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David Gore
Moderator
Username: david_gore

Post Number: 2400
Registered: 4-2003
Posted on Sunday, 05 February, 2017 - 08:51 am:   Edit PostDelete PostView Post/Check IP

Patrick,

I have started a new topic to cover your pressure limiting valve problem as it is not relevant to a Shadow 2 and transferred the relevant posts as below.
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Patrick Francis
Experienced User
Username: jackpot

Post Number: 21
Registered: 11-2016
Posted on Saturday, 04 February, 2017 - 04:28 pm:   Edit PostDelete PostView Post/Check IP

Hi guys (or all? - any lady owners out there?)
RR SRH 17968
I have just replaced my self levelling ram seals etc and when bleeding the rear reservoir system, on a 4 post lift with car level, everything bleeds as it should except the rear lower cylinders which eject very little fluid. Funnily enough, the brake pedal actually goes down a bit when the nipple is cracked, but not a lot comes out.
At first I thought I was bleeding the master cylinder cicuit by mistake - but double checked that .
I am guessing the decelleration conscios valve?
Anyone had this happen?
Ta
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David Gore
Moderator
Username: david_gore

Post Number: 2398
Registered: 4-2003
Posted on Saturday, 04 February, 2017 - 07:20 pm:   Edit PostDelete PostView Post/Check IP

Yes - you have to release the pressure in the accumulators with a pump down test, open the rear bleed valves, raise the rear end of the car to give more inclination to the pressure limiting valve and gently tap the valve body with a hammer so the ball inside the body rolls back down from the fluid exit fitting for the rear brake line.

Next time, manually gravity bleed/vacuum bleed the system with the accumulators discharged. If you try to bleed the system when pressurised, the ball is forced back against the discharge port and usually jams necessitating the previously described "persuasion" to return it to its proper position in the valve body above the fluid inlet port.

If the ball does not fall back, disassembly of the valve is the safest way to remedy to problem; do not use compressed air to push the ball back as errant hydraulic fluid in your eyes is not conducive to good future eye sight......
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Patrick Francis
Experienced User
Username: jackpot

Post Number: 22
Registered: 11-2016
Posted on Sunday, 05 February, 2017 - 01:40 am:   Edit PostDelete PostView Post/Check IP

Thanks David. Without looking at it yet, did you mean raise the front end of the car - would this not encourage the ball to fall backwards easier? Or should it fall forwards?
Ta

Looking at it standing on my head with the car upside down of course.
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David Gore
Moderator
Username: david_gore

Post Number: 2399
Registered: 4-2003
Posted on Sunday, 05 February, 2017 - 08:44 am:   Edit PostDelete PostView Post/Check IP

Patrick,

I specifically meant raising the rear of the car body to increase the angle of inclination of the valve body to allow gravity to do the job for you. The ball rises in the valve body when the brakes are applied and falls back under gravity and reverse fluid flow from the callipers when the pedal is released; if the pedal is applied too heavily, the ball closes the fluid exit port to the rear brakes to prevent excessive pressure locking the rear brakes.

When I had this problem on DRH14434 shortly after it was transferred from my father-in-law's estate, I had to dismantle the valve to release the ball as the brake system was full of green "flubber" slime due to the hydraulic fluid not being changed for a long period of time. The "slime" restricted the ball rolling back freely and the ball eventually became "glued" to the discharge end of the valve and blocked the flow of fluid to the rear callipers.

I found acetone was very effective in dissolving and removing the "slime" from the brake lines and valve bank. All callipers, the low pressure master cylinder and pressure limiting valve were stripped, cleaned and re-assembled with new seals and the reservoir cleaned and the filters replaced.

I hope in your case that the problem is due to excessive pressure in the brake system pushing the ball up to the discharge port and wedging it in the valve body when you started bleeding the brakes. I hope you do not have the problem of degraded brake fluid from long periods between fluid changes and/or lack of use if the car had been stored for long periods of time without being driven on a regular basis. This was the situation with DRH14434 as it had to be kept in the UK for 2 years after it was purchased second hand to qualify for reduced import duty when it was shipped to Australia. The car was in poor condition when F.I.L. purchased it as the low cost on the purchase documentation would minimise the amount of import duty that would have to be paid when it finally arrived here.

My subsequent experience with this car reinforced the advice given to purchasers of pre-owned R-R/B vehicles "every dollar you pay for a well-kept car in preference to a car in poor condition saves at least two dollars in repairs after acquisition."

.
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Alan Dibley
Experienced User
Username: alsdibley

Post Number: 41
Registered: 10-2009
Posted on Sunday, 05 February, 2017 - 07:14 pm:   Edit PostDelete PostView Post/Check IP

Um, deceleration causes the ball to rise towards the front of the car to block the port. I think you mean "raising the front of the car" to get the ball to move back from the port.

Or am I talking rot, again?

Alan D.
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David Gore
Moderator
Username: david_gore

Post Number: 2402
Registered: 4-2003
Posted on Sunday, 05 February, 2017 - 09:12 pm:   Edit PostDelete PostView Post/Check IP

Alan,

I have suffered a classic "Seniors Moment" although for a very good reason - over 20 years have passed since I overhauled the hydraulic system on DRH14434 and I had completely forgotten the layout of the "Deceleration Conscious Pressure Limiting Valve" [DCPLV] in the "rat trap".

Thanks to my trusty copy of TSD2476, my not-so-trusty-memory has now been re-educated with regard to which end of the car should be lifted and you are correct in stating front front of the car has to be lifted and not the rear to increase the inclination of the valve body to assist freeing the ball by gravity. For some reason the passage of time has reversed my memory of the valve orientation in the rat trap frame.

The images below show the orientation of the DCPLV on early and late Shadows - Item 12 is the DCPLV.

Early Shadow Brake Circuit

Early Shadow


Late Shadow Brake Circuit

Late Shadow


I will now do a "walk of shame" as penance for my error .

.
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Omar M. Shams
Grand Master
Username: omar

Post Number: 1055
Registered: 4-2009
Posted on Monday, 06 February, 2017 - 03:48 am:   Edit PostDelete PostView Post/Check IP

David mate - we can call it quits if you down a pint in one later on in September when we meet....

Omar
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David Gore
Moderator
Username: david_gore

Post Number: 2403
Registered: 4-2003
Posted on Monday, 06 February, 2017 - 07:50 am:   Edit PostDelete PostView Post/Check IP

Omar,

Unfortunately my name is not Bob Hawke [one of our past Prime Ministers who held the Oxford record for downing the contents of a yard glass in one go during his university days] and I enjoy savouring whatever amber fluid is in my hands at the time. I am looking forward to resuming my friendship with a pint of real ale whilst we are in the UK and this will be my drink of choice to make up for lost time. Only problem is real ale is not a beer that can be quaffed easily and a "technicolour yawn" is inevitable if I was to try this feat.
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John Beech
Prolific User
Username: jbeech

Post Number: 186
Registered: 10-2016
Posted on Monday, 06 February, 2017 - 08:22 am:   Edit PostDelete PostView Post/Check IP

I've only made one visit to the UK (a trade event at Sandown in London) but whilst there stayed at a nearby B&B and the lady pointed me to a neighborhood pub. I went every night during the week I was there and got to recognize the regulars, which to my complete surprise often came with wives and sometimes children in tow. Why a surprise? Simply because in my experience our local bars are mostly places for single men and women to drink and meet. My point? The beer was beyond excellent, it was superb. Easily the best of my life. Back stateside, I returned to my drink of preference, single malt whisky, served neat. This, because the beer here is such a comparative disappointment in both texture and flavor (it all seems very bitter to me - this due, I am told, to the influence of brewers using lots and lots of hops). Anyway, circumstances don't favor my making another trip to England in the near future so I will enjoy your meeting vicariously through this forum. Please hoist at least one for me!
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David Gore
Moderator
Username: david_gore

Post Number: 2404
Registered: 4-2003
Posted on Monday, 06 February, 2017 - 02:44 pm:   Edit PostDelete PostView Post/Check IP

John,

Like you, I am a great fan of the traditional British pubs and their family-friendly environment. The traditional Australian pub used to be a male-oriented "beer barn" with separate "ladies lounges" and children under 18 were not allowed on the premises due to licencing laws. Fortunately, this has changed and women now drink in the bars alongside the men and children can attend the bistro/restaurant facilities provided they are accompanied by an adult and do not consume alcoholic drinks. However, many do not have the "atmosphere" and serenity of the traditional British pubs.

My US long-time friend spent a considerable period of time working at Pabst in Milwaukee as a millwright and has also spent several years working here in Australia in the late 1960's before returning home.

When I visited him in Milwaukee in December 1974, I brought a quantity of various Australian beers for him and he arranged a back-shift beer tasting in one of the Pabst crib rooms and invited his mates from the other breweries to attend with samples of their own products.

Needless to say a great night was had by all especially myself as I was duty-bound to sample all the samples from the US breweries. To cut a long story short, the US contingent got thoroughly drunk on the Australian beer due to its higher alcohol content and I ended up as sick as a dog from the copious quantities of the lower alcohol US beer I consumed - I also felt the US commercial mass-market beer I sampled contained more chemical additives and was sweeter than our beer which might explain your dislike of the texture and flavour and my reaction to consuming excess quantities - I normally do not get hangovers unless I mix beer, wine and spirits during one session.

You can be sure there will be glasses raised many times during the get-together to acknowledge absent friends.
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Omar M. Shams
Grand Master
Username: omar

Post Number: 1059
Registered: 4-2009
Posted on Tuesday, 07 February, 2017 - 05:22 am:   Edit PostDelete PostView Post/Check IP

Indeed David.... many a raised glass for every one of our friends. By the end of the night we will be sozzled..... and we will repeat that every night.... although i may take a break on alternate evenings. I was always known as "the lightweight" at university.
We will have several raised glasses for John...
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David Gore
Moderator
Username: david_gore

Post Number: 2406
Registered: 4-2003
Posted on Tuesday, 07 February, 2017 - 07:46 am:   Edit PostDelete PostView Post/Check IP

Omar,

I will save the stories from my time in the steel industry and in the Pilbara region of West Australia where drinking was a compulsory part of our life for our get-together later this year.

However, due to recent medical problems and adverse affects on medication, I now have to be more circumspect when alcohol is available. Moderation in all respects is mandatory much to my regret....
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Geoff Wootton
Grand Master
Username: dounraey

Post Number: 1590
Registered: 5-2012
Posted on Tuesday, 07 February, 2017 - 08:22 am:   Edit PostDelete PostView Post/Check IP

Is the lunchtime drink still alive and well in the UK? It used to be the norm to nip down the pub for an often extended lunch break when I worked there. There was usually wine available for afternoon meetings. All this is an absolute no no in the US. I wondered if the "tradition" still held in the UK.

Geoff
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Paul Yorke
Grand Master
Username: paul_yorke

Post Number: 1733
Registered: 6-2006
Posted on Tuesday, 07 February, 2017 - 09:46 am:   Edit PostDelete PostView Post/Check IP

No more . . . unless you're taking the train home maybe?

Gone are the days of 'one for the road' !
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David Gore
Moderator
Username: david_gore

Post Number: 2407
Registered: 4-2003
Posted on Tuesday, 07 February, 2017 - 08:34 pm:   Edit PostDelete PostView Post/Check IP

Paul,

Same here in Oz..... the advent of mobile random breath testing killed the "one for the road" tradition unless you happened to choose a glass of water .

We also had a quaint law in NSW dating back to the horse and buggy era that stopped you from buying an alcoholic drink on Sunday in hotel/pub/club unless you were a "bona fide traveller". To be a bona fide traveller you had to be at least twenty [I have forgotten the exact distance] miles from home [a fair distance in the horse and buggy era], produce your driving license/other identification showing your address to the publican and sign a book, stating reason for travel. The unusual twist to this law was that it did not stop a bona fide traveller buying a drink for a local who happened to be in their home town licenced premises so there was a set routine for getting a traveller to buy a drink for a thirsty local; it was essential the publican did not see money changing hands between the traveller and local as this was held to constitute a purchase by the local which made it illegal so the publican/barman would pointedly turn their back at the appropriate time so they could truthfully say they never saw money change hands if challenged.

If the local constabulary happened to call into the licenced premises "to ensure the law was being implemented" with some refreshment while they were there, the local would spin a yarn that the traveller was a distant relative who had been passing through and dropped in unexpectedly to say "hullo" and break their trip.

Of course this just increased the number of drink drivers on any given Sunday travelling back and forward to the nearest "watering hole" adjacent to their home town. Sanity finally prevailed in the late 1960's/early 1970's and this law was repealed as it never achieved the desired objective and there were more breaches than observance.
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Patrick Ryan
Grand Master
Username: patrick_r

Post Number: 1024
Registered: 4-2016
Posted on Tuesday, 07 February, 2017 - 10:02 pm:   Edit PostDelete PostView Post/Check IP

Gents,
What David said is spot on.
This is why Australians love to drive long distances, even for a coffee.

Like many other kids, my siblings and I were always in the car for a drive to anywhere so mum and dad could have a drink and buy us lunch.

It is some of the fondest memories I have as a kid.

Much better than just going to the local, and it was a good run for dads car once a week.
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David Gore
Moderator
Username: david_gore

Post Number: 2409
Registered: 4-2003
Posted on Tuesday, 07 February, 2017 - 11:00 pm:   Edit PostDelete PostView Post/Check IP

I overlooked including the fact that, in the horse and buggy era, it was very common for the local publican to put the inebriated owner in their buggy/sulky/cart and let the horse take its sleeping owner home unaided as the horse knew the way home to its stable and the feed bin waiting for it when it arrived.

To avoid the wrath of an irate long-suffering wife, the owner would remain sleeping in the buggy/sulky/cart until morning before "facing the music" of a tirade [and a bucket of cold water kept solely for this purpose] from his partner when he finally walked through the door.

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