Simon's new Xantia V6 and Leaf blog

[white exec]

I'm also unable to access s.c - "invalid user" on log-in.
Hopefully a glitch.

[Mandrake]

I'm also unable to access s.c - "invalid user" on log-in.
Hopefully a glitch.

Service Citroen was working for me shortly before I posted, however when I tried now I got:

"The Time To Reset Password Has Expired.Try again!
Already registered"

I then closed the browser, logged back in again and seem to be back in, but the UI style of the website seems to have changed a bit. So I think they might have just done some maintenance/upgrade work to the site!

So maybe worth clearing anything related to the site (cookies etc) and going back to the login URL.

[RichardW]

Still can't get onto the on line version...

My off line version gives this however, it will be item 3:

V6 appears to be the shortest one, so one from another car would do, but it will be *much* easier to fit a Kunifer one. Just order up a 1.9m length and away you go. I still reckon getting the end on the security valve is going to be a mare....might be worth asking David as he repiped an HDi, and I recall he had trouble in this area. Potentially if the rest of the pipe is good, and you can get a joiner you could flare the pipe under the car and graft a new piece on.

[RichardW]

Here you go....

Eurocarcare do a compression joint for repair which doesn't need a flare: Repair joint

And pipe by the cm: Pipe

Cut the old one off under the engine somewhere, measure the bit off the accumulator, get a pipe to suit, shouldn't be too hard.

[Mandrake]

Still can't get onto the on line version...

My off line version gives this however, it will be item 3:

I did come across that diagram in my original searching but there is nothing in it to confirm that the coiled up pipe is one of those ?

I was under the impression that it went to the flexible hose which then goes to the hydraulic pump, but maybe I'm wrong.

I'll have to remove the air filter assembly (Ha! Step one in every V6 job ) and possibly the battery tray to get a better look to be sure, I think access is quite good once the battery tray and air intake bracket attached to it are removed, and the car is not going anywhere until fixed anyway!

V6 appears to be the shortest one, so one from another car would do, but it will be *much* easier to fit a Kunifer one. Just order up a 1.9m length and away you go. I still reckon getting the end on the security valve is going to be a mare....might be worth asking David as he repiped an HDi, and I recall he had trouble in this area. Potentially if the rest of the pipe is good, and you can get a joiner you could flare the pipe under the car and graft a new piece on.

Assuming the pipe does go to the security valve instead of the pump...I don't know where the security valve is on the V6, I'm guessing down the back of the engine... Back of the engine access is actually better in the V6 than the HDi's you're used to though (you can get a whole arm down the back of the engine without removing anything... ) so it might not be as hopeless as it first seems.

However unless I had a complete replacement pipe there would be no point in going all the way to the security valve since it would need joining downstream instead. Two compression joints and a new coiled section wound from cunifier will be a bit clunky looking but I suppose if it does the job to keep an old car on the road...

If it's not raining tomorrow I'll try to strip it down a bit for a better inspection.

[white exec]

Don't use olive-compression joints for repair work on Citroen steel hydraulic lines, despite some advertisements for these.

The pressure of 170bar+ is beyond the capability of this type of joint, and the olives do not make sufficient indentation into the steel pipe (as oposed to copper or cupro-nickel) to hold firm. This type of joint was specifically prohibited (by UK MoT testing regs) from use in repairing brake lines.

The 'olives' used in Citroen HP pipes are formed from a swage of the steel pipe itself (plus a sleeve rubber).

I'm sure the pipe details can be identified when we get access to Parts again, and an outfit can be found to make one up, if NFP.

That type of joint would only be appropriate as a temporary measure, eg to allow the car to be put on a ramp for repair.

[Mandrake]

When I look up pipe 3 specifically for my VIN it gives a match for 5270 GC - so assuming this is the pipe in question it is definitely one of the two that is NFP. So repair, after market or 2nd hand replacement looks to be the only option.

[Mandrake]

I'm sure the pipe details can be identified when we get access to Parts again, and an outfit can be found to make one up, if NFP.

I'm having no difficulty logging in, not sure why other people are ?

[white exec]

There was a similar coiled pipe on the BX, the coil allowing for engine movement relative to the body, where the security valve is mounted.

[RichardW]

You're probably right, Chris - I had in the back of my mind there was something about compression fittings in brake lines. At work they use Swagelok twin ferrule fittings which are good for lots of pressure, they don't do a 4.5mm of course....

AFAIK the security valve is bolted down on to the rear of the subframe somewhere!!

[Mandrake]

Don't use olive-compression joints for repair work on Citroen steel hydraulic lines, despite some advertisements for these.

The pressure of 170bar+ is beyond the capability of this type of joint, and the olives do not make sufficient indentation into the steel pipe (as oposed to copper or cupro-nickel) to hold firm. This type of joint was specifically prohibited (by UK MoT testing regs) from use in repairing brake lines.

I wasn't aware that olives had to actually bite into the pipe they are sealing to be effective ? Surely the point of an olive is that it is soft enough to deform between the taper in the nut and the pipe to take the exact shape of the gap between the two thus form a seal. While the pipe of an olive joint does typically deform slightly I'm not sure that's necessary. Likewise a rubber o-ring seal works by deforming to the micro contours of what it is sealing and seals without deforming the host materials at all.

After all olive joints are used not only on copper plumbing pipes (which do deform under the force of the olive) but also on radiator end fittings which are chrome plated steel, which do not deform, and seem to seal just as well as on copper. To be fair, at much, much lower pressures than we're talking about here.

The olives used in Citroen HP pipes are formed from a swage of the steel pipe itself (plus a sleeve rubber).

3.5mm and 4.5mm Citroen pipes don't use olives at all. The primary seal is a close tolerance fit between the outside diameter of the tip of the pipe and the inside diameter of the bottom of the hole, it's a tight enough fit that the pipe ends often get stuck in the hole. The secondary seal is the rubber sleeve, and the swage in the pipe is only there to give the nut something to bottom on.

I'll take your warning under advisement but I'm not 100% convinced that you are correct about the danger.

To be honest I'd be more concerned about trying to get an olive to seal on the scabby surface of an old pitted/corroded pipe. Like plumbing fittings the pipe would need to be clean and smooth to get any sort of seal, that could be a challenge on the old pipe.

[white exec]

Simon, it is the case that 'dry' olives do have to bite into the pipe involved to create a seal where any significant pressure is involved.
If they don't, all the joint has is friction to hold it together, and that is not good enough for our 170bar+ hydraulic systems. For plumbing work, where pressure is much lower (3-10 bar often), a brass (or steel) olive biting into a copper pipe is ok.

Citroen hydraulic joints with their integral bulge in the pipe rely on the bulge (with the locking tube-nut behind it) compressing the rubber sleeve into the inner space. These are clever joints, inasmuch as hydraulic pressure actually increases the strength of the seal by compressing the rubber. The pipe end, where it enters the inner drilling, does not form a seal on its own. The running order is: pipe end, rubber sleeve, bulge, tube-nut . . . in that order. I can post a Citroen drawing, if needed.

Finally got into s.c.....
Don't have your VIN handy to absolutely check
5270GC looks like it, and you can see the coil on this diagram:

The pipe length is listed there.
If you can identify the pipe ends, one of the companies who make up new Citroen pipework should be able to run up a pipe for you. You can wind your own coil in the appropriate position.

[Stickyfinger]

err....I might have one of those hanging up in my workshop..............will check in the morning if you want

[Mandrake]

Citroen hydraulic joints with their integral bulge in the pipe rely on the bulge (with the locking tube-nut behind it) compressing the rubber sleeve into the inner space. These are clever joints, inasmuch as hydraulic pressure actually increases the strength of the seal by compressing the rubber. The pipe end, where it enters the inner drilling, does not form a seal on its own. The running order is pipe end, rubber sleeve, bulge, tube-nut . . . in that order. I can post a Citroen drawing, of needed.

I'm quite familiar with how the Citroen unions work, and have studied the drawings before and I don't think your description or understanding is correct.

If you've ever forgotten to fit the rubber seal on one of these unions you will have found that they only dribble a small amount - there is no flood of oil as there would be if the rubber sleeve was the primary seal. This makes it obvious that the metal to metal seal on the tip of the pipe is the primary point of sealing and that the rubber seal is only holding back leakage pressure to complete the sealing.

The bulge in the pipe does not compress the rubber sleeve against the side wall - if it did, it would be impossible to insert the pipe into the main hole with the rubber pushed over the bulge - when in fact it slides in easily with no resistance as the rubber is a loose fit in the hole even when stretched over the bulge in the pipe.

The bulge in the pipe is definitely there for the end of the nut to push against to press the tip of the pipe tightly into the small diameter hole to ensure it seals, and when you nip up the nut the last bit you are clamping that pipe end firmly into the small hole. And in doing so it compresses the rubber sleeve between the face of the nut and the bottom of the large diameter portion of the hole. Since the rubber sleeve is longer than this gap by a precise amount the rubber sleeve bulges out to seal on the outer wall due to this compression, not due to the bulge in the pipe.

It is a clever design but it certainly doesn't rely on the rubber alone to seal the high pressure.

[Mandrake]

err....I might have one of those hanging up in my workshop..............will check in the morning if you want

Oooh err, yes please....!