Major LHM leak

[Rob_e (UK)]

On the way into work the other morning the hydaulic warning light came on, so I pulled over had looked under the car to see LHM spraying out of the back end of the car at quite a rate.
The car has now been recovered back to my house but I haven't managed to look under it yet; not quite sure yet how I am going to get any access to it.
Any thoughts on most likely cause? my current thinking is that it is probably the main supply pipe to the rear height corrector as I wasn't putting the brakes on so it propably isn't a brake pipe, the suspension was just at normal height driving along so propbably not the return, and the suspension had not collapsed at the rear and I would have thought it would had it been a pipe to either cylinder or the supply to the brake valve from rear suspension.

The rear height corrector is only a year old and seemed to be working normally prior to the car deciding start on its own LHM change by pumping most of the resevoir onto the road, so hopefully that won't have sprung a leak.

I was going to take a chance and just order this pipe the other day in an effort to try and get the car back on the road as quickly as possible, but when I phoned Pleiades to try and get the pipe made up the guy said he was out of the 3.5mm pipe, so I am not sure where else I might be able to get one made up?

Thanks in advance
Rob

[citronut]

is the leak N/S rear just forward or behind that side wheel, as quite often the front to rear pipes chaf through around the top they disapear over the rear sub frame/rear susp arm, especialy if they have been either disturbed or badly fitted on a pipe change,

i always lower the rear sub frame when fitting a set of pipes,

were abouts are you Rob, as i have quite a selection ofBX and other hydraulic pipes, as i bout some as a job lot a couple of years ago

[DLM]

Sorry to hear about this - not a nice problem to deal with.

not quite sure yet how I am going to get any access to it

This is one of the times when a sturdy scissors jack could prove useful, as could bottle jacks, for use under the rear subframe and its mounts to raise to stand height.

IF it were an estate with towbar I'd risk a very careful initial raising under the towbar, but I'd be a lot less sure of this on a hatch on corrosion grounds. You probably haven't got a towbar anyway...

[Rob_e (UK)]

is the leak N/S rear just forward or behind that side wheel

No I think it was pretty much in the centre of the car over the rear subframe, possibly slightly to the left, as it seemed to be spraying fluid over the exhaust; although managed to cover quite alot of the under side I think.

i always lower the rear sub frame when fitting a set of pipes

That makes it sound like a very big job I was sort of thinking that once I had access under the car the most difficult bit would be getting the pipe connected to the Security valve; I have never had to do any thing with that, but it always looks quite well tucked in out of reach?

were abouts are you Rob

I am in Hertfordshire.

This is one of the times when a sturdy scissors jack could prove useful, as could bottle jacks, for use under the rear subframe and its mounts to raise to stand height.

I don't have a scissor or bottle jack. I usually use the wheel changing jack when the suspension is working. I have got a couple of trolly jacks but I don't think they will go under it at the moment.

As far as lifting equipment I am rather pinning my hopes on an inflatable air jack that I bought a while ago, as it looked like it could be quite useful for this sort of situation where the car was really low, This is what I mean for anyone that hasn't seen one
http://www.alltoolsdirect.co.uk/draper- ... 2284-p.asp

I am assuming I need both ends of the car off the ground for this repair so my dilema is how to go about this without risking it toppling off anything in the process of lifting it.

I was thinking I may be able drive the front end up some drive up ramps to get that end up, I think the bumper may just clear them else driving on to a couple of bits of wood first may give the clearance.

I would then need to lift the back end up, but where can I lift it from? The rear subframe is going to be quite slippery at the moment with all that LHM, and also I am concerned with so little visibility under the car about damaging any other pipework or height corrector linkages.
Given this sort of jack would spread the load quite a lot, could I get away with putting it under the spare wheel? or is the boot floor not going to be strong enough for that.

I could do one side at a time perhaps, then I could lift under the sills. But when the car is so low, whether I use axle stands or drive up ramps under the wheels, I would think that there is quite a risk of it pushing them over side ways.
Any thoughts?

Unfortuantely when the recovery guy came out he had just a flatbed truck where the whole bed moves to become a ramp; he said they often use the trucks with the hydraulic arms to just lift them on when they come to collect citroens. If only he had brought that this time I might have been able to get hime to lower it straight on to the drive up ramps instead of the road and saved me this problem.

Thanks in advance
Rob

[DLM]

No I think it was pretty much in the centre of the car over the rear subframe, possibly slightly to the left, as it seemed to be spraying fluid over the exhaust; although managed to cover quite a lot of the under side I think.

You could well be right on the height corrector front, given lack of immediate sink and position. Exhaust side should be the H/C feed side.

As far as lifting equipment I am rather pinning my hopes on an inflatable air jack ....I am assuming I need both ends of the car off the ground for this repair so my dilema is how to go about this without risking it toppling off anything in the process of lifting it.

Hmmm.... never used one. I used a trolley-jack on a towbar when doing a similar thing - carefully, and only very quickly until I could support under the rear subframe. I didn't need to raise the front and had no front bumper-fouling issues on a standard bumper.

I'm not sure the air jack's the ideal tool but the only one you have at the moment - unless you can borrow more suitable and more controllable tools. I do feel you need to get the rear of the car up on stands before you'll know 100% what's to be done. Once the rear's up, you should still be able to raise the front if needed by hook or crook.

I did find a couple of reviews of this jack - including descriptions of pitfalls, which I'm sure you've researched - in particular the state of the exhaust system and whether it fits a BX exhaust tailpipe. I'd be inclined to try the jack out next to the car first to find out how effective and controllable it is, and also remove the HP pump belt if you do use it to avoid further mess.

Using the spare wheel to spread the load isn't ideal, but the towbar-lift method also relied on the floorpan being strong enough, but spreading the load through the underfloor box sections, which I believe aren't quite as subject to corrosion as hatchback ones. I guess where the bag could go depends very much on the size of the bag. How big is it?

[Rob_e (UK)]

I haven't actually ever used it so don't know for sure how well it works, or if it fits the exhaust; although I was actually considering connecting it to the exhaust on another car, mine does leak a little.

If I did need to start it to put it on ramps or whatever I was thinking that losening the pressure release screw should hopefully stop any more fluid being pumped out as the security valve should close off that circuit if the pressure stays low.

You're right I should just get the back end up first, to be sure where the leak is coming from, especially if finding a replacement pipe is going to prove difficult.
I was just thinking about getting the front end up first on the assumption that if I needed both ends off the ground, then getting the front up on ramps first would leave the lighter end to try and jack up, also the front wheels have the brakes on them so it would keep it a bit steadier.

Thinking about it the back end is the worst area of the car for rust so perhaps I would be pushing my luck expecting the boot floor to take too much strain.

The bag when inflated is supposed to be 480mm in diameter and 545mm in height.

Thanks,
Rob

[Jaba]

That bag looks useful but it would get in the way of getting under the car to find your leak if it was used anywhere at the rear end.
Why not put it under the sill at the jacking point and raise the car on the leaking side. Support and chock the car then you will then be able to get under and see where the leak is.

Having done that you can then lower it on to a trolley jack or axle stand and raise and support the other side if you need more access underneath to get in to replace the failed component.

A few further thoughts. You may need to raise both sides to be able to remove the rear wheel. This is always a fiddle on less than full height.
There is not much that could have failed and leaks when under pressure at the rear, just four pipes, height corrector & struts, so it should be easy to find.

[Rob_e (UK)]

I was only planning to use the bag to lift it, then take it out the way when I wanted to get under it. I was considering lifting one side at a time, but I was a little concerned that it might put quite a sideways force on the stands or ramps and so could fall off, especially if I then started trying to lift the other side. But I have't ruled anything out yet.

The leak was pretty much in the centre of the car, unfortunately so I do need to be able to get right underneath it.

Last night I managed to get the back end up on the drive up ramps. It didn't go very well. I tryed driving it onto a couple of bits of wood first to get the rear bumber high enough to clear the ramps; unfortunately I was looking at the drivers side when I decided it would clear it, and when I started to try and get it on the ramps the tailpipe caught on the ramp and snapped most of teh way off; so now I have a blowing exhaust as well. I think that was the only bit that was damaged so I can hopefully just weld that back on once I have the suspension fixed.

I then cut an angle on the end of some bits of old fence post to use as a smaller ramp, in front of the drive up ramps and this was high enough to clear everything; so I now have the back end of the car on ramps. By the time I did all this I ran out of time so didn't get a chance to find the leak, weather permitting I will have a look under it tonight.

I replaced one of the rear cylinders quite recently so hopefully it won't be that, and I think it was two far forward, over the rear subframe. And the supply pipe to that one was replaced at the same time as I had to cut the old one off at the union to get the old cylinder out.

Thanks,
Rob

[Rob_e (UK)]

Well, I had a look under the car last night to try and confirm where the leak was coming from. As there was so much fluid all over the place I had to clean it up a bit and then repressurise the system to get it to leak again.
I couldn't get under the car while it was leaking as it sprayed out so fast there was a sort of fin mist of LHM coming out. But once the flow had stopped I could see it was a bit further to the left of the car than I originally thought. The area above teh height corrector and the corrector it self were dry and the floor pan above where the four pipes go accross the car was covered along with the top and back of the centre box.

So it is one of the pipes, although I couldn't see any holes, but judging by the way the fluid came out I guess it could just be a small pin hole, there are a couple that a quite corroded. As the manual ehight leve in the car was on low I assume it must be the supply to the HC.

I ordered the pipe from Citroen this morning, I would have prefered no get one from Pleiades rather than the steel ones Citroen supply but I can't wait two weeks for them to get more pipe in.

I noticed all the pipes are clipped together at various points by a plastic clip thing that seems to go all the way round the pipe. How do you get pipes out of those? does the plastic bit open up some how?

I don't want to break any of the other pipes trying to get that one out.

Also any ideas on teh best angle to try and get to the connection on the security valve?

Thanks in advance
Rob

[citronut]

the pipes at the security valve are easy, but if you have trouble just undo the 10mm nut and bolt fixing it to the sub frame and ease it out enough to get at the pipe nuts, the plastic pipe mounts just pull the outer face off evenly and very gently as the plastic peg snaps off readaly,

on re/fitting the pipe/s make absolutly sure it/they are not touching each other or any part of the car body or susspension trailling arm, as any of these will cause premature pipe faliure,

this is why when i fit a set of rear pipes i always lower the rear sub frame, not as hard as it might look,

also there is nout wrong with the new genuine steel pipes, as they are powder coated and last a very long time, unless disturbed or chaffing on something elss,

earlyer citroen hydraulic pipes were galvanise coated which over time the coatting used to break down, leaving them open to rust

regards malcolm

[DLM]

I noticed all the pipes are clipped together at various points by a plastic clip thing that seems to go all the way round the pipe. How do you get pipes out of those? does the plastic bit open up some how?

Does this pic help at all?

[DavidRutherford]

So it is one of the pipes, although I couldn't see any holes, but judging by the way the fluid came out I guess it could just be a small pin hole,

Not that it's really of any relevance, but what tends to happen is that the pipes split along their length. When you remove the old pipe you may well find that there's a split of some length along the pipe, rather than it being a single round hole. This is why when they fail, they fail so catastrophically. A small pinhole would be sustainable for a little while at least, but a 10mm long split in a line means instant pressure loss.

[Rob_e (UK)]

also there is nout wrong with the new genuine steel pipes

I guess the original has lasted 20 years, so the coated ones should outlast the rest ofthe car.

Does this pic help at all?

I think from the angle I was looking at them, where the pipes go accross the car, I must have been looking at the underside of one of those clips, so all I could see was the flat bit so I couldn't see how they come out; Now I can see they must come out the other side.

One other thing, is there any way of telling which connection on the height corrector is the HP supply? Or do I just need to follow the pipe from the security valve all the way to the back? One pipe can be identified easily as I can see it conencting to the cylinders but as the HP supply and the return both disappear over the sub frame it is not that obvious which is which when under the back end.

Thanks
Rob

[citronut]

I must have been looking at the underside of one of those clips, so all I could see was the flat bit so I couldn't see how they come out; Now I can see they must come out the other side. ,

probably not as the later BX's did/do have a diferant sort of clip, which has two parts, one part is fitted to the body/chassis rail which the pipes lay into, then the other part has two pegs which locate into holes in the firts part and over the pipes, to remove this type very gently prize the outer part away so not to snap its pegs off,

i did draw the pipe layout a good few years ago but have not fitted a hole set of pipes for quite some time now,

but if they are as they were originaly fitted they lay in the same order the length of the car

regards malcolm

[citronut]

I must have been looking at the underside of one of those clips, so all I could see was the flat bit so I couldn't see how they come out; Now I can see they must come out the other side. ,

probably not as the later BX's did/do have a diferant sort of clip, which has two parts, one part is fitted to the body/chassis rail which the pipes lay into, then the other part has two pegs which locate into holes in the firts part and over the pipes, to remove this type very gently prize the outer part away so not to snap its pegs off,

i did draw the pipe layout a good few years ago but have not fitted a hole set of pipes for quite some time now,

but if they are as they were originaly fitted they lay in the same order the length of the car

regards malcolm

ps.
out of all the many sets of pipes i have replaced over the years, i have seen more pipes needing replaceing as a direct result of damage through shaffing than i have pipes just splitting open at the seems