CH12/LHS2/RR363 substitute

[Jan Forrest]

For those who run earlier models needing vegetable/synthetic hydraulic fluid this page ...

http://www.candokaraoke.com/fluid.html

... may pique your curiosity.
Many have expressed concerns that RR363 is not 'made like it used to be'- perhaps due to the substitution of the original castor oil with a synthetic substitute.
As the basic design of the Rolls Royce hydraulic system is virtually identical to the one fitted to early Citroen DS/ID models it is reasonable to assume that the same fluid should be used in any varient of it.
The author of the site has concluded that a ratio of 9-10% of castor oil in otherwise pure DOT4 hydraulic fluid will give an identical viscosity to the original CH12/LHS2/RR363 with no known adverse reactions. Admittedly some Australian enthusiasts have gone as high as 15-18% castor oil with similar results although it has been noted that this quantity might be too high in many countries if the ambient temperature drops below freezing, when 'clumping' of the castor oil has been observed.
So far I've obtained 5 litres of DOT4 and I'm waiting for delivery of the 500ml of castor oil to mix into it. Once done, and time permitting, I shall flush through the hydraulic system of my Shadow 1 and replace all the old fluid with the new mix. Then after a few hundred miles I shall report back with my observations.

[Omar Shams]

I have read the notes with interest. It has been a year since the above posting, and I am dying to know if the experiment has worked. Shall I swap the RR363 in my Wraiths to Dot4 and 15% Castor oil? I have already bought the castor oil.......... waiting to hear form someone please

[Allan Maclean]

I have 1970 shadow and have noticed a very significant improvement in overall terms.This is due to the addition pure caster oil to dot 4 penrite.

[Jan Forrest]

"I have read the notes with interest. It has been a year since the above posting, and I am dying to know if the experiment has worked. Shall I swap the RR363 in my Wraiths to Dot4 and 15% Castor oil? I have already bought the castor oil.......... waiting to hear form someone please "

The percentage of castor oil depends on ambient temperatures the car experiences. In any part of the world where the temperature dips below 5C that should not exceed 10%. There is little advantage to using more unless you already change the fluid twice per year: Before and after Winter.

NB: The fluid should be changed at least EVERY 2 years. More often in humid climates as it is strongly hygroscopic.

Unfortunately shortly after my original post I had a ... difference of opinion ... with the UK Revenue & Customs and the car has been stood for a full year without the opportunity to do any work on it. Luckily it is due for return this Friday when I shall be bleeding the whole system plus doing a few other jobs to recommission it for the road after its long sleep.
One important note! This susbstitute MUST NOT be used in any car with a system meant to be used with LHM (mineral fluid). There should be notices on the top of the reservoir to this effect. Ignore these warnings and the whole system - brakes and suspension - will require new seals and rubber hoses in a matter of weeks! The same goes for RR363 cars which are refilled with LHM.

[Allan Maclean warrnambool]

I also have a 1970 shadow and have added 2% of castor oil penrite dot 4 fluid. Changes noticed over a period of some 12 months add up to a better car in overall terms.Including the steering and cornering.