message

David Lacey
Experienced User
Username: dlacey

Post Number: 46
Registered: 11-2010
Posted on Thursday, 18 June, 2015 - 06:34 pm:   Edit PostDelete PostView Post/Check IP

All,
Here's an update:
I have assembled the fluids as best I can, I couldn't get a DOT4ESL, but I do have a DOT5.1 [a hi boiling glycol].
I will prepare the samples this weekend & take to the lab next week. It will be a blind study with 2 DOT3 controls.
Top of pagePrevious messageNext messageBottom of page Link to this message

Brian Vogel
Grand Master
Username: guyslp

Post Number: 1404
Registered: 6-2009
Posted on Thursday, 18 June, 2015 - 11:19 pm:   Edit PostDelete PostView Post/Check IP

David,

Will be eagerly awaiting the test results.

Brian
Top of pagePrevious messageNext messageBottom of page Link to this message

Robert Noel Reddington
Prolific User
Username: bob_uk

Post Number: 141
Registered: 5-2015
Posted on Friday, 19 June, 2015 - 05:29 am:   Edit PostDelete PostView Post/Check IP

The boiling point of the base dot type brake fluid used appears not to be a problem. Because as some us suspect should the RR363 or Yak milk boil then the reserve pressure in the ACV will take up the slack. So 5.1 super duper dot brake fluid is probably not necessary.

The dry boil points can be misleading. Because some brake fluids boil point falls quicker when the fluid sucks damp up. Which starts as soon as its put in the car.

Max is 3.7 % water and at 8% the boil point is about the same as water.

Always remember that the hygroscopic nature of Dot brake fluid is intentional.

Dot brake fluid has additives that combat corrosion. The sludge in the brake fluid tank is in part the dead bodies of the additives.

I am not sure about this bit. If the RR363 is changed and sludge is present then the additives in the new RR363 will then work on the sludge and be wasted, and added to the sludge. Tank cleaning is so important.

It will be interesting to see the test results.
Top of pagePrevious messageNext messageBottom of page Link to this message

Randy Roberson
Grand Master
Username: wascator

Post Number: 449
Registered: 5-2009
Posted on Friday, 19 June, 2015 - 10:54 am:   Edit PostDelete PostView Post/Check IP

I like Bob's guts and confidence of purpose. I am going to DOT 3 with castor oil mixed in.
Castrol has already given the formula away: Castor oil ethoxylated propoxylated mixed into DOT 3. This castor oil has a CAS number and it is commercially available in bulk. This stuff I predict is very cheap to make. The problem for a huge corporation is the sales are less than miniscule, and given the demands of overhead costs, testing, government paperwork, certification, insurance, lawyers, etc etc. it is not worth fooling with. Any number of smaller chemical manufacturers: private label makers, etc could make it for Bentley; alternatively Castrol could make the formula or permission to blend it available to the big RR clubs if they would.
Meanwhile I am comfortable with my version of the Magic Mixture.
Interesting that every bottle of RR363 I have seen was labeled "Made in USA".
Let fire burn and cauldron bubble...
Top of pagePrevious messageNext messageBottom of page Link to this message

Robert Noel Reddington
Prolific User
Username: bob_uk

Post Number: 143
Registered: 5-2015
Posted on Saturday, 20 June, 2015 - 04:32 am:   Edit PostDelete PostView Post/Check IP

Dot brake fluid is only made by a very limited number of oil firms.

I was once told only 3 firms in the world make the base for glycol type antifreezes.
I don't know if this is true

There is an amazing range of dot brake fluids. I use Comma DOT 4. Because its about the cheapest locally and is available from 1\2 litre to 5 litre cans.

I believe Dot 3 is available from Wall Mart at very cheap prices. This fluid is perfectly OK ---- by law it has to be.

Castor Oil EP is readily availble so as I said Happy days.

My confidence comes from that the car is a Rolls Royce and they wouldn't have attracted 30,000 customers if the brakes were no good. In any case my brakes work fine.
Top of pagePrevious messageNext messageBottom of page Link to this message

John Beech
New User
Username: jbeech

Post Number: 3
Registered: 10-2016
Posted on Friday, 04 November, 2016 - 04:40 am:   Edit PostDelete PostView Post/Check IP

Late to this thread. BobUK's post led me to start Tootsie, open the trunk, and sit on the edge. Down we settled and back to level again as the system raised the aft end - sweet! My wife's Mercedes estate does the same thing but with air whilst being 4 decades newer. This RR is amazing when you realize this followed the Silver Cloud, an auto with distinctly 50s level technology. In fact, my Silver Shadow compares very well in terms of suspension and brakes to another car I once owned, a 1966 Maserati Sebring, which also had four wheel independent suspension and disk brakes all around. But while that was a GT, my Roller is a sedan . . . very impressive!

Finally, what is YAK363, and is it a reference to a joke about yak-milk I read elsewhere? Anyway, someone please clue me in.
Top of pagePrevious messageNext messageBottom of page Link to this message

Jan Forrest
Grand Master
Username: got_one

Post Number: 943
Registered: 1-2008
Posted on Friday, 04 November, 2016 - 09:32 am:   Edit PostDelete PostView Post/Check IP

Had you read the bulk of this thread you would have determined that YAK363 is based on Yak milk - kind of.

In actuality it's a home made version of the original Castrol RR363 which is getting difficult (and expensive) to obtain. It's partly based on hearsay evidence that RR363 is a mix of standard DOT 3/4 brake fluid and castor oil. Admittedly the castor oil has been chemically altered, but since the 'real thing' is only available in industrial quantities we ignore the difference and use standard BP oil.

We get the mix - up to 20% in warmer climes - from the Citroen DS forums where aficionados of the marque have been using for years if not decades. Some brave souls have even tried pure brake fluid, but due to the lack of any significant lubricating qualities it's not recommended.
Top of pagePrevious messageNext messageBottom of page Link to this message

Jeff Cheng
Experienced User
Username: makeshift

Post Number: 50
Registered: 2-2016
Posted on Friday, 04 November, 2016 - 12:13 pm:   Edit PostDelete PostView Post/Check IP

After looking at the retail prices of getting RR363 to my door, the thought of making my own DOT3+Castor is becoming more appealing.

While available, I do still plan on using RR363 for routine annual flushes. I am however considering making up several litres of DOT3+Castor as backup and to carry as part of my road kit (for those 'top up every 5 miles and limp it home' scenarios).

Can I assume that RR363 and DOT3+Castor can be mixed with no adverse affect?
Top of pagePrevious messageNext messageBottom of page Link to this message

David Gore
Moderator
Username: david_gore

Post Number: 2290
Registered: 4-2003
Posted on Friday, 04 November, 2016 - 06:08 pm:   Edit PostDelete PostView Post/Check IP

Jeff,

Use straight DOT3/DOT4 fluid for flushing the system and open all bleed screws when draining the system before refilling with RR363/YAK363.

When refilling the system, use a vacuum extractor if you have one or beg/borrow one [stealing is below the behaviour expected from a R-R/B owner] if you do not have access to this tool.

It is possible to gravity bleed all circuits however patience is a virtue in this situation. Refer the information on hydraulic system bleeding in the workshop manual TSD2476 which is a free download from the Technical Library if you have not already done so plus the numerous posts on this topic in our Forum:

http://rrtechnical.info/sy/tsd2476/tsd2476hires.htm

I am not aware of any problems arising from mixing RR363 and the "home brew" DOT4/Castor Oil alternative.
Top of pagePrevious messageNext messageBottom of page Link to this message

John Beech
New User
Username: jbeech

Post Number: 7
Registered: 10-2016
Posted on Saturday, 05 November, 2016 - 01:15 pm:   Edit PostDelete PostView Post/Check IP

David,

The link you provided is labeled 04B and differs from the one I found for SY cars, which is labeled 004. This is the one I have been using.
http://rrtechnical.info/sy/tsd2476/tsd2476.htm

I note the name appends 'hires'

Moreover, I believe there's mention of 04B being a newer version but I couldn't find the link to this 04B manual in the menu so absent your post I'd probably never know about it. Anyway, is it indeed a later copyright of the SY manual, or merely a heavier weight (hires) version of the same thing? I wonder because I'm the present caretaker of SRX6816 and inquiring minds want to know!
Top of pagePrevious messageNext messageBottom of page Link to this message

David Gore
Moderator
Username: david_gore

Post Number: 2291
Registered: 4-2003
Posted on Saturday, 05 November, 2016 - 03:57 pm:   Edit PostDelete PostView Post/Check IP

John,

The link I provided is to a high-resolution copy scanned from an original TSD2476 manual [2nd Edition].

The high resolution is especially valuable whenever you have to view a wiring diagram as you can enlarge the page and the fine detail remains legible after enlargement.

As you have an early production vehicle, you need an original first edition of TSD 2476 as the later editions were edited to remove information relevant to the early cars and information relating to the later cars included.

Unfortunately, the workshop manuals for the Shadows lagged behind the frequent variations in vehicle specification that occurred during the entire production run. The electrical diagrams are particularly afflicted by this problem and it is often beneficial to look at the wiring diagrams for the next higher set of chassis numbers to find a diagram the resembles the wiring in your particular car.
Top of pagePrevious messageNext messageBottom of page Link to this message

Jean-christophe Jost
Experienced User
Username: jc_jost

Post Number: 26
Registered: 3-2016
Posted on Monday, 07 November, 2016 - 07:36 pm:   Edit PostDelete PostView Post/Check IP

Dear all,

Just to be curious : How do you deal with an overdose of castor oil (30% ...! castor poured in the system) ?

This case was submitted recently by a member on another RR forum, with no reply.
Top of pagePrevious messageNext messageBottom of page Link to this message

Jonas TRACHSEL
Frequent User
Username: jonas_trachsel

Post Number: 100
Registered: 2-2005
Posted on Monday, 07 November, 2016 - 09:44 pm:   Edit PostDelete PostView Post/Check IP

Jean-Christophe
Dilute it with more DOT 3/4 until the mixture ratio is what you were anticipating. So easy.....
Top of pagePrevious messageNext messageBottom of page Link to this message

Omar M. Shams
Grand Master
Username: omar

Post Number: 895
Registered: 4-2009
Posted on Tuesday, 08 November, 2016 - 03:40 am:   Edit PostDelete PostView Post/Check IP

unless of course the reservoir is full. In which case you will need to drain the reservoir as best you can and then refill with Dot 3/4 to the required concentration.
Top of pagePrevious messageNext messageBottom of page Link to this message

Jean-christophe Jost
Experienced User
Username: jc_jost

Post Number: 27
Registered: 3-2016
Posted on Tuesday, 08 November, 2016 - 05:46 am:   Edit PostDelete PostView Post/Check IP

Thanks for both replies, the implicit question was in fact how do you drain/clean an "oily" system
Top of pagePrevious messageNext messageBottom of page Link to this message

David Gore
Moderator
Username: david_gore

Post Number: 2292
Registered: 4-2003
Posted on Tuesday, 08 November, 2016 - 06:13 am:   Edit PostDelete PostView Post/Check IP

Flush with acetone and immediately flush again with straight DOT4 and drain before filling with RR363/YAK363.
Top of pagePrevious messageNext messageBottom of page Link to this message

Chris Miller
Grand Master
Username: cjm51213

Post Number: 437
Registered: 5-2013
Posted on Tuesday, 08 November, 2016 - 06:21 am:   Edit PostDelete PostView Post/Check IP

Acetone? Seriously? You don't think that will damage a huge number of seals?
Top of pagePrevious messageNext messageBottom of page Link to this message

Christian S. Hansen
Grand Master
Username: enquiring_mind

Post Number: 406
Registered: 4-2015
Posted on Tuesday, 08 November, 2016 - 11:58 am:   Edit PostDelete PostView Post/Check IP

If the system is "oily", that is, too high in the concentration of oil, how does one determine what the relative concentration is anyway?

What is the symptom that causes this person to conclude that the system is "oily" or containing the wrong concentration?.

Seems to me that the only solution is to drain the sytem of the fluid of suspect concentration and start over with properly premixed fluid.

If at first you don't succeed...try, try again...

What am I not grasping here?
Top of pagePrevious messageNext messageBottom of page Link to this message

Geoff Wootton
Grand Master
Username: dounraey

Post Number: 1461
Registered: 5-2012
Posted on Tuesday, 08 November, 2016 - 03:05 pm:   Edit PostDelete PostView Post/Check IP

I agree with Christian here. I think it is important to get the concentration right.

In answer to Jean-Christophe's question, my method for draining the system is to remove the top of the reservoir and use a turkey baster to remove as much fluid as possible. Wipe out the reservoir with paper towels and refill with fresh fluid. Then bleed the brakes until fresh fluid comes out each line. I guess to be super clean, carry this operation out the first time with dot3/4 and then finally with RR363/YAK363/OMAR363, depending on your preference and size of wallet.

Geoff
Top of pagePrevious messageNext messageBottom of page Link to this message

David Gore
Moderator
Username: david_gore

Post Number: 2293
Registered: 4-2003
Posted on Tuesday, 08 November, 2016 - 05:55 pm:   Edit PostDelete PostView Post/Check IP

Chris,

Acetone is the flushing agent of choice for removing the DOT5 silicone fluid added to some R-R hydraulic systems by mechanics thinking this was the best alternative to RRR363.

Bill Coburn used copious quantities of Acetone to successfully flush the braking system of a certain Australian Phantom V after DOT5 was used to replace the RR363. To the best of my knowledge, the use of Acetone did not have any adverse effects on the seals in the system.
Top of pagePrevious messageNext messageBottom of page Link to this message

Omar M. Shams
Grand Master
Username: omar

Post Number: 898
Registered: 4-2009
Posted on Wednesday, 09 November, 2016 - 03:39 am:   Edit PostDelete PostView Post/Check IP

Two options that I would consider are as follows:
1- Unscrew the lid off the reservoir and then siphon the contents of the tank out.

2- Undo the hose supplying the pumps with oil from the reservoir and let the oil drain.

The siphon option seems the least problematic choice to me.
Top of pagePrevious messageNext messageBottom of page Link to this message

Jean-christophe Jost
Experienced User
Username: jc_jost

Post Number: 28
Registered: 3-2016
Posted on Wednesday, 09 November, 2016 - 06:41 am:   Edit PostDelete PostView Post/Check IP

Christian,

Maybe I wasn't clear. I was referring to a 30% castor oil mixture done by mistake by some user . Did he run the engine? I don't know, but I guess yes.

And again thanks for the replies. I'll get back to him with your advices.
Top of pagePrevious messageNext messageBottom of page Link to this message

Christian S. Hansen
Grand Master
Username: enquiring_mind

Post Number: 407
Registered: 4-2015
Posted on Wednesday, 09 November, 2016 - 07:47 am:   Edit PostDelete PostView Post/Check IP

Thanks. Put another way, he specifically mixed up at 30% batch and that is how he knew the relative concentration.

Accordingly, drain the system as much as possible and refill with a properly mixed batch. Under the circumstances, I would imagine that the acetone bath is unnecessary since the issue is not a contaminant that must be flushed, but rather simply the incorrect mixture of the proper components. Drain. Refill. Good to go.
Top of pagePrevious messageNext messageBottom of page Link to this message

Jeff Cheng
Frequent User
Username: makeshift

Post Number: 53
Registered: 2-2016
Posted on Thursday, 10 November, 2016 - 08:35 pm:   Edit PostDelete PostView Post/Check IP

So I (somewhat) made the switch to YAK363 today and thought document my initial impressions.

I completely emptied and cleaned the reservoir today, refilling with a mix of 90% Nulon Super DOT4 and 10% castor oil from the chemist. Since I have not bled the system yet, I replaced ~2L of the fluid (saggy rear end). The last fluid change was in 2013 with RR363 after a height ram replacement.

Cold start:
My rear pump taps when cold, usually going quiet when the water temp hits 75*c. No change with the YAK363.

Operation:
No noticeable change in 'feel' or performance.
My rear rams ocassionally groan, so I will see whether that improves at all.

Misc findinds:
When I got SRH236505 6 weeks ago, doing the 'brake pump test' showed 90 pumps before the Brake 1 lamp lit, and 120 before Brake 2.
I tried it again after the fluid change and a quick 5mile drive to mix it all, with results e 40 pumps (Brake1) and 120 pumps (Brake2).
I wonder whether the pressure switches may have been sticky with lack of use (switching at 90 pumps when it should be 40), and the fresh fluid restored correct operation.

On a fully discharged system and hot engine (low idle), it took ~90sec after start for the lights to go out. I repeated this with a very slightly manually raised idle with a 'lights out' time of 60 sec. On autochoke/high idle before the fluid change, lights out was around 35-40sec, so I have no concerns there with the low hot idle causing the longer time.

As a side note, my car had only covered 2000miles in the last 10 years, with a service every 2 years. The last fluid change was in 2013 with RR363 and the reservoir was quite dark with silt, but no sludge. I have driven 600miles in the last 6 weeks alone, so I'm sure the car is still waking up.

If anyone is curious, I will post updates of anything I notice with the transition to YAK363. I am taking the car to a specialist for service in the new year, so I intend to have him do a complete bleed/flush with the YAK363.

Obligatory clean reservoir pic:
reservoir

P.S. does anyone know the deal wit the third reservoir filter? My car is SRH23650, so it should not have the master cylinder anymore...?
Top of pagePrevious messageNext messageBottom of page Link to this message

Geoff Wootton
Grand Master
Username: dounraey

Post Number: 1465
Registered: 5-2012
Posted on Friday, 11 November, 2016 - 12:56 am:   Edit PostDelete PostView Post/Check IP

Hi Jeff

That's a mystery. The documentation says the master cylinder was deleted on car 22118. Maybe some cars got through the net. I think the only way you will be able to tell is when you next have the rat trap cover off. Your reservoir looks really good - no pitting at all and the filters look in good shape - they often collapse.

Geoff
Top of pagePrevious messageNext messageBottom of page Link to this message

Paul Yorke
Grand Master
Username: paul_yorke

Post Number: 1676
Registered: 6-2006
Posted on Friday, 11 November, 2016 - 01:29 am:   Edit PostDelete PostView Post/Check IP

Jeff, is it blanked off underneath or has it got a larger pipe leading from it?
Top of pagePrevious messageNext messageBottom of page Link to this message

David Gore
Moderator
Username: david_gore

Post Number: 2297
Registered: 4-2003
Posted on Friday, 11 November, 2016 - 07:20 am:   Edit PostDelete PostView Post/Check IP

Jeff,

The rear pump "taps" may be either from the pump operating against minimal back pressure from the accumulator or excessive push-rod clearance.

The reduced pump down count suggests a faulty accumulator pressure relief valve or low gas pressure in the accumulator.

The "groan" from the rear rams is characteristic of fluid that has lost its lubrication properties. You need to properly bleed the rams to ensure the new fluid is present and then see if the problem abates after 20 or more substantial ram activations. Groans/taps from the rams were the first indication of the "new formulation" RR363 from Castrol referred to elsewhere in this forum not functioning as well as the older formulation.
Top of pagePrevious messageNext messageBottom of page Link to this message

Jeff Cheng
Frequent User
Username: makeshift

Post Number: 54
Registered: 2-2016
Posted on Friday, 11 November, 2016 - 08:13 am:   Edit PostDelete PostView Post/Check IP

Geoff & Paul,

On closer inspection, the outlet for the third filter has been blanked off. I'll be sure to poke around the rat trap next time the car is up.

HOWEVER, the third filter was showing the most damage (colapsed AND torn vs slight collapse for the other two). My only explanation may be a previous owner seeing one of the usual filter damaged, swapped it with the unused third filter. Mysteries...

David,
I will be taking the car to a specialist in the new year, and plan on supplying him with ample YAK363 to do a complete system flush. I will be sure request him give me a condition report on the accumulators, since he is retired/working from home and charges reasonable rates. 40 pumps for now doesn't seem like reason for panic at this stage.

The rams are groaning considerably less now compared to when I first got the car (almost every bump vs very occasionally now), so maybe that was just from lack of use. Will monitor in the meantime and note any changes. Since my car has a saggy bum after being parked for a few days, would this action somewhat mix the fluid in/out of the rams?

My reason for the switch is availability of RR363 in Aus. The cheapest way I've found is to order individual bottles per order through Flying Spares, applying the 'FSAPP10' discount code for £10 off per order.
Top of pagePrevious messageNext messageBottom of page Link to this message

David Gore
Moderator
Username: david_gore

Post Number: 2298
Registered: 4-2003
Posted on Friday, 11 November, 2016 - 07:32 pm:   Edit PostDelete PostView Post/Check IP

Jeff,

Bleeding is the only fully effective way of getting fresh fluid into the rams.

The circuit is "dead-ended'" and, once fluid is in the rams, it will stay there and shuttle back and forwards wholly within the hydraulic pipes until the bleed nipple is opened and the fluid released to allow fresh fluid from the reservoir to access the ram.

Add Your Message Here
Post:
Bold text Italics Underline Create a hyperlink Insert a clipart image

Username: Posting Information:
This is a public posting area. Enter your username and password if you have an account. Otherwise, enter your full name as your username and leave the password blank. Your e-mail address is optional.
Please quote Chassis Numbers for all vehicles mentioned.
Password:
E-mail:
Options: Enable HTML code in message
Automatically activate URLs in message
Action: