|1983 Corniche drophead (C) JE Robison|
|RR363 fluid reservoir as used from 1966-1980. Note warning label and style - a simple steel container, normally painted silver as shown. Windows to check fluid level are visible on the side.|
|Mineral oil reservoir (and fill bottle) from a post 1980-Rolls (1995 shown) Style varies by model year but colored warning and symbols are the same. Floats to indicate fluid level via a green dot are visible atop the reservoirs.|
The fluid in these systems should be changed annually. Some owners question the need for this, when their cars are rarely driven. Here's why it needs to be done: The hydraulic pumps deliver fluid to accumulators where they compress nitrogen gas under very high pressure. The fluid is separated from the nitrogen by a rubber barrier, but it is inevitable that some nitrogen will make its way into the fluid. This forms bubbles, and bubbles in the fluid cause the brakes to pull and act erratically.
Any car that has been sitting a long time is sure to have "funny feeling" brakes for this reason The cure: Change the fluid annually.
You want the car to endure 20+ pumps without either light coming on. That indicates a system with sufficient charge to provide a margin of safety in braking, particularly if the engine stalls at highway speed or on a hill. If you do not get to 20 pumps before seeing a lamp, in each case, the repair needed would be to replace (Spur) or rebuild (Shadow) the accumulators and overhaul the valve bodies. After that the system would be bled.
** MAKE SURE THE CAR IS IN A SAFE PLACE FOR THE NEXT TEST. It may lunge and roll when put into gear. Be sure nothing is at risk for damage or impact **
Now, while holding the pedal down at the 20th or 21st press, start the engine. Immediately pop the car into gear - get it in gear within a second or so of starting. What does the car do? If it lurches forward and then stops in a few seconds as the brakes grab, there is a problem in the warning circuit. If the car holds firm and does not move the brakes and the warning lamps are ok, and it's good.
If the car holds 21 pumps the brake accumulators should be good for a few more seasons. Brand new accumulators may hold 40 or more pumps but any number in that range is safe. If you want to know the exact count, run the car till the lights go out, give it a few more minutes, and slowly pump till both lights illuminate. Usually one will come on followed by the other.
Look at the rubber hoses to see if they are original. If your car is more than 10-15 years old I suggest you replace all rubber hoses as they can swell inside, creating invisible failures. A swollen hose may cause brakes to drag and overheat. Old hoses are also prone to bursting.
|Original Shadow-era brake hoses, overdue for change (C) JE Robison|
|New style lines and hoses in a restored Shadow (C) JE Robison|
If you liked this story, please leave a comment. And if you want more . . . here are some of my other RR/B essays
Thoughts on buying a used Rolls Royce or Bentley - applies to Silver Cloud and newer series cars
More thoughts on Spur - Spirit - Turbo era car buying
Thoughts on restoration - applies to all cars
Evolution of the RR/B models - Silver Shadow through Arnage/Seraph - original article from the Robison Service website
Inspecting a Rolls Royce or Bentley - Applies to Corniche, Continental, Azure, Turbo R, Mulsanne, Eight, Turbo R, Silver Spur, Silver Dawn, Silver Spirit
More Things to Look For in a 1981-2000 Rolls Royce or Bentley - this is the original article from the Robison Service website
The last Crewe built Rolls Royce convertibles - applies to 2000-2002 final Series Corniche
Repairing convertible top hydraulics - Applies to 1996-2004 Rolls Royce and Bentley Corniche and Azure cars
Head gasket failures in Bentley Turbo cars - applies to Turbo R, Continental R and T, Azure, Arnage
Checking engines after head gasket failure - Applies to all cars
Checking and inspecting Rolls Royce hydraulic systems - all cars after Silver Cloud and print to Silver Seraph. Applies to all Shadow/Spur era vehicles
Case Study - brake failure in a Shadow - Silver Shadow era cars with RR363
Rear suspension gas springs - Applies to all 1981 - 1999 cars prior to Silver Seraph
Changing batteries in seat and ECUs, Applies to 1980s-1990s Silver Spirit / Silver Spur / Mulsanne /Eight / Turbo R
Changing alarm ECU batteries, Applies to 1980s-1990s Silver Spirit / Silver Spur / Mulsanne /Eight / Turbo R
Servicing Shadow and Spur series brakes - applies to 1966 - 1999 cars after Silver Cloud and prior to Silver Seraph
Alcon racing brakes for Continental and Azure - Applies to all 1990s cars but most particularly to the final series Azure, which had these brakes fitted at the factory - a unique variant
Fixing Power Steering Leaks - applies to 90s cars with the reservoir above the alternator
Questions and answers on collector car storage - Applies to all cars
Evaluating paint - Applies to all cars
Robison Service has provided independent service, repair, and restoration for Rolls Royce and Bentley owners all over New England for over 25 years. Our company is an authorized Bosch Car Service Center. We also service Mercedes, Jaguar, Land Rover, Porsche, and MINI motorcars. We have flatbed transport throughout the region. We also offer local pickup and delivery for cars in Springfield, Wilbraham, Longmeadow, Agawam, Westfield, Northampton, and Amherst.