C5 Mk3 suspension reservoir overflowed & car won't rise

[citroen since 1973]

Hi everyone, after 6 months of normal use, after some of the hydraulic pipework was replaced near to the steering rack, my son now has another problem with my old C5 I gifted to him. Over last weekend he started the car up and noticed that the suspension didn't rise. He now lives 50 miles from me (and the indy garage that maintains the car), but I was popping down to do some work on his house yesterday, so had a quick look for a problem. There was no oil on the drive, which looked good, but the suspension would not rise when started. Upon opening the bonnet it was clear to see that there was fluid on top and around the reservoir, which looked like it was leaking from the cap. When removing the cap, it was full to the brim i.e. overfull, which it certainly hadn't been previously. Also, we don't recall hearing the normal sound of the suspension rising, when unlocking the car and starting it.
So, any ideas please? Also, is it possible to drive the car slowly (safely) in order to get it the garage?

[GiveMeABreak]

If the reservoir has been filled up with the car suspension at normal ride height, then the tank has been over-filled. As you probably know it must only be checked and filled between the marks on the lowest suspension setting.

If this has been overfilled, then it may have overpressurised the system and the electro pump may have blown a fuse due to over heating. I'd start be removing some excess LDS first, but be wary if you lower the suspension you may not be able to lift the car again until the issue is resolved. Then check the fuses.

[citroen since 1973]

Thanks Mark. It does seem quite strange to me, as the system, when last checked, was filled to the correct level mark. I'm afraid that the suspension is literally on the floor! No garage that my son tried could look at the car in the short term, in Worcester, so he very carefully drove it back to Telford late last night, when the road were clear. The indy garage he uses loves the car, but does admit that he is quite inexperienced with the model and the suspension. However, he is very keen, very honest and a great mechanic.

[citroen since 1973]

A little update - I spoke to the indy garage today and basically, he doesn't know what's wrong with my sons car! He says that the fuses protecting the pump are okay, but there appears to be no power supply going to the pump. I repeated the info I'd gleened from this forum, that overflowing fluid can quickly wreak the pump, but he just repeated that he thinks that it's a power supply issue and that he has no access to wiring diagrams for the car supsension system. He's now waiting for a colleague recommended mechanic, more aquainted with French cars, to have a look at it, but not until May! Modern cars - maybe we should all go back to bicyles!!!

[Gibbo2286]

Did the master fuses get checked i.e. the ones under the under bonnet fuse board?

There are three wires to the pump two thick, a supply and earth and a thin signal wire, if you can get access to them (open the loom where it goes down at the front corner) and run a wire from the battery + to the pump + i.e. by-pass the usual run then apply 12v to the signal wire, needles pushed though the insulation will give to access for temporary connections, the pump will work if it's not faulty.

[GiveMeABreak]

I just hope by driving it on the floor that it has not caused damage to the system. It should be transported on a flat bed if the suspension has bottomed out, unless you can temporarily get a power connection to the pump long enough to get some pressurisation in the system. That may be enough for a careful drive at slow speeds as the pump normally only intermittently operates to maintain the ride height on these.

[Clogzz]

The pump fuse is number 8 ... 40 Amps.

[Gibbo2286]

I just hope by driving it on the floor that it has not caused damage to the system. It should be transported on a flat bed if the suspension has bottomed out, unless you can temporarily get a power connection to the pump long enough to get some pressurisation in the system. That may be enough for a careful drive at slow speeds as the pump normally only intermittently operates to maintain the ride height on these.

I tried driving one only a couple of hundred yards and found it pretty unpleasant and bottoming out at the least bump in the road.

[citroen since 1973]

Thanks very much guys for your help and advice. I'll pass this on to the garage and report back.

I take your point about the driving it on the floor. Fingers crossed!!!

[citroen since 1973]

The indy garage has thanked me (YOU) very much for the additional information you provided. Thanks once again, Paul.

[Hell Razor5543]

Recently MY C5 threw me a 'suspension fault' wobbly. I eventually found that, although all of the fuses were fine, enough tarnish had built up on the fuse blades to stop the pump working (no power). I cleaned all of the fuse blades in the engine bay fuse box with an abrasive rubber block, sprayed contact cleaner into each fuse socket, and that sorted out the problem. In order to keep the electronics 'happy' I went through the BSi reset procedure, and cleaned the fuses while the battery was disconnected.

[citroen since 1973]

Good points, thanks James. Not sure I can answer your paranoid question though!

[citroen since 1973]

Further update - thanks to the help you have all given us, the indy garage realised that he had missed, what sound like, the master fuse. It now keeps blowing the fuse and it's been decided that the pump is wrecked. Costs to fix a new pump range from £700 for a second hand one, to £1700, for a new Citroen one. The car is now 14 years old, with little retail value, unfortunately it may be time to think of a replacement as it's cost my son quite a lot of money over the past 12 months.

[GiveMeABreak]

These can be taken apart and cleaned up. If LDS fluid has leaked into the pump casing along the seam it can mix with the carbon dust and cause a thick black paste that then shorts out the pump and blows the fuse.

Have a look at this post with pictures of a clean up. This is for a MK I/ II, but the principle is the same as far as the pump is concerned. Look at the article first as it will give you a good idea of issue.

viewtopic.php?p=423599#p423599

and here is a video of the full dismantling (just for reference but no need to go this far for a clean up)

[citroen since 1973]

Hi Marc, sorry not to have replied earlier and thanked you for this, but only just noticed your helpful post.

My son and I collected his car from the indy garage tonight. Just as you have suggested above, the carbon build up, probably coupled with leaking fluid had gunged everything up. Geno, the indy mech, sent the pump off to a specialist and had it reconditioned. After refitting and a bit of tweaking, the car now seems back to it's old self and performs well.

However, when we got the car back to my house, I decided to check the fluid level - I just wanted to satisfy myself that this was correct. I lowered the suspension, turned off the engine and slowly opened the reservoir cap, to find the LDS fluid overflowing! I quickly tightened the cap, got lots of towel to mop and soak up excess fluid and opened up the cap again. It looks to me as though Geno hadn't understood the instructions my son passed onto him from me (you guys) and had overfilled the system. I managed to carefully drain excess fluid from the tank until we got to about the right level, cleaned everything up, repressurised the system and the suspension seemed to operate properly.

My son has driven it 50 miles back to his home and is going to recheck the level tomorrow morning. I've also suggested following the method you'd posted in the past to bleed any air from the system. Thanks once again for your help and I'll post back with any more news, Paul.