Changing Spheres

Given sensible caution, is its very easy to change any of the spheres on your BX without enlisting the help of a garage.

But two very important things

1) System pressure is around 2000psi, and unscrewing a sphere without depressurising the system could result in serious injury or death!

2) A car suddenly depressurising could drop immediately and kill you, the car MUST be supported!

Ok, theres the warnings out of the way. We're now going to show you how to change spheres without injuring yourself and in a short time whilst saving yourself £'s.

The accumulator
What it's for
The accumulator stores system pressure to be used by the Brakes and suspension. It has a gas volume of 62 bar.If the accumulator is "flat" (i.e. as a result of nitrogen gas gradually escaping from it over a period of time) the result is the the Hydraulic Pump must work very hard to maintain system pressure. When this sphere is flat you will here a frequent ticking or clacking as the pressure regulator opens and shuts rapidly. This is very undesirable. The accumulator stores pressure to give the pump an easier life, it also holds a reserve of pressure in case of hydraulic failure, giving some braking and suspension pressure for a short time should the pump fail.
It is therefore vital that a new accumulator is fitted should you here the "clacking" in an interval of less than 15 seconds between clicks. A new accumulator will only allow the regulator to open close maybe every 30 seconds providing that the HP pump is sound.

Where do I find it?

Its a green sphere screwed onto the Pressure Regulator which is mounted on the front of the gearbox bellhousing, behind the radiator.

Changing the Accumulator

Run engine and place height lever into "high" position. Place trolley jack under front subframe, jack up car, them place axle stands under front subframe either side.
Turn off engine and move height lever all the way forward into Low. Then open the 12mm bleed on the pressure regulator 1/2 a turn to release any remaing system pressure. Wait 5 minutes.
Using sphere removal tool loosen accumulator sphere, remove tool and unscrew by hand. Have a bucket handy to catch any split LHM fluid. If you don't have a sphere tool, the accumlator can be tapped loose by using a chisel and hammer to roetate it in an anti-clockwise direction.
Remove the old sphere seal from the regulator and carfully fit the new one provided with the new accumulator so that its flush with the pressure regulator body. Screw on the new accumulator in a clockwise direction. Tighten just over hand pressure.
Start up the car with the height lever in the HIGH position, and open the 12mm bleed valve 1/2 turn, and let engine run for 20 seconds. Tighten valve. Then open and close valve 1/4 turn 10 times, and retighten.Car should now rise to "High" at the back. Remove axle stands, and jack carefully. With car running in high, check LHM level and top up if required.

Our handy Tip!

Some of us have replaced the standard accumulator with a centre front sphere from the XM model. This has greater volume (70 bar instead of 62) and helps if your car has a slightly weak pump.