ZX Volcane Brake Servos and Rear Suspension Parts.

Chlorate · Post by **Chlorate** » 05 May 2010, 22:49

MOT coming up this month, as usual there's a bundle of things that could fail the bugger.

Most concern is the lack of servo assistance on braking (which can be a little hairy to say the least).
Stuck a Mityvac on the pump and found that it was pulling the right vacuum, so by process of elimination either the servo has gone or the valve on it has.
Not easy to test either because of all kinds of nonsense in the way, and couldn't get a good enough seal on the vac hose with the mityvac.
Looking at servos on ebay, I know that a lot of parts on the ZX are identical to various other cars, I think I can be safe looking at servos from:
Pug 306, Citroen Xsara and possibly the Citroen Berlingo.
Although I suspect that I could get away with taking parts from a lot of non-hydraulic Citroens and a fair few older Peugeots.
If anyone could confirm some of those compatibilities or add to them that'd be great. Relevant part numbers on the servo would be helpful too.

Other concern is the rear axle, had a bump noise coming from the back of the car for a while now which turns out to be one of the trailing arm bearings.
With any luck it'll slide through the MOT unnoticed (haha...). But I've been looking up prices of replacement assemblies just in case.
My only worry about this though is that it's a Volcane, so I suspect that the struts and torsion bars may be different (or set up differently) from your garden variety ZX.
Struts look relatively simple to replace (although 3 out of 5 spanners in my experience usually means near impossible) but the torsion bars require a tool from Citroen.
Again it would be most appreciated if anyone could shed some more light on this.

Thanks in advance if anyone can help me. With any luck I can get my little work horse through the test and it'll keep me moving for at least another year.

-Alex

citroenxm · Post by **citroenxm** » 06 May 2010, 10:09

Wouldn't the bump be more like the subframe mounts deteriated??

I had a 306 that banged badly on pot holes, but MOT could not find a single problem..

As for a servo, Ive got a 306 Servo spare, bought for my Mums 1996 306 TD years ago due to poor servo suction.. and crap brakes, however, it was never used, and the car always passed the brake test.. the servo assistance was crap though... were as my high milage 306 had a much better assitence!

Paul

citronut · Post by **citronut** » 06 May 2010, 13:02

as Paul says the bumps and bangs at the rear of a ZX are usualy sub frame mounts, the first ones to show are the rear rear mounts and are very very easy to change, the front rear mount dont go as offten and are a little harder to change,

for the MOT if your rear axle/suspension has still got movement in the arm's, and the rear wheels arent leanning in touching the inner wings they cant fail it/them,

if your rear axle/trailing arms are shot ther usual fix is fit a good replacement copmplete axle, as more offten than not the arms will have chewed up the axle tube they swing on,

i presume by struts you mean the rear shockers, these will only need replaceing if the rear suspension bounce's all over the place when going over bumps in the road,

regards malcolm

Chlorate · Post by **Chlorate** » 06 May 2010, 17:06

Hmm..then maybe the rear axle isn't so much of a worry after all.

What I meant about the struts is are they different on the Volcane models, i.e. is the rear suspension firmer or lower on a Volcane than the usual ZX and would I have to swap the struts or torsion bars or both over from the assembly I have in order to keep the same ride?

-Alex

handyman · Post by **handyman** » 07 May 2010, 10:33

Much of the suspension system is the same throughout the ZX range and is also used in many other PSA applications, Xsara, 309, 306, 206, etc.

The only real variations on the top range models, Volcane and Aura are thicker torsion bars, both front and rear. The weight on the back-end of most of these PSA cars are very similar and I do not think PSA went to the trouble of designing individual spring rates for the whole range.

Now the front end is a whole different matter for spring rates, as the petrol engined cars are featherweights in comparison to the heavy, smelly diesel donkey!

You can use the later gas-powered rear shocks from any of the PSA range, save estates, as the damping rates are similar. Worth checking stroke and compression lengths. Some mountings are different but can modified safely. There are no struts on the back of any Zxs or similar vehicles in the PSA range.

Currently, my ZX is running around on later 206 front and rear shocks, with no detriment to performance.

H