Annoying hydraulic problem

samtronic · Post by **samtronic** » 25 Nov 2005, 18:31

Hi,

I seem to have some problems with the hydraulics in my '93 Xantia (non-activa, no anti-sink, single output pump, 215000km).

A bit of history:
I bought it a year ago. It worked fine, a bit slow to rise and sank a bit faster than it should, but otherwise fine.

Shortly after, I changed the LHM, which was a nice green, for Hydraflush and changed the accumulator and immediately it rose faster. It also stayed up all night now.

4000 km later it was getting slow to rise again and the sinking was faster. I replaced the Hydraflush with fresh LHM, cleaned the tank and replaced the filters. There was no crud in the tank. Again it rose fast and stayed up for hours.

Now a couple of thousand kms later it has begun to rise very slowly (20 sec. for lamp to go out and 1 min. to ride height) or not at all until I open and close the pressure release (half a turn).

When it hasn't yet risen, there is no servo steering. I guess that indicates that the flow divider works.

My best guess would be a problem with the pressure regulator, but is there something I can do about it short of replacing it?

Søren A.M.

Post by **Peter.N.** » 25 Nov 2005, 20:54

Could be the regulator but its more likely to be the pump not building the pressure up quickly enough, I have just had to replace the one on my XM. Have you tried cleaning the filters again?, or it could just be that the belt is slipping.

steviewonder7 · Post by **steviewonder7** » 25 Nov 2005, 22:03

Peter, Are these pumps not reconditionable then?

citronut · Post by **citronut** » 25 Nov 2005, 22:34

as peter said it sounds like a lazy pump,and yes you can buy recond units,what mileage sorry km has the car done,and how dose it translate into english miles
regards malcolm

samtronic · Post by **samtronic** » 25 Nov 2005, 22:50

Peter,

The aux belt feels tight enough, it was changed at the same time I put Hydraflush in and it has an automatic adjuster.

The filters in the LHM reservoir are clean. The old I removed was pretty clean too, even after Hydrafush, but I damaged the larger one and then changed both.

I just tried the following a couple of times:
Open pressure relief, hear hiss, see car go down, close pressure relief, start engine, wait for light to go out, wait for car to rise.

Every time: Light goes out after 5 secs.
1. time: Car goes up somewhat in 2 mins.
2. time: Car does not rise. Light comes back on after 40 secs and stays on for longer than I like (sometimes the light comes on for a second when the car begins to rise).
3. time: Car goes up nicely and is fully up in 35 secs. Engine dropped a bit in revs when car began to rise and pump sounded like working harder.

When I relieved the pressure I could hear hiss - click. I guess the click is from a valve/piston in the regulator.

Could it be that the regulator doesn't always close fully (due to wear or grit) when trying to build up pressure?

It might be the pump, it sounds a bit chattery (and have since I bought the car), but it can get the car up from flat in 35 secs when things behave.

Malcom, the car has done 215000km (134000miles). I don't know if the pump has been changed.

Søren A.M.

Post by **Peter.N.** » 25 Nov 2005, 23:25

I had to change mine at about 135k miles, it also was very clattery, in fact it has made the car considerably quieter at tickover. I have known them last a lot longer. If the car sorts itself out eventually that would seem to indicate that the rest of the hydraulic system is OK. Mine got a lot worse when the weather turned cold, although the suspension came up a little way and you could steer it, the light sometimes didn't go out for about 1/2 mile, and as I have to drive over a long rough track to reach the road, it wasn't doing the underneath any good! You usually find that one or more of the pistons become inoperative so its not pumping for the whole revolution.

You can obtain them in this country from GSF, reconditioned, for £115.00 + VAT but they charge you a hefty deposit to make sure they get the old one back, my total bill was £288.00! I have yet to return the old one.

Mandrake · Post by **Mandrake** » 25 Nov 2005, 23:41

Now a couple of thousand kms later it has begun to rise very slowly (20 sec. for lamp to go out and 1 min. to ride height) or not at all until I open and close the pressure release (half a turn).

What is the one thing that happens every time you change the oil ? Answer: you have to bleed air out of the regulator circuit.

It sounds to me like your pump is sucking in a little bit of air. After time more air will accumulate, and running the pump/engine with the bleed screw open helps to bleed air back out again.

If too much air is sucked in the pump will lose its prime and can only be primed again by running it with the bleed screw open.

Thoroughly check the hose from the resiovour across to the pump for cracks, especially at the ends, and replace it if you have any doubts about it. (You might be able to get away with cutting a little bit off the ends if the cracks are at the ends and you have enough spare length...)

Also replace the hose clamps at both ends with screw type jubilee clips if it still has the original crimp type clamps - the crimp ones get loose with age and can't be satisfactorily tightened. The one at the pump end on my car was so loose it allowed the hose to turn freely on the pump even though the clamp was clicked together properly....

Replacing a hose first, that might turn out not to be the problem, is much cheaper than replacing a pump that also might not be the problem!

As the saying goes, check the simple things first...

Also bear in mind that the pump itself can't have any effect on how long it takes the car to sink when parked - and naturally the more that it sinks and looses pressure, the more work the pump has to do to lift the car back up again, and therefore the longer it takes.

When it hasn't yet risen, there is no servo steering. I guess that indicates that the flow divider works.

No, the steering should have some assistance even while the car is lifting.

Regards,
Simon

samtronic · Post by **samtronic** » 26 Nov 2005, 00:04

Simon,

at closer inspection, the pump looks a bit moist at the connecting hose. I'll look into that tomorrow.

I'd rather not buy a new pump; it's sometning like GBP240+140 in deposit here. Even from GSF it is rather expensive.

Thanks,
Søren A.M.

AndersDK · Post by **AndersDK** » 26 Nov 2005, 05:02

Hej Søren -

Please note that Simon is talking the large rubber feed hose from the reservoir. I could hardly believe that it would be greasy as you can not see it leaking even if it is. Because the hose is under vacuum at all time.

It is however a common problem known from the earlier models (BX, GS, CX) that this hose perishes over time. Especially over the studs you can see fine hairline crackings - but also over the run of the hose it will have fine hairline crackings if you do the bend test.

The hose is special made for 2 reasons :
1) very thick rubber walls to prevent hose collapses (and blocks the pump feed)
2) as a consequence moulded in shape beacuse of the thick rubber

You can use any suitable diameter hosing that can not collapse (on bends) and will withstand mineral oils - as LHM is a mineral oil.
For testing and preliminary repair you can use suitable diameter garden PVC hosing - but I doubt it as a permanent solution because it can not keep its shape and may collapse.
This advice because you may get a heart attack when you try source a new hose and is informed the price tag

Edit : Errrr... the Xantia pump is located low down - meaning the feed hose could in fact leak by the weight of the LHM inside the hose

(earlier models have the pump higher than the reservoir)

Mandrake · Post by **Mandrake** » 26 Nov 2005, 06:59

AndersDK wrote:Edit : Errrr... the Xantia pump is located low down - meaning the feed hose could in fact leak by the weight of the LHM inside the hose
(earlier models have the pump higher than the reservoir)

You're half right Anders

It depends on the engine...

The 1.9TD has the pump down low below the alternator, however the 2.0 8 valve petrol has the pump right at the top above the alternator, almost level with the tank, but probably fractionally lower. See this pic:

http://homepages.igrin.co.nz/simon/imag ... ngine1.jpg

I don't know what the situation is with other engines like the 1.8 petrol though...

Regards,
Simon

AndersDK · Post by **AndersDK** » 26 Nov 2005, 17:03

Tx Simon -

Must then further Edit : depending on engine type/model/year the pump may be located above or below reservoir level ...

john alexander · Post by **john alexander** » 26 Nov 2005, 18:17

Hi. I am also slow to rise , quick to drop and can't stay up for long . how much hydraflush should I drink .?. regards john.

steviewonder7 · Post by **steviewonder7** » 26 Nov 2005, 18:23

Dont mean to hijack this thread,but would it be feasible to use a length of copper pipe bent to the correct shape with the correct type of hosing clamped
at either end.I,m thinking of 15mm copper tubing as used for central heating or is this too thin?Just an Idea,might save a few pennies!!

samtronic · Post by **samtronic** » 27 Nov 2005, 00:14

Thanks all,

The hose was very loose at the pump; I could move it without much effort.

I tried fixing it with a jubilee clip, but the cheap piece of c**p fell apart

Instead I had to tighten the original clip and it is now pretty tight and the whole thing is working fine, but it took some time to get it to prime.

The pump is located above the alternator like Simon's and is a bit lower than the reservoir and the hose goes over the pump, thus a bit of fluid would be able to leak out when there is a leak and the engine is stopped.

The car now rises pretty fast, ticks every 50 seconds and passes the sit-in-boot-with-engine-off test.

Thanks,
Søren A.M.

PS: Try coffee, John

Mandrake · Post by **Mandrake** » 27 Nov 2005, 00:41

samtronic wrote:Thanks all,

The hose was very loose at the pump; I could move it without much effort.

I tried fixing it with a jubilee clip, but the cheap piece of c**p fell apart Instead I had to tighten the original clip and it is now pretty tight and the whole thing is working fine, but it took some time to get it to prime.

The pump is located above the alternator like Simon's and is a bit lower than the reservoir and the hose goes over the pump, thus a bit of fluid would be able to leak out when there is a leak and the engine is stopped.

The car now rises pretty fast, ticks every 50 seconds and passes the sit-in-boot-with-engine-off test.

Glad to hear it

I presume you took the hose off in the process of trying the other clamp? If so you probably let some air in the pipe, thus the difficulty getting it to prime at first.

Usually you would pour some oil into the hose so that as much of the hose as possible is full of oil before reconnecting it, then make sure the bleed screw is open when first starting the engine - this takes the load off the pump, and also allows any trapped air to be recirculated right back to the tank where it bubbles out into the air rather than letting it find its way into the main hydraulic lines where it will cause trouble.

Then just run the engine for a few minutes with the bleed screw open, and you'll probably notice a bit of bubbling or frothing in the LHM resiouvour - this is the air bubbling out. After a few minutes it should stop doing that, at which time you can close the bleed screw to let it fully pressurize and then your job is done.

As for the clip, Jubilee clip may not be the right kind - over here we don't call them that, we just call them "hose clamps", and they are made of stainless steel, have a steel strap with slots in it, and a worm drive screw with both a hex and slot drive, and they are VERY strong and reliable, no way could you break one by overtightening it on a rubber hose, you'd crush the hose first.

Personally I'd consider reclamping the original crimp clamp to be a temporary repair, or at least remember to keep an eye on it to make sure it doesnt work loose again...

Regards,
Simon

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Annoying hydraulic problem

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