Accumulators & Valve Bodies for Rolls-Royce Silver Shadow & Bentley T Series

Everything you may need to know about Accumulator & Valve Bodies for Rolls Royce Silver Shadow & Bentley T series & what to consider when reconditioning one.
RH2343 & RH2390 & others can be found here.

We also have accumulators for mineral oil systems here.

“Hi there and welcome back! This time we are going to do a 3 part video about Hydraulic Accumulators & Valve Bodies. In the first video I’m going to talk about the assembly that we have got here & the second & third video we are going to take each unit broken down and look at the components in each and see what goes wrong with them.

This is a Valve Body and Accumulator assembly which is part of the braking system on Silver Shadows & Bentley T series. This is from a Silver Shadow II, which you can tell because it has got the longer filling cap and the shallower bowl. The other telltale sign is that on the Valve Body on the Shadow I models they have a Brake Pressure Switch that screws into the side here, on the Shadow II models that is located somewhere else so there is no hole there for the Brake Pressure Switch. There are two of these on the car, two pressure systems, the Brake Pump feeds high pressure fluid into the Valve Body here, the Valve Body regulates it and when it reaches the right pressure it returns back to the Reservoir.

It should have a 1000 psi stored in the Sphere. When the pressure starts being supplied to the Valve Body there is automatically a 1000 psi in the system. That will build up to 2,500 psi and drop back to around 2,300 and hold there. As soon as you start using the brakes it will drop and then when it gets below about 1,700 psi it will start to build back up again.

The things that tend to fail on them is that the Diaphragm in the Sphere will split and then all the pressure of the air from inside the Sphere will get dispersed in the system. With the valve body it’s likely that it will either leak or seize up in there and not hold pressure properly. You can get corrosion because they use the RR363 Brake Fluid which is effectively a DOT4 with a lubricant. It’s hydroscopic so it can get more moisture in there and it can rust the components. It’s always good to change your Brake Fluid at the regular service intervals.

The Rubber Seals here can leak out and you might get a leaking out of this cap in the inside but we will look at that bit more when we get to the break down. The reason why they have the Accumulator is for the pressure reserve, the 1,000 psi of nitrogen is charged in at this end and that allows when the Brake Fluid starts being pumped into the Valve Body, it gives it something to go against so as soon as it starts building up it’s pushing against the Diaphragm in here until it equalises and then goes over the top. That means that when you put your foot on the brake pedal and disperse some of that pressure, if there was no diaphragm with pressure behind it, it would just be dispersed straight away because you can’t compress a liquid. We will talk more about this when we get the components stripped down in front of us. For now, I think that’s the end of this video and please subscribe to catch the next ones and we will do a further breakdown.”

Part NumberDescriptionApplicationPrice (excl. VAT)
RH2343Accumulator Sphere ReconditionedFrom 1965 to 1980 with chassis numbers 01001-26700 £144.50
RH2390Accumulator Sphere ReconditionedFrom 1965 to 1980 with chassis numbers 30000-42000 £144.50
CD6000GMFAccumulator SphereFrom 1965 to 1980 with chassis numbers 50000 onward (mineral fluid cars)£58.10
UE37583Valve Body ReconditionedFrom 1965 to 1980 with chassis numbers 01001-20754 £144.98
UE39519Valve Body ReconditionedFrom 1965 to 1980 with chassis numbers 20754-42000£144.98
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