curious suspension problems. Still....

[maxgreenwood]

I'm still having problems with my suspension.

My car drives beautifully ride-wise when 1st started up, ie engine cold, for about 5 or 10 minutes, glides along, absorbs all speed bumps and holes in the road. Just like i think a citroen should. I'm always really into the car at this point. Then the suspension stiffens up and the car kinda gets shaky - not drastically so, but especially on some surfaces the car shakes up and down. And the road makes the interior fittings shake and crack a bit. Not at all like it should be i don't think. And i'm thinking 'this can't be right' It starts to happen exaclty when the engine has warmed up and is idling at 900rpm as opposed to the advance 1,100 or so. The wheels are balanced. The tracking is not quite right but this doesn't explain these differences i don't think.

I mentioned this before on here and was given some good advice from jeremy to grease up the height correctors, which i did, and got some imrovement, but i'm not sure i've done it properly. Do i need to remove the plastic cover and get right in there? How do i do this? I found it very difficult to even see and just kinda squirted grease around it. I would appreciate any extra advice on the best way to get in there.

Some details about the car:
The car has just completed 2000 miles on Hydraflush, taken out and filtered twice in this time as steering was getting heavy and a load of silt was collecting. I'm due to change back to new LHM soon. I've greased the front struts under the gaiters and this makes it very smooth to rise and fall. Tick time is 10-14secs. Acc sphere+front sphere 10 months old, rear spheres a year old. So i think they're all good. Nice and soft when car pushed on corners after its been left for a while engine off. (although much stiffer straight after a run concurrent with symptoms described above)???

It feels like its is stiffening up at the rear as well as the front, so i don't think it is primarily front strut related.

If the ride is great when cold, stiff when warmed up does the problem sound like sticking height correctors?

Please help me Obi Wan CLub.co.uk you're my only hope

[jeremy]

The tick time is a bit rapid. If the accumulator is still OK (yes it should be as its new but you'll waste hours if it isn't - so test it again by the sit-in-the-boot-test) then its probably a defective regulator non-return valve. The good news is that you can repair it for nothing. Remove the accumulator sphere and on its mount fact you'll see a plate secured by a (10mm?) bolt. Remove the bolt and collect the ball bearing under it (it'll probably fall in your eye) and stick it back in the hole with a dab of grease. Now get a brass or similar rod (NOT STEEL) and tap it once only smartly into its seat - then re-assemble.

The theory is that from the accumulator LHM goes onwards - as it should, down the centre piston rod about which you can do little and isn't generally a problem - or back the way it came which is past the one way valve - which is a simple ball bearing seating in the casting. I did the one on my DTR Turbo about 7 years ago and I still can't be bothered to time the tick interval as its so seldom. It was about 10 seconds beforehand.

I have one the job with the regulator on the car - its quite easy under the diesels.

Usual health warning - Make sure the car is properly suspended so that there is room for you should the suspension collapse.

As for the ride - I'd try greasing the height corrector again. I know ts tedious but it worked before - which suggests you're on the right track. You take the thing off and overhaul it which might be best. Try raising the car and then dropping it and seeing if its any better.

After time the height corrector linkage gets stiff and the cars seem to ride best at their intended height. The struts themselves deteriorate again resulting in a stiff ride - I was amazed by the difference new ones made.

[maxgreenwood]

Hi Jeremy, thanks for your in depth advice here and suggestions. I did punch the ball bearing when i changed the acc sphere, although not sure i gave it a square enough or hard enough hit, i then didn't want to try again for fear of creating two overlapping seats for it. Is it safe to try again? I guess it just need to be a bit harder than the last time?

The ride before i squirted around with grease last time had deteriated very badly and it did relieve it but no matter what i do i can never maintain the ride as good as it is when the car is 1st started and the engine is cold.

So whats the best way to get the height corrector(s) off - the front one is buiried.. is it easier to go in from one of the wheels arches with the wheels turned?

Citeraobics don't make any difference to ride, i've ruled out the lubrication factor. Struts seems smooth.

Leaving it in Low overnight gives me a dream ride, but again only until everything warms up.

[ellevie]

I wonder if it could be air getting into the LHM ?

There has been quite a bit of speculation over the years that air or nitrogen bubbles in the LHM could cause a harsh ride. It might be worth checking the LHM in the reservoir for evidence of frothing. A leak on the low pressure side of the pump could admit air, or a slowly failing sphere could release nitrogen into the LHM.

This would explain why leaving it in low overnight cures the problem for a short while because most of the LHM would be returned to the reservoir which would then act as a settling tank overnight.

[DavidRutherford]

I think this could be something to do with the fact that the car is still running on Hydraflush rather than LHM.

After all, in theory, the height correctors should have no effect whatsoever on the suspension softness. They're there to increase or decrease the length of the hydraulic link between the wheels and the spheres, nothing else.

I suspect this may be something to do with the hydraflush changing viscosity as it heats up. If it's been in there now for 2000 miles, get it out and get some fresh LHM in there. If you can afford it, I'd drain the hydraflush out, fill the system with the bare minimum of LHM just so you can flush the worst of the hydraflush out (maybe 2 litres) bleed the brakes, wind the steering and make it go up (even just a tiny bit... no need to go all the way to high) Then dump that LHM and refill with fresh.

When we did this with Adamski's CX the ride was utterly transformed. Hydraflush is a good cleaner, but it's a rubbish suspension fluid.

[DLM]

I'm with David on this: Hydraflush can make hydraulic action very unpredictable until finally swapped out after it's done its good work. At the risk of sounding obvious, what's the fluid level like, too? Do you get a wet finger if you put a finger in the tank at normal height ? If not, then lack of hydraulic fluid may be causing some increased clickage frequency and rougher ride.

Normally ride is rougher when lhm is cold, better once warmed up - I don't know how hydraflush behaves at different temperatures..