Rock hard suspension at the front

MULLEY · Post by **MULLEY** » Wed Mar 18, 2009 8:14 pm

Mechanic fitted some new handbrake cables, he had the suspension on the highest setting whilst doing the job. When i collected the car, i noticed straightaway that the front suspension was quite pogoey.

I've checked the ride height, it looks fine from front to rear. Pushed the suspension down by hand at the back & this was fine, nice & soft & went up as normal.

The front is pretty rigid, pushing down on the front, it does move a bit, but its very hard compared to what it was like before (both sides).

I tried some citreobics, no change in the firmness at the front.

I had wondered whether it might be one of the following:

1) Front height corrector knocked/altered by mistake.

2) Front height corrector gunged up.

3) Front height corrector seized.

4) Front spheres suddenly gone flat (unlikely as i thought that would
be gradual?).

If its not one of the above, anyone got any other ideas please?

Way2go · Post by **Way2go** » Thu Mar 19, 2009 1:29 am

If the ride is hard and pogoey with struts at normal ride height then your spheres are shot.

MULLEY · Post by **MULLEY** » Thu Mar 19, 2009 1:05 pm

Can this literally happen in a day? i thought they would gradually lose pressure & go firmer. I guess if they can, then i've got some spares which i can fit to see if that is the case.

jonathan_dyane · Post by **jonathan_dyane** » Thu Mar 19, 2009 3:15 pm

Sometimes they do rupture...

Seeing as you have a spare (known good?) pair, it's probably worth popping them on first, before you get more involved.

Way2go · Post by **Way2go** » Thu Mar 19, 2009 3:39 pm

Basically, the height corrector does what it 'says on the tin', it controls the ride height which is totally separate from 'springing and shock absorbing' which is the province of the sphere.

IMHO if the ride is harsh and pogoey and it's not the sphere then the only other (unlikely) culprit could be that your struts are mechanically seized.

DLM · Post by **DLM** » Thu Mar 19, 2009 6:01 pm

Have you tried any Citaeoribics since - from very top height back down to lowest and then back again a number of times? If there's stiffness as a result of the struts sticking - particularly likely if a car hasn't been used much or not for a while - then this may have an effect.

After that, if the front's still stiff and there's no other clue, then I'd agree on spheres. When changing spheres, put a plastic bag around the spheres after the inital "crack" to loosen them, when you start to unscrew them by hand.

Why? Because ruptured spheres bleed their nitrogen into the lhm, which can make for plenty of green lemonade when you remove them....

velosolex50 · Post by **velosolex50** » Thu Mar 19, 2009 8:39 pm

Why would the spheres fail suddenly? Perhaps the car was left at full height thus with full pump pressure to the spheres for too long. The unaccustomed high pressure could have deflected the sphere diaphragms way beyond normal & cracked/split them, allowing the nitrogen to bleed out. Just a theory, but I can't think of any other cause for the symptoms other than failed spheres. Could you borrow a good pair to switch over? It must be the least difficult job on the BX. Good luck!
Huw

MULLEY · Post by **MULLEY** » Thu Mar 19, 2009 9:26 pm

Struts are fine, no stickyness. Sounds like perhaps they've ruptured, didnt even realise this was possible

Luckily i've got some spare ones i can fit, so will try that to see if it cures the problem.

I've already dropped the suspension to reduce the pressure, hopefully they wont spurt out too much lhm when taking off the green bombs. I normally just put a rag underneath to catch the dribble.

Once done i'll report back my findings.

Is it normal for both spheres to rupture at the same time? I did check by pushing down on both sides, & both were stiff (oooh er

)

I'll check with mechanic to see how long he left the car up on high, is there a recommended time limit? I also thought that once the engine is switched off, although the car is still on high the actual pressure in the system whilst still high, wasnt as much as with the engine running.

Cheers for your thoughts so far chaps.....

citroen7 · Post by **citroen7** » Thu Mar 19, 2009 10:12 pm

Mulley,
can you just clarify a few things,
1.does the suspension travel from normal to low and then back up high
or does the back go up and down but the front stays put?
2. is the lever inside the car difficult to move through the settings especially from normal too high
one thing i will point out is that the height correctors are an integral part of the system they do not just raise and lower the car i would bet that in all probability that in replacing the handbrake cables something has been put out of aligement causing the height corrector linkages to sieze up , its easy done!
Past experianence has taught me that if something is not working after some other work has been carried out that is the point to start looking

MULLEY · Post by **MULLEY** » Thu Mar 19, 2009 11:18 pm

1) The front & back go up & down as normal, although admittedly the front sometimes seems a bit stuck in low, a few citreobics normally gets it to rise again though. That would either imply the linkages are a bit seized or that the height corrector is gunged up. However, these shouldnt affect the springiness of the suspension when its at the correct height?

2) No

I'm still thinking that its the spheres, based on what way2go said.

ken newbold · Post by **ken newbold** » Thu Mar 19, 2009 11:45 pm

If you have some spare ones, just swap em over and find out! it'll only take you 2 mins

mnde · Post by **mnde** » Fri Mar 20, 2009 1:29 pm

DLM wrote:When changing spheres, put a plastic bag around the spheres after the inital "crack" to loosen them, when you start to unscrew them by hand.

Why? Because ruptured spheres bleed their nitrogen into the lhm, which can make for plenty of green lemonade when you remove them....

I know this very well... Changing the front spheres on ren16tx's maroon lhd MK1 19TRD a couple years ago was a scene straight out of a operating theatre in Casualty. I carefully undid the first sphere - lots of LHM seepage as I went, which was mopped up with pre-placed kitchen roll... then when I lifted the sphere clear... WOAH! a sudden strong jet of LHM spurted from the bottom, coating the underside of the bonnet, then, as I reacted in surprise, my glasses, then it got Chris in the face; finally I aimed it into the next door garden. We were in hysterics

Mark.

MULLEY · Post by **MULLEY** » Fri Mar 20, 2009 6:54 pm

Luckily that didnt happen to me

Left on low overnight so the pressure was low, undid them, the usual small amount of lhm dribble, fitted some replacement spheres.

Hurrah, suspension works fine again.

I'm still bemused why both spheres would have gone flat/ruptured. Spoke to mechanic, he said he only had it on high for about 30 seconds.

velosolex50 · Post by **velosolex50** » Fri Mar 20, 2009 9:58 pm

Glad simply fixed. Interesting lesson for us all
Huw