Weird Suspension Behaviour

[Peter.N.]

My son is currently using the green estate for work as his truck is off the road. He was away for a few days leaving it parked up outside in all that freezing weather, when he came to use it on Monday he complained that the suspension felt solid, although at normal height, rubbish, impossible I said and went outside and checked it, three corners were going up and down OK but the o/s rear was indeed solid. As it was at normal height I thought the only possible problem could be a failed sphere, the height corrector was obviously functioning so there should be fluid moving in and out of the sphere. When he drove it home again he said it was now OK, he came here this morning and lo and behold the o/s suspension is moving normally. Other than water in the spheres, I can't think of any rational explanation for this syndrome. Can you?

Peter.N.

[Citroenmad]

Sounds like its got a sticking strut, thats probably the cause, especially since it had been stood and after some driving its working again.

[Peter.N.]

Don't think so, when started, suspension comes up to normal height, just no movement in it.

[Citroenmad]

That is an odd one then, but it comes ok when its driven for a while?

[Peter.N.]

I think it came OK when it got warm - as if there was water in the spheres!

[Dieselman]

Possibly, in which case whip the sphere off and drain it otherwise any ice that forms could damage the diaphragm.
Don't forget LHM isn't hygroscopic like brake fluid so doesn't draw any water away from components, it just sits there.

[Peter.N.]

According to my son it happened to all four! he said the suspension was absolubtly solid when he first drove it, by the time he got to me, about three miles, and it had stood for half an hour or so, only one was still solid and he said it was fine when he drove it home. Could you get that much water in LHM?

[Dieselman]

I'm not sure how much water could migtate into the LHM past seals, etc but think the senario fits. Water ingress is the reason why brake calipers corrode and sieze.

I think the small damper orifices possibly froze causing lack of fluid movement and thawed out due to engine and exhaust heat, which is why the o/s rear was last to thaw.

Did you check the car was at the correct ride height and that it actually rose and fell on demand from either starting or adjusting the height.?

[Peter.N.]

By the time I saw the car it was only solid on the o/s rear, as you suggest, the furthest one from a heat source, and yes, the suspension was definitly going up and down with the ride height lever, just that there was no movement on the suspension itself.