Xantia - Brake Doseur Valve leak

[XantiaNonStarter]

The Stop light came on while driving my Xantia. Most of the LHM very quicky leaked out of the car onto the road. The leak is coming from the Brake Doseur Valve (photo attached.)

I've read through a few previous forum posts on this subject. Given how rapid the fluid loss was, what do you think the likely cause is:
- Seals inside the valve
- The rubber return pipe
- Or something else?

Thank you for any advice you can give.

[xantia_v6]

If it is leaking in the engine bay, then a split in a rubber return hose is most likely.

[davoxx]

Is that what the pedal presses? I've had one go and dump almost all my lhm. Its a PITA to change.

[Armidillo]

I had a leaking doseur return line on a Xantia Turbo CT - apparently the added heat from the turbo engine kills the rubber bits faster.

What was tricky was that the original Citroen hose had 2 layers. The inner layer split for a considerable length, while the outer layer looked fine. The LHM just ran out at the cut end, no matter how I tightened the hose clamp. Cutting off a short piece didn't help, I had to work along the hardened pipe until I finally got to a section still soft enough that I could push in a joiner without splitting the old tube, then graft in a new section (which not surprisingly was not double layer hose).

PS - check under the carpet on the driver's side. If the dreaded brake valve/doseur boot has split (& they all do eventually) then most of the missing LHM will be soaked into the carpet in the driver's footwell. The wetness you see may be a red herring.

[XantiaNonStarter]

Thank you everyone for your help. Armidillo, the carpet is dry. davoxx, yes it's the valve that the brake pedal presses.

I've got a little further. There are two rubber return hoses. The problem is with the top one. I blew into the other end of the hose and could hear it bubbling at the doseur valve end.

I topped up the LHM; the car had lost about a litre. I started the car and it started leaking again (even when the brakes were not being used.)

I am struggling to remove the top hose. It is secured with one of those Citroen metal clips (like the ones on hoses near the LHM reservoir) but is in a very inaccessible location. Does anyone have any tips on how to get this clip off? I can barely get to it.

[xantia_v6]

I think that you may need to unbolt the valve from the firewall and move it gently to get better access.

The spigot on the valve probably doesn't have a flare, so maybe you can just push the hose off.

[XantiaNonStarter]

Thanks xantia_v6, I have made a bit more progress with your help.

The two doseur valve bolts are undone. There are a couple of big rubber pipes (aircon?) in front of the valve which I have moved out of the way. I have withdrawn the valve from the bulkhead but can't really rotate in the same way others have described. I have removed the plastic clips on the LHM pipes to allow them to flex more.

So still can't get that metal clip off the doseur valve rubber pipe but working on it

[XantiaNonStarter]

I've got there unbelievably! Thank you everyone for your help.

I bought bullnose clutters and managed to get the metal clip off. The rubber pipe then came off but the brittle end broken off. I had to cut that off the doseur valve with a knife.

The newly shorten rubber hose then would not fit back onto the valve. I put it in a cup of hot water to soften the rubber and was then able to force it on. I've run the car a few times and so far there are no LHM leaks.

[Stickyfinger]

It is always nice when a tough/tricky job goes well........