Leak, Rear T-thingy :(

[Threepointoveesix]

Hey Forum

My XM 3.0 24V (s1) is leaking rather profusely from the top of the rear axle tube usually after braking (no leaking while rising), and it appears to come from a small T-distributor (on the top of the rear axle tube), which in turn seem to be connected to the brakes.

My first impulse is to replace the entire setup (pipes, nuts and connector/distributor), but does anyone know the measurements of the pipes? (one goes right up to the primary brake-cylinder)

And where to get the T-thingy?

Can I solve it but replacing the rubber-seals?

I hope someone can help. Citroen Denmark is no help.

Best regards

Kenneth, Denmark

[noz]

Hi Kenneth,

The hydraulic pipes are prone to rusting in this area since it gets wet but never really gets dry again.

It sounds like you need to replace one or more pipes. However, the tee-piece usually lasts for the lifetime of the car. I have never heard of one rusting through. Although the leak may look like its coming from the tee it is more likely to be coming from the point just where the pipe enters the end connector. The dirt and water collects in the recess and rots the pipe at this location. If you remove the burst pipes from the tee-piece I'm fairly sure the tee-piece will be reusable.

The pipe size for most of the braking circuit is 3.5mm (OD).

If you removed the leaky pipe and measured the length then I'm sure someone in the UK could make a pipe up and send it in the post. I have a pipe making kit and would be more than happy to do that for the cost of the materials and postage if you're struggling in Denmark.

Let us know how you get on or if you want to have a pipe sent over.

Cheers

noz

[Threepointoveesix]

Thank you very much for the advice Noz

I had the car on a lift today, and it's not at the tee-piece as I previously assumed (the LHM just crept in that direction). It's the left-rear brake-pipe going from the tee-piece to the disc, the pipe has corroded in a small plastic-clip holding it onto the rear axle-tube. So things just got alot simpler Now I just need to figure out how long the pipe is (its quite intrigate bends and coiling make it hard to measure). I have found a shop here in DK which can make affordable pipes on measurements.

Does anyone know the full length of this pipe? (left rear brake-pipe)

Thanks again

Kenneth, Denmark

[Peter.N.]

Hi Kenneth

If it goes all the way to the front its better just to replace the section that has corroded. You should be able to get two ends and a coupler, you can here anyway from Plieades in Cambridgshire. I joined mine where the pipes leave the subframe to run along the chassis, its easier to get to there. It is a long and complicated run all the way to the front.

Peter.N.

[Andmcit]

The car's not going anywhere with a leaking high pressure pipe so bite the bullet and remove it to measure using string and allowing routing of its replacement. I seem to recall Citroen have a full spec of all the high pressure and return pipes on their system and that'd include the length? Alternatively try the string measurement first before removal of anything...

Andrew

[Threepointoveesix]

The "string theory" is actually a good idea I'm very close to having detached the left.rear brakepipe from the car, and I will use that as my point of reference. My problem right now is stuck, rusty and fragile pipenuts, I'm dead-scared of being too rough as they might break.

I'll jack the car up this afternoon and give it a go :S

Kenneth

[noz]

Hi Kenenth,

When Citroen build the car they use a type of tubing nut which is mild steel, 8mm across the flats and is "hollow" for the depth of the hex part of the nut. The steel/steel interface between the tubing nut and pipe is where the majority of the corrosion takes place. The "hollow" provides a nice pocket for moisture and salt to accumulate in order to promote the rusting process. In addition, the "hollow" part of the nut is just behind the hex where, of course, all of the forces are exerted when undoing the nut with a spanner or ring key. A cynical person may come to the conclusion that Citroen intended these to be scrapped entirely once rusted.

There are only two methods I know of to remove the tubing nuts from the Tee-piece:

1. Cut the remainder of the pipe off just above the tubing nut (the pipe is scrap anyway). Now you have access to put a socket over the end of the tubing nut. Use a SIX-pointed socket on the nut and NOT a 12-pointed which are the more usual type. The 12-poters don't have enough contact area and will simply round the corners. Be warned.

Or

2. Cut the remainder of the pipe off just above the tubing nut (the pipe is scrap anyway). Now heat the tubing nut with oxy-acetylene until cherry red (protecting everything else around the joint from the flame). Using a pair of mole grips undo the tubing nut from the tee-piece. It usually loosens no problem once heated. The tubing nut is so flimsy that it is possible to heat it up until glowing red without heating the tee-piece up too much and destroying the seals in the adjacent connections.


Only in a very few number of occasions have I found that I can remove a tubing nut with the pipe intact using the 6-pointed ring spanner with the gap in the ring. MOstly however, even when that special spanner gets the tubing nut rotating in the tee-piece, the rust holds the pipe firmly to the tubing nut and if you keep rotating the tubing nut you simply twist and then shear the tubing.

Whilst its not my intention to try to scare you its worth knowing what to expect before you start. Forewarened is forearmed as the old cliche goes.

Best of luck.

Cheers

noz

[Peter.N.]

...or slide a larger nut over the top and weld it on...that's how I got mine off.

[Threepointoveesix]

SUCCESS

I managed to loosen the pipenuts using a self-locking wrench. The faulty brakepipe is now replaced with a copper-nickel pipe with brass nuts (no pun). And the brakes work properly now, even though it took some time before I figured out how to bleed the system

I considered the hydraulic system the biggest challenge, now I just have to perform the simpler repairs (parking brake, lower right ball-joint, rusty jack-stand points rear both sides)

Thank you all for helping me out

Best Regards

Kenneth, Denmark

This post has been edited by Threepointoveesix on August 28, 2008 12:44 pm

[citroenxm]

WOW - Is that black!?

Very sexy S1 24v - shame about the after market alloys. You just CAN NOT beat the standard 24v S1 alloys, or later SE alloys...

Nice motor!

Rgds
Paul