French Car Forum

KEB1 · Unread post by **KEB1** » 29 Apr 2006, 15:04

Hi All,

I am wondering if I could "pick the brains" of the many knowledgable enthusiasts who make up this forum ?
Although the car has long since gone (and I wish it hadn't) our old 1975 CX had a peculiar suspension problem which I am not sure ever got cured.
With only the driver and a front seat passenger, the suspension did all that it was designed to do.
However, the problem was that with a full complement of passengers, after about a 1/2 - 1 hours drive if you stopped the car for any reason, when you returned, the rear had sunk down and would not rise again for at least an hour.
When it was drivable again, the height regulator would be heard "clacking" away. Also, if you tried to drive it away without it gaining the correct height, braking pressure was lost.
The accumulator sphere was changed, the single piston pump was overhauled and much attention was given to the rear height correctors but all to no avail. Two Citroen dealers said that they could cure the problem and were allowed to look at it. On the last occassion the dealer declared the problem was solved. However, the subsequent owner came back a couple of weeks after it was sold demanding we pay for a later type of belt driven pump he had had fitted by a specialist as he had had the same problem.
We offered to buy the car back from him but he refused. However, about three months later it was for sale on a local Renault dealer's forecourt .
Although as I said we no longer have the car, this is something that has bugged us ever since.
It defeated two Citroen dealers and I think an independent Citroen specialist
Can anyone out there help us to close the book on this one

All the best,

Kristian,

Unread post by **Peter.N.** » 29 Apr 2006, 15:28

Having owned four CX DTR Safari's I thought I had come across most faults, but not this one I am afraid. My earliest was a 1980 which by then had the multi piston pump. It sounds like loss of hydraulic pressure to the rear, when you said it affected the brakes, was that all of them or just the rear? If it was the rear only it could have been something to do with the brake valve, but if the front as well, a general loss of pressure, which without the car would be a bit difficult to find!

citronut · Unread post by **citronut** » 29 Apr 2006, 17:11

as peter said it sounds a bit like the BX sindrom of clapped out brake dozer valve,apart from the BXs usualy rise almost straight away,so may be the BX sindrom and a sticking rear hight corector
regards malcolm

KEB1 · Unread post by **KEB1** » 29 Apr 2006, 17:40

Bearing in mind that all this occured some years ago the memory is that most of the braking pressure was lost and the car had to be nursed back to the dealer on the hand brake with the suspension almost bottomed out.
I feel I should also point out that when the car was sold, because we had a new 2CV, we had been fully assured by a Citroen main dealer that the problem had been fully cured by fitting a new rear height corrector.
The new owner was told about the problem before he parted with the money, which was next to nothing anyway.

Kristian.

Unread post by **alan s** » 30 Apr 2006, 00:35

After 22 years of owning CXs on & off, I thought I'd heard them all too but this is a new one.

I would suspect a dirty system possibly more so in the rear of the car in the region of the brake dead ends. Being a 75 model, it shouldn't have had diravi steering IIRC unless you guys saw them before we did, so it would have had the old style pump bolted to the block that operated off the camshaft. They didn't have a great capacity but they worked well and I doubt changing that did much apart from lighten your buyers wallet. It almost had to be a blockage that over time allowed fluid to seep back to where it should be.
I recently posted about the insides of height correctors I was shown at a friends place and inside them, there's a series of 8 small stainless steel discs with a small pinhole through the centre and held apart by spacers which under normal circumstances are never removed when people strip height correctors and clean them and I suspect that the crappy fluid possibly got in there and simply kept blocking off these holes which could also explain why the dealer was so sure he'd fixed it. It would start off OK but as soon as the much got in there and progressively filled this region up in the H/C the problem would reappear.
I would say the only possible cure would be to fit a known good H/C, drain and refill the LHM tank with either fresh LHM or Hydraflush and bleed the rear brakes until cklean fluid came out. Replace the H/C with a reconditioned (cleaned properly) one and see what happens.
My guess is that was the problem.

Alan S

DoubleChevron · Unread post by **DoubleChevron** » 30 Apr 2006, 07:41

Yeah,

it could have been an internally sludged up height corrector. The braking issues and 'clacking' pump however scream to me "pumps sucking air".

No doubt you could have spend thousands and thousands on that car replacing the pump, height correctors etc......... Only to find a small crack or dodgy hose clamp on the pumps feed line was allowing the pump to suck air, and in doing so take a large amount of time to self prime.

seeya,
Shane L.

Unread post by **Peter.N.** » 30 Apr 2006, 08:38

It would seem from what Kristian says that there was a general loss of hydraulic pressure, because if it was only the back brakes that were not working, I doubt if you would notice much difference. On a 'conventional' car two thirds of the braking effort is applied to the front wheels, with a lightly loaded rear, on a hydrapnumatic system its probably a lot less, the brake pads seem to last forever! But we shall probably never know now.

DoubleChevron · Unread post by **DoubleChevron** » 30 Apr 2006, 10:51

Peter.N. wrote:It would seem from what Kristian says that there was a general loss of hydraulic pressure, because if it was only the back brakes that were not working, I doubt if you would notice much difference. On a 'conventional' car two thirds of the braking effort is applied to the front wheels, with a lightly loaded rear, on a hydrapnumatic system its probably a lot less, the brake pads seem to last forever! But we shall probably never know now.

The rear sinks quickly, from the description is totally unrelated to the rear of the car, the reason the rear isn't lifting is there is no pressure available to lift it ... The reason the brakes have almost gone is the accumlators are almost flat from sitting, and there is no hydraulic pressure recharging them ... The reason pumps rattle and don't create any pressure is they have no fluid in them.

Seriously this is a really simple problem that scream really loudly "FIX THE MAIN RUBBER LINE TO THE PUMP "

Eventually given time the pump will self bleed and all will be perfect until next time it looses it's prime

I'm quite surprised Citroen Specialist woudn't immediatly identify the problem given your very accurate description (that includes pump rattling).

seeya,
Shane L.

Unread post by **Peter.N.** » 30 Apr 2006, 15:50

Was that a problem on the CX ?

DoubleChevron · Unread post by **DoubleChevron** » 01 May 2006, 00:30

Yeah I think he said it was a CX .... However his problem could have been on any car.... DS, GS, BX, CX etc..... Though on a later CX the lack of power steering would have screamed "No Hydraulic Pressure" to everyone that looked at it

seeya,
Shane L.

KEB1 · Unread post by **KEB1** » 01 May 2006, 15:31

Thanks to all who responded to my question. What a pity sites like this did not exist when we had the car.
I am sure with all the knowledge that is within the group, to coin a phrase "the cass would have been sol-ved"

All the best,

Kristian.