7.1.1 - Brake Accumulator Replacement ( ,  )

The replacement of the accumulator on the 3.6 litre XJ40 can be very easy or very difficult - just the luck of the draw. It is absolutely essential to completely depressurise the system before attempting this replacement, as releasing high pressure oil can be very dangerous.

If the entire accumulator assembly is removed from the car, the only hard part is getting the hydraulic connections back on and not cross-threaded. Make a clear note of how far the connections screwed in, to be certain if they are cross threaded or not on replacement before using a spanner. Also, if the clamp around the accumulator (that holds the assembly on the car) is attached but left loose until the connections are almost fully tightened, it can make the job easier.

Another caution is in unscrewing the old accumulator from the aluminium block and screwing on the new one. Using a spanner is not a good idea. It is much better to clamp very lightly in a vice with wood blocks and use a filter wrench. The accumulator does not need to be over tightened. It seals with an 'O' ring and cannot undo when in place.

Some mention has been made of the electrical block connectors. Having fiddled with these on several occasions, they are very simple to dismantle after the first time. The pins each have a small nib that springs outward when the pins are in place and stops them from pushing back. After fishing out the seals from inside the plug, this nib is accessible and can be bent back in with a very small screwdriver or similar. Before re-assembling, it is necessary to bend them back out.