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 Rear Suspension Spheres
What they're for
The rear spheres act as shock absorbers do on a "normal" car. The difference is that the sphere is a metal ball, inside the top half is filled with Nitrogen gas, then there is a plastic membrane. The bottom of the sphere contains LHM mineral fluid. When the car crosses a bump, the piston in the rear arm is pushed up, this in turn h forces LHM into the sphere. This moves the sphere membrane up against the nitrogen to produce the Damping effect.

Where do I find them?

Undeneath the back of the car at eithr side, mounted on the rear struts horizontally..

Changing the Rear Spheres.

Bad News! This job is not so easy as the front ones, but, its OK. With the car in the High position, and the engine off, jack up both sides of the rear of the car and place 2 axle stands securely under the rear axle tube, lower jack so that the car is supported by the axle stands, and check that all is safe. On no account should you attempt to looosen the spheres in "low" as the strut will twist, fracturing the hydraulic supply pipe! Loosen both rear spheres no more than 1/4 turn using the sphere tool, or a chain wrench. The rear spheres may be "tight" due to corrosion. You can try and loosen them using a cold chisel and a hammer, with geat care, but the proper sphere tool, with gentle taps from a hammer is the best bet. Place the height lever in the Low position, and allow 5 minutes for pressure to release. Remove both spheres using hand pressure anti clockwise. Use rags to mop up any LHM that will spill onto the ground. Remove the old sphere seals from the strut mounts.

Fit new sphere seals into strut opening so that they sit flush, then screw on both new rear spheres usin gjust over hand pressure. Start the car and place lever into High position and check LHM level, top up if required. Move the height lever slowly from High to Low with interval of a minute in between to bleed the system 4 or 5 times. In the case of the rear spheres I also bleed the sytem at the Pressure regulator by opening and closing the 12mm valve 1/4 turn a few times with the car running, and in "high".

Don't forget to check and if required top up the LHM level.

Job Done!