| Author | Message | |||||
     Robert Noel Reddington Grand Master Username: bob_uk Post Number: 496 Registered: 5-2015 |
POLY ALKYLENE GLYCOL. Polyalkylene Glycol. I was reading about PAG oil and DOT 5.1 Brake fluid was mentioned. Interesting. Is 5.1 a ready made substitute for RR 363. Price wise is about the same as RR 363. One aspect of using castor oil EP is that DOT 2 was castor oil based. DOT 3 isn't. Castor oil was removed from brake fluid because it is not stable. Ethoxylated Propoxylated castor oil is more stable. EP also means extra pale in castor oil world. Extra pure. And Dave Gores Extreme pressure. Maybe the secret ingredient of RR 363 is PAG. | |||||
| Bill Coburn Moderator Username: bill_coburn Post Number: 1580 Registered: 4-2003 |
Robert this whole 363 phase I sometimes wonder whether the whole exercise was a bloody nonsense! Here in the colonies in the colonies there is still no statement as to whether we scrap all the Shadows or convert them to mineral oil Worse some owners having heard mention of castor oil are applying it neat to their reservoirs! I have now seen three reservoirs that have been so treated and the resultant mess would confound the head keeper of the local sewerage works! It is only a matter of time before there is a complete brake failure and then the pundits will come out of the woodwork in droves. | |||||
| Brian Vogel Grand Master Username: guyslp Post Number: 1669 Registered: 6-2009 |
Bill, That there are people who will do the patently stupid, and without thinking, in almost any context is a given. You really can't fix stupid. There's not any controversy of substance about what the difference is between plain DOT3-type fluids and RR363. At this point there are enough people who have been successfully using YAK363 (90% DOT3/10% castor oil) and OMAR363 (85% DOT3/15% castor oil) for sufficient periods of time that they can be declared "safe and effective" if one chooses not to use RR363 and you live in an area that does not get frigidly cold when you intend to run the car. Mineral oil conversions are possible, but that carries issues of its own that, for me personally, make it not worth the effort. The cars will work fine with RR363 or YAK363 and continue to do so provided the fluid is changed at 2-year intervals in the majority of climates, once a year in very humid ones. I have not seen anyone, anywhere in writing propose that pure castor oil is an appropriate substitute for brake fluid. That some insist on trying it is entirely of their own volition and without having done even the most cursory research or analysis. You just can't fix stupid. Brian | |||||
| Robert Noel Reddington Grand Master Username: bob_uk Post Number: 501 Registered: 5-2015 |
The real problem is that Castrol won't spill the beans of exactly what RR363 is. Pun intended. I am suspicious about castor oil because of experience with Castrol R engine oil. Wakefield Oil made engine oil from castor beans. They called it Castrol. Castor oil when heat cycled starts to gum up and forms jelly. This used to happen with Castrol R. It had to be changed often. Providing the yak 363 is changed bi annually then fine. I suspect that if the yak 363 was left in a car used daily for say 5 years then one might find a lot of sludge and even bacteria. The continual heating and cooling is the reason. An expert on Silver Shadows said just use Dot 4. I find the whole 363 thing confusing because as I get settled with the idea of castor oil. I get a curved ball like PAG oil. And then there's the fact that DOT 4 was formulated for ABS pumps which must work once in a blue moon. The designers of brake systems take into account that brakes are often not serviced as they should be but still must work including the ABS. So the fluid used must have good oiling and corrosion resistance. Hence my attraction to plain DOT 4. Dot 5.1 has PAG oil which I am not sure why. The boiling points of 5.1 are higher than DOT 4. Is 5.1 more oily. I often read other forums only and have noticed that quite a few people seem to think that DOT brake fluid is corrosive to the system and not a lubricant. This is simply not true. | |||||
| David Gore Moderator Username: david_gore Post Number: 1738 Registered: 4-2003 |
Bob, It has always been my understanding the sole reason for the inclusion of castor oil in the hydraulic fluid was to act as a lubricant for the hydraulic pumps. As you would be aware, these pumps rely on minimal clearance instead of seals to control leakage past the piston so keeping wear in service to an absolute minimum would be an absolute priority. I suspect the early DOT 3 systems were afflicted by excessive leakage due to premature piston/bore wear after the cars were released resulting in the subsequent addition of castor oil to provide the necessary lubrication to reduce this wear. From my experience with hydraulic mining and construction machinery largely around the time the changeover from oil to water based hydraulic fluids occurred, I strongly suspect straight DOT 4 will have the same problems as the original DOT 3 - yes it will work but at the risk of reduced service life and expensive replacement costs. As always, better to be sure to be sure........ | |||||
| Brian Vogel Grand Master Username: guyslp Post Number: 1670 Registered: 6-2009 |
Bob, I don't know of any brake fluid manufacturer who will reveal exactly what their fluid contains. That's why DOT spec compliance has become the common metric by which brake fluid choice is made. The above being said, we know that RR363 is a DOT3 fluid with ethoxylated-propoxylated castor oil added. There's no doubt about that just based on the MSDS.
How anyone can touch any brake fluid and not recognize that it has lubricating properties is a complete and utter mystery. But, in the sage words of Henry Rosovsky: Never underestimate the difficulty of changing false beliefs by facts. Brian | |||||
| Robert Noel Reddington Grand Master Username: bob_uk Post Number: 503 Registered: 5-2015 |
I have just been thinking that maybe DOT 3 4 and 5.1 are actually a type of PAG oil. DOT 2 is castor and alcohol. The general opinion of bar stool mechanics is that water absorption of DOT is a minus point and not as I see it as a plus point. I don't bother saying anything because they will get uppity that someone has challenge their opinion. My brake fluid is genuine 363 its now 2.5 years old. I am about to strip the calipers down which will be the ideal time to flush and change. I can't get any 363 so I will most probably flush with dot 4 and then Yak 363. To be honest the price is not an issue. However if I must use Yak then the money saved is handy. Especially as DOT 4 is sold in 5 litre plastic cans at a saving over 1 litre bottles. Recently on the Spirit section a poster was enquiring about aviation red hydraulic oil. Common name Skydrol. I worked for Fairy Hydraulics who design and build military aero hydraulics. We used Skydroll fod testing stuff. The oil was most diffinately mineral oil. But in civil aviation red oil is phospate ester based and is not compatible with military red oil. So getting these two fluids mixed up is a disaster awaiting. Conversion to LHM is doable. Master cylinder cars included because the later Citroën 2CVs had LHM master cylinders and the brakes stopped the car fine. Good fun town car. Some of the seals in the AVCs are already LHM compatible. And the ride height could be quietly disconnected. Or a separate reservoir soley for the master circuit. But all the time there is a cheaper solution in DOT fluids with added whatever works I shall carry on as is. There's room to fit a Citroën swash plate pump which is driven by vee belt. Good LHM pump with ample capacity. It will easily run two ACVs. About 1/2 the physical size of an alternator. So if the worst comes to the worse there are solutions. A question. The acvs are fitted to the engine so that solid steel pipes from the pumps to the acvs can be used. But the prototypes had flexibles hoses. Were the acvs always mounted on the engine. I would think that maybe the acvs were body mounted at one stage. | |||||
| Mark Aldridge Prolific User Username: mark_aldridge Post Number: 253 Registered: 10-2008 |
Bob, try for RR363. http://www.ebay.co.uk/itm/Castrol-RR363-Brake-Fluid-for-pre-1980-Rolls-Royce-Bentleys-2-LITRES-2-x-1L-/281353434845?_trksid=p2141725.m3641.l6368 Mark | |||||
| Bob Reynolds Grand Master Username: bobreynolds Post Number: 335 Registered: 8-2012 |
"There's room to fit a Citroën swash plate pump which is driven by vee belt. Good LHM pump with ample capacity. It will easily run two ACVs. About 1/2 the physical size of an alternator. So if the worst comes to the worse there are solutions." What happens when the belt snaps? No brakes! The beauty of the RR system is that everything is duplicated, and not dependent on dodgy drive systems. AFAIK there is no difficulty in obtaining RR363 in the UK at the moment. | |||||
| Brian Vogel Grand Master Username: guyslp Post Number: 1671 Registered: 6-2009 |
Bob, When is the last time you had a belt of any kind break? Why does the rest of the automotive world use belt-driven brake pumps (or electric, in a few cases). Calling a belt driven brake pump system "dodgy" ignores common engineering practice. The accumulators in our cars, if set up properly and maintained, give quite a few applications of brakes before becoming played out. A belt break would be, worst case, not much different than a stall. All of the above is completely disjoint from the availability of RR363. The last batch seems to have made its way to suppliers worldwide at this point. I'm also not arguing for conversion of our braking systems, either. Brian | |||||
| Robert Noel Reddington Grand Master Username: bob_uk Post Number: 504 Registered: 5-2015 |
When the belt snaps on Citroën the accumulator takes over and a red light comes on which says STOP. Citroëns are safe. The Rolls- Royce version of this system is IMO badly laid out. The Accumulators and spheres are fitted to the Citroën engine with very easy access. My CX was playing up and I changed the sphere in 2 mins using an oil filter strap. Also the Citroëns because the hydraulics also run the suspension and power steering have a priority valve which if the pressure goes low it will reduce pressure and the steering will feel heavy and the STOP lamp will come on. All the pressure is diverted to the brakes which are mega powerful. Also the system on the Shadow would still have 2 spheres and 2 braking systems. Just one big pump. Belt drives are not dodgy and are very reliable. I have never actually ever had a drive belt snap in 50 years of driving and have rarely actually fitted new belts to any of my cars. The trick is to check the belts. Also look at the bottom of the V in the pulley if its shinny then the belt is riding too low and either or both pulley and belt are worn. The CX used a dedicated belt for the pump. The pump doesn't use much power and the belt has an easy life. Its driven off the camshaft at about 1/2 engine speed. I shall order some RR363 from my Castrol guy. I asked last week and she said maybe. Monday first thing get 363 on order. The belts on my Shadow are marked Rolls-Royce. They are at least 26 years old and are still good to go. I always use a fishing spring balance on belts. If the belt slips after then fit new bits as required. V belts are if fitted correctly very reliable. Serpentine belts were introduced so only one belt could be used thus shortened the engine length especially on front wheel drive cars. V belts mustn't be curved backwards so the arc of contact on a single V belt wouldn't be enough. The amount of room taken up by the belts and pulleys on a Shadow is quite a lot. But does give plenty of room to work on the front of the engine once the drives are removed. Can't remember weather the Citroën swash plate pump has 5 or 7 pistons. The RR only has two. A CX when started lifts itself very quick 5 seconds. If the ride height lever is moved with engine running and car at normal driving height then the changes to ride height are even faster. Also the bore of the pipe work is smaller. So the the Citroën pump has grunt. | |||||
| Randy Roberson Grand Master Username: wascator Post Number: 514 Registered: 5-2009 |
Castor oil, ethoxylated propoxylated is available from supply houses in commercial quantities. I just never found anyone who would sell me any in a reasonable quantity. CAS 72986-44-8 | |||||
| Robert Noel Reddington Grand Master Username: bob_uk Post Number: 524 Registered: 5-2015 |
Miller Oil call Dot 3 4 and 5.1 a PAG oil. One of the Citroën guys has suggested 150 PAG oil at 20%. What 150 PAG is I have no idea. I am glad RR363 is now available. Because I can stop reading all this confusing stuff on the net. Also these suggested additives are not cheap. So it would be easy to spend more than RR363 actually costs. |
RR363 MSDS - Most current I have