Sump'thing and nothing

mpr1956 · Post by **mpr1956** » 01 May 2005, 14:58

Not sure what you did wrong... I did my acc recently more or less as you did and car dropped steadily... ( kind of reminds everyone about safety though, doesn't it ? -talk about no second chances ! )

mpr1956 · Post by **mpr1956** » 01 May 2005, 14:59

ps.. I've got a 93 tdsx, so no anti-sink..

Post by **RichardW** » 01 May 2005, 15:28

When you put the car in low, the height correctors open and the pressure is removed from the suspension. However, since there is nothing pushing the wheels up they stay hanging in the air. For reasons I don't understand, when you re-start the engine and put it in high, the suspension doesn't repressurise, hence the falling flat you got. Secret is to jack it off the axle stands, then lower it so the wheels are touching the ground and the the height corrector is woken up, then stop lowering and wait for the car to lift itself off the jack - without crunching the sump.

citronut · Post by **citronut** » 01 May 2005, 16:52

hi superloopy if you take the weight of a hydraulic citroen susp it de/presurizes usuly front end only but it either end are of ground with presure releast they done re/presurize untill weight back on sup some times xatias if rear end of ground with presure releast front end on ground when you put back on high before lowering rear to ground front comes back up then when you lower rear end it sinks right down then you have to lower front end to get it to rise fully ,you might of let your jack down to quick because you thout supsp was fully up when there was no presure in front system regards malcolm

oilyspanner · Post by **oilyspanner** » 01 May 2005, 17:52

I love the way they follow the jack all the way down then sit on it, its one of their endearing traits, especially when the engine is dead and there is no pressure to raise the thing again[}:)]
Stewart

ActivaV6uk · Post by **ActivaV6uk** » 01 May 2005, 18:36

You have to remeber when there is no weight on a strut the sphere will be "un stressed" so when you do put weight on the srtut the diafram in the sphere moves and the suspension falls.
The only other thing it could have been is air in the system.
Andy

citronut · Post by **citronut** » 01 May 2005, 19:08

when no weight on stuts they will not presurise at all apart from rears

AndersDK · Post by **AndersDK** » 01 May 2005, 21:38

It can never be repeated too many times :
Working on hydro Citroen suspension is a dangerous task - especially for the first timer.

Post by **Peter.N.** » 01 May 2005, 22:32

Apologies if I am repeating something someone has allready said, but , if you raise the suspension manually i.e. by jacking the car up, the height control valve thinks, (quite naturally) that the suspension is to high and therefore lets some fluid out, hence the rapid descent.

Post by **Peter.N.** » 01 May 2005, 23:40

If the engine had been running and the system was pressurised, yes, but they sometimes take a while to come back when you have depressurised them. If you put the suspension on full height prior to depressurising, it will very often stay up as in this position the height corrector is overidden by the height selector

Post by **Peter.N.** » 01 May 2005, 23:49

I just noticed the second part of your question. I live on quite a steep hill and also in the country, so what I have done is leveled the ground by the side of my garage and built a retaining wall about the height of a 45 gall oil drum. I have levelled the ground behind so that I can drive up to the top of the wall and have two thick planks of wood, supported by two oil drums onto which I can drive the car. I did this about 30 years ago and still have the same timbers in place! and they support my XM estate OK. This is just the right height for working on brakes, suspension etc and allows easy access to the underneath.