Can you Bend 3.5mm Hydraulic pipe?

[xantom]

Hi Everyone, My Green Xantia Estate 1.9TD, N Reg, has just sprung a leak from the pipe that exits the rear height corrector, crosses over the rear accumulator and goes into a K junction on the side of the accumulator mounting. Not a big run and the junctions look easy to get to although they are very rusty and will probably resist being undone. I've been looking around and can get lengths of 3.5mm pipe with the junction nuts attached to properly flared ends. However, I'm not massively confident of bending these into the correct form. Are they rellatively easy to bend, successfully? If they are, and I assume they must be given that people sell unformed lengths, any tips or pointers on getting the job done? If it seems easy enough I'll probably do all the short lengths around the height corrector at the same time. Typically, the car has only recently passed it's MOT.

[white exec]

No problem in bending 3.5mm pipe, so long as you curve it gently around a former (eg another curved surface), or use a hand-held pipe bender. Just avoid sharp bends, which could cause the pipe to collapse.

Use new Citroen rubber joint seals on the unions, and ensure that the tip of the steel pipe squarely enters the K- etc fitting, so it enters the 3.5mm central drilling. Lube with LHM when fitting, and tighten, but don't overdo it.

Does look in need of some wax protection under there!

[mickthemaverick]

Yes they can be with the right tool, there is an example here:

https://www.ebay.co.uk/itm/274331158696 ... SwI49ejgHk

You will find it helps to gently warm the tube with a suitable hot air gun first.

[aerodynamica]

Hi Tom, the pipes are easy to bend - especially if they're supplied in the copper-nickel material. You really just need a rounded former like a 20-30mm dia pipe or something to make the bends.

The old pipe end unions can be trouble due to them rusting and being small size 8mm nut ends but if the pipe being removed is scrap anyway you can just cut the rusty pipe off at the union nut and get an 8mm socket on it or a set of grips. Maybe wire brush it first and spray some penetrating oil on it first.

You will also have to raise and support the back of the car first and depressurise the hydraulics before touching the pipe. On Xantias made after about 1994 the system changed to the anti sinking suspension and the pressure in the suspension circuits gets locked out when the main system pressure drops below a certain value so in order to reliably depressurise the rear suspension if you're lowering the back onto axle stands from say, the rear wheels up on ramps, make sure the engine is running when the low suspension setting is selected and leave the engine running until the rear circuit is fully depressurised (can tell by the rear struts getting loose in their seats - grab a rear sphere and give it a sideways tug).

The pipe union seals should be replaced with new although often I've reused them . And when fitting a new pipe I always slide the union up away from the flare initially so that the new pipe straight just before the flare can be seen to go in the center bore of the threaded bore because it's not uncommon to end up tightening the union nut when the pipe isn't fully in and this damages the pipe end and can also wreck the threads if tightened too much when the union nut isn't in deep enough. It's not hard to get it right in first time though.
Also have a spare bottle of LHM handy to top up afterwards.

So quire doable if you take care. And of course, never get under a hydraulic citroen unless it's solidly supported on stands!

[aerodynamica]

Yes they can be with the right tool, there is an example here:

https://www.ebay.co.uk/itm/274331158696 ... SwI49ejgHk

You will find it helps to gently warm the tube with a suitable hot air gun first.

Even better !

[xantom]

Thank you guys. I've bought and received the pipe bender and spoken with the guys a Eurocarcare about pipework. Very helpful, and I've ordered a length of pipe with unions and seals fitted. I'll get the split pipe replaced as soon as it and the LHM arrive. Bought another 5ltrs of LHM from Smith and Allan. I've been through quite a bit with this and the previous leak on the blue Xantia. As Chris said, it looks in need of Waxoyl under the car. More than that though; the other pipes aren't looking too good either so, given that I've got a flaring tool already, a new pipe bender and a supplier of pipe and attachment bits, I'm going to make a project of replacing every bit of dubious pipe I can find under the back end and if that's successful, move to the front. I've not been able to find non-compression 3.5mm pipe connectors but Eurocarcare have convinced me that compression connectors are no less reliable so I'm up for the challenge. Thanks again for the advice, I'll let you know how it goes. Tom

[white exec]

Whatever they say, do not use olive-compression unions on this pipework.
It is prohibited by UK MoT regulations for braking circuits.

Olives work by digging into the pipe they're fitted to. There is no way that a compressible (usually brass, sometimes thin steel) olive will dig into our steel pipes. They will just clamp there, until the vibration and pressure eventually loosens them. Citroen never used them, and for good reason.

For cupro-nickel replacement pipe, which I guess is softer, they could work - but are still an immediate MoT failure if spotted.

Just replace the entire pipe, or, use your swaging tool to create two proper Citroen joints, and use a Citroen straight-through threaded joiner.

[xantom]

Well, learn something new every day. Thanks for that, Chris. Plan B it is. Does anyone know any companies that supply the straight-through connectors? My wife has twice now 'suggested' I just replace the whole pipe but that seems a much more physically complex task to me and I'm pretty sure that much of the pipe run is in good condition, although I havent actually checked forward of the rear suspension because of the access awkwardness. Back into the internet searching for me tonight. Tomorrow the pipe arrives so I'll get that on and hope the LHM isn't far behind. That way she'll be operational again even if I will feel nervous about pipes splitting anew.
Tom

[white exec]

I thought you'd ask that...!

Good few 3.5-to-3.5 Citroen pipe unions fitted to BX, CX, XM...
Found these with a search on Parts - all are 3.5mm 'joiners', but all are NFP...
3-way Tee 96 027 373 (XM)
2-way straight 5 474 836 (XM)
3-way Tee 95 567 472 (BX FF brakes)
3/4-way K-shape 5 446 900 (BX RR susp)
3-way Tee 95 567 472 (BX FF susp)
2-way straight 5 447 189 (BX FF susp)

Easy enough to blank off any unwanted ports, by simply using a short length of 'plugged' 3.5mm pipe, and its screw-in, or even a bolt and small rubber stopper.

Did manage to find this, though...
http://www.cx-basis.de/leitungsverbinde ... 17096.html
2-way coupler (for CX, but all the same). New. Cheap. Available.
OE pt no 5 447 189.

Any of those pt nos above could be searched just by googling 'Citroen 5447189' etc.
No joy on any of them on Pieces de Rechange.
Those couplers/unions would normally be expected to last for ever.
That that last straight has been re-manufactured tells us something!


Hope helpful.

[xantom]

Thanks for that. The pipe is now replaced and the car is up and running. Got a front offside wheel bearing groaning at me but I've got the kit to fix that. I have a significant leak from the pump on my other Xantia, an automatic Mk2 1.9TD. It's from the joint between the body and top half. I've got the seal and I've got the pump off the car and in the process of cleaning the outside now. I'm having problems with the security bolts on the armour. The heads on mine look like circular domes with a small cylindrical stub protruding from the centre. I've used CitroJim's excellent guide to stripping these pumps before but the troublesome armour bolts on my previous pump adventure weren't like these. Does anyone know of a tool or a technique for getting these out? Fingers crossed and thanks.
Tom

[mickthemaverick]

Depending on what size your bolts are you can get a set of security screw bits that will do the job:

https://www.ebay.co.uk/itm/184979318089 ... SwEtBgD983

[xantom]

Hi, thanks for the reply. I'm okay for tools for standard security, hollow bolts. I've attached a photo to show you what I mean by 'dome' heads. I admit I'm at a loss on how to approach these things.

[mickthemaverick]

Sorry Tom no idea but someone who does know will enlighten us I'm sure

[white exec]

I can see standard torx head screws there, and a couple of slightly suspicious-looking straight-slot screws. Would not expect to see the latter at all . . . they just aren't used on our cars, so far as I know. They're already burred, which looks as if someone might have been there before.

The "domed" items don't look like assembly fixings at all; are you sure they're not just end plate location dowels? Could be wrong.

Re-assembling and re-sealing these pumps (with the full pukka seal kit) is a fairly specialist job, which any good diesel-specialist workshop would do, and for a fixed price. Might be worth looking at? In 2020 I had my Bosch inj pump on the 2.5 XM professionally overhauled (it had a leak) at a cost of just under €300.

[moizeau]

I'm with Chris on this one, never seen a slotted machine screw on a PSA part. Also the domed headed 'things', the only way they could be fixings is if they were the type that shears it's head on fastening. The plate with the slotted screws seem to be sitting on top of or part of the plate with the domed 'things' so would have to be removed first regardless.