Height Corrector cleaning and overhaul
You will need:
- x3 Front Height Corrector Hydraulic Union Seals (Citroen part number - 96 085 785)
- 8mm flare nut spanner (an open end spanner will round the delicate unions)
- Spanner Set
- Screwdrivers of varying lengths
- White grease spray
I will abbreviate height corrector to 'HC'
Secure the front of the car on axle stands and block the rear wheels, best to get the front wheels a good few inches off the ground with the rams on full length for access.
De-pressurise the suspension by setting the manual height control lever to low while the car is running and letting it settle.
De-pressurise the accumulator sphere by turning the release valve, the 12mm bolt (blue arrow in photo) on the sphere block on the front of the engine, no more than half a turn, a hissing noise may be heard.
Be certain the car is secure on the stands.
Remove the 'R' clip which secures the manual height control lever to the manual height control rod and slip it off the control lever.
Unscrew the two bolts that connects the height corrector cradle to the sub frame, this will give you a bit of flexibility when disconnecting the linkages.
Using a suitable implement, take the pressure off of the plastic anti-roll bar to HC clip by manipulating the bottom plate from the NS spring
and use a screwdriver or pliers to pop off the plastic clip from the metal anti roll bar rod. Another way of doing this would be to slacken the anti roll bar metal link and pop off the plastic link but then you would need to reset Xantia ride height.
Now for removing the manual height control on the OS spring. This is directly touching the spring so it is a case of pulling the height control rod towards the rear of the car and moving the front end of the spring out of its locating dip on the HCR, the other part of the spring can then be slipped out by manipulating the HCR. It may help to loosen the bolt on the HCR to ‘Socket Tool’ (according to Service Citroen) but it would be worth marking exactly where it bolted to as this can be used to vary the length of the HC rod.
Loosen the three hydraulic unions then undo them one by one before blocking the ends with suitable tissue to prevent any swarf getting into the pipe or height corrector. It may help to unclip the pipes from the plastic holding channel. Make a note of which pipe goes where, on mine, the one with the largest angle is for the union towards the rear of the car.
Pull off the leak off pipe from the top NS of the HC and block with tissue as above.
Now it comes to removing the HC from the car (Bearing in mind that I’m dealing with a car with no semi or fully active suspension). After a bit of fiddling about, I found the best way to be sure that the pipes were either clipped back into the plastic channel or moved carefully out of the way, the HCR also needs to be moved to one side. The HC needs to be moved to the OS an inch or two then the front of the HC needs to continue moving to the OS just enough for the rear of the HC to move towards the NS a touch to drop down. The rest of the HC should then follow; failing that a bit of wiggling should do the trick.
Remove the two bolts underneath the HC
Using a small pair of pliers remove the hydraulic pipe seals from the HC, afterwards renew the tissue.
Now your preferred cleaning method of the linkage, soaking overnight in a tank of diesel, painting with a small brush and diesel or other cleaner until all is clean. Check that the springs move smoothly as you may notice there are still bits of swarf in behind them. A bit of spring moving should get it out along with the small brush.
Using the white grease spray, lubricate all of the moving parts and manipulate them.
Move the height corrector back into the cradle and screw the bolts back in.
The HC+Cradle unit fits back in using the method of removal
Firstly, remove the tissue from the hydraulic and leak off pipes, slipping the new seals onto them so that they are all the way on the pipe. Fit the pipes back into their correct hole and loosely screw them in with the flare nut spanner. Be sure not to use too much pressure as the thread in the alloy body is easily cross threaded and the union bolt is prone to slipping off the spanner if it is not exactly the right size. This is where a small pair of mole grips come in handy (Yes, I’m talking from experience :oops: )
The rest is a reverse of removal bearing in mind these points.
When all the HC and cradle linkages and bolts are connected, tighten up the unions (though as said, not too tight)
If you did loosen the control rod to ‘socket tool’ bolt, set this back up to the correct length again, if this is slightly out, you will notice the HCL will be difficult to move to either service high or service low.
If you loosened the anti roll bar clamp, the ride height will need to be reset. For this, you will ideally need a lift, pit or wheel ramps if you’re brave enough!
Before packing all your tools away, test out the suspension.
After all the tinkering with the height control system, you should find that things click into place and you know roughly the root problem of symptoms.