Couple of questions
I have a 1998 Xantia 2.1D Exclusive with hydractive. (Replacement for the much loved BX) It feels to me as if it is ready for a new set of spheres not unexpected after 5 years and 120k miles. Looking through the service record it lools like only the accumulator has been changed.
So far I've spotted 7 spheres (4 strut, 1 rear anti sink, 1 rear hydractive, 1 accumulator. Can anyone confirm that it will have a front hydractive as well?
Assuming sphere degeneration is a function of time as well as use, is it likely that the hydractive spheres will need doing as well as the 4 strut spheres? (I am assuming the that anti sink sphere is fine as the car stays up for more than a week.)
Regards
Rory
Spheres - 2 questions
Moderator: RichardW
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rory_perrett
- Posts: 715
- Joined: 05 Nov 2001, 19:18
- Location: Leeds, Yorkshire
- My Cars: Xantia Exclusive 110Hdi Estate 1999
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Rory -
You're right assuming the sphere's life are time dependent, but not usage dependent. This is because the inherent N-gas/rubber membrane diffusion problem, which is independent of usage. Even new spheres on stock are slowly loosing the pressure because of this.
I'd say you replace the spheres which are flat. Do'nt go for all "just to be sure". Sphere's replacement are not complicated and therefore not highly garage expensive.
It's simple to test your 4 wheels suspension spheres :
Have engine idle, apply handbrake, car in normal driveheight.
Press down each corner of the car.
It should be fairly easy to press down the front corners approx 1 inch, the rear corners approx 2 inches. If it feels rock hard, i.e. if only tyres/rubber stops seems to provide any "softness", the spheres are flat.
Allways replace both (2) spheres on same axle, like you would replace dampers on a "normal" car.
You're right assuming the sphere's life are time dependent, but not usage dependent. This is because the inherent N-gas/rubber membrane diffusion problem, which is independent of usage. Even new spheres on stock are slowly loosing the pressure because of this.
I'd say you replace the spheres which are flat. Do'nt go for all "just to be sure". Sphere's replacement are not complicated and therefore not highly garage expensive.
It's simple to test your 4 wheels suspension spheres :
Have engine idle, apply handbrake, car in normal driveheight.
Press down each corner of the car.
It should be fairly easy to press down the front corners approx 1 inch, the rear corners approx 2 inches. If it feels rock hard, i.e. if only tyres/rubber stops seems to provide any "softness", the spheres are flat.
Allways replace both (2) spheres on same axle, like you would replace dampers on a "normal" car.
The function of the anti-sink sphere is not quite what you expect. In fact the anti-sink function is controlled by the valve and the sphere simply tops up the pressure primarily for the brakes when the valve opens and before the pump has restored pressure. The effect therefore of a failed sphere is that after the car has been standing for a long time the back of the car will drop when you move off as well as poor back brakes.
jeremy
jeremy