Height Correctors

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Post by myglaren » 06 Jun 2010, 22:02

As always, prior to starting any work that involves getting underneath a Xantia, or any Citroen with hydraulic suspension, make absolutely certain that the car is firmly supported on axle stands or ramps. This is particularly important when working on the suspension system hydraulics, the car can drop very suddenly with fatal results.

This document describes the methods and tools required to address the repair or refurbish Xantia height corrector problems.

original thread location


Tools:
Axle stands.
x3 Front Height Corrector Hydraulic Union Seals (Citroen P/N - 96085 785)
Purpose made 8mm flare nut spanner (an open end spanner will round the delicate unions!)
Spanner Set
Screwdrivers of varying lengths
Pliers
Mole Grips
White grease spray.


Removing:

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 bolt 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 100% secure on the stands!

Remove the R clip which secures the manual height control lever to the manual height control rod and slip 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.

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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

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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 the height would have to reset using the table in the following link (link)*Link missing in original document!

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 HCR.

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.

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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. I hope that description was clear enough as the photos I took under the car didn’t come out very clear.

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Cleaning the Height Corrector:

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Remove the two bolts underneath the HC.


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Using a small pair of pliers remove the hydraulic pipe seals from the HC, afterwards renew the tissue.

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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.


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Using the white grease spray, lubricate all of the moving parts and manipulate them.

Move the HC back into the cradle and screw the bolts back in.

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Refitting the HC

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)

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, you 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.
Some extra notes for the rear Height Corrector.

A LOT easier than the front HC
Three Torx bolts holding the linkage onto the car, two facing the rear, one facing the N/S.
Undo the bolts holding the actual HC on, leaving the hydraulic pipework plumbed in, taking note of the adjustment of the actual HC onto the linkage.
Unclip the plastic clip and manual height control rod.
Wiggle linkage out, one pipe is in the way but after a bit of puzzle solving the linkage can be removed without mucking about removing the hydraulic side of things. Clean HC as in the original posting.
No need to loosen the anti roll bar clamp. Its VERY unlikely to have come out of adjustment.

The rear height can be adjusted by moving the actual HC on the bolts connecting to the linkage.
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Original document by Red Dwarfers.

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One problem that can preclude the correct ride height being attainable is a hairline crack in the plastic “dog bone” link.


It WILL NOT be the height corrector itself, but the stupid linkage that controls the anti roll bar movement to height controller – there are TWO moving levers on the linkage and these are MOST VERY LIKELY to have seized SOLID, so that when the anti roll bar moves with the back end of the car, the linkage can't, so the clip has to pop off - IN WORSE case with a new clip without freeing them up, in which is BEST done off the car, the next part to break can be the anti roll bar clamp! Ive had a few snap now..

Not sure of your mechanical abilities, but DO get the linkage off, remove the height controller, by the two 11mm nuts you can see facing you when looking up, you can either LEAVE the 3 pipes connected or remove them. TAKE note to how the height corrector is linked into the levers!

The linkage unit is attached by 3 Torx head bolts, two facing the rear, and one to the side, look at the structure of the unit and you should find them.. I've no picture for position reference for you..

The two levers should be nice and free to move..
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contribution: citroenxm
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You beat me to it Paul as i was going to say similar, apart from i call the two levers turrets, and i do agree you cant free them up long term whilst in situ,

Even with them off the car they take a lot of working lubing working lubing working lubing working lubing working lubing.

To free them off properly so the two turrets are very floppy loose.

Other that that Martin at Pleiades* does re/con brackets for a reasonable price.

*Pleiades
Unit 12A Brookside Industrial Estate
Sawtry
PE28 5SB

Tel 01487 831239


Contribution: citronut

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Here are pictures of the newly pivoted front and rear height corrector linkages. Used turned down M14 bolts with a 3cm shank, tapered one end and tapped it in the increased sized hole where the rivet used to be.

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original post by Red Dwarfers

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It's quite normal with a seized height corrector to be able to do both extremes as the manual height control acts on a different part of the mechanism.

Here's a diagram of both front and rear correctors:

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Also, if the corrector is seized, the ride may be less than good. Spheres also may be past their best.

The tick you have heard about is the interval between the pressure regulator cutting in and out like a thermostat to regulate the main system hydraulic pressure. A short tick rate (less then 30s) normally indicates a tired accumulator sphere or a heavy internal leak.

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Contribution – Citrojim.
0x
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Steve

Jackie Evancho