Definitely brake(doseur) valve??
Moderator: RichardW
Definitely brake(doseur) valve??
Hi Everyone,
having had the car(Xantia 1.8 estate ,8 valve) for about 5 weeks now and spent a lot of time ,and a few ££`s too ,I`ve finally come to the conclusion that my "pulsing pedal" problem is due to a failing brake valve - or is it??[?][?]
To recap on what I`ve done: replaced accumulator sphere; freed-up the rear height corrector and manual override mechanism and adjusted same to correct height;replaced both rear suspension spheres;performed cit-aerobics and bled both front and rear brakes more than once (and fitted a new battery and front droplinks as well - though these are unrelated to the braking problem!)
I haven`t yet replaced anti-sink sphere but doubt if this would be responsible for my problem.[?][?]
All discs and pads and run-out look ok but there is some evidence of rear discs not being "polished" by the pads but I put this down to height selector/corrector sticking and rear end generally having a mind of it`s own ,which may have influenced brake -line pressure - I`m talking of this going on for some time before I got the car - and of course the pulsing pedal may also have had more effect on the rear brakes.[?]
These are just assumptions based on my limited knowledge of the Citroen system! - Incidentally, the front spheres were just renewed before I bought the car.
There is a slight squelching sound from brake pedal ,though I`m not sure what is "Normal"
I haven`t checked the lhm return from the valve ,could anyone tell me which one it is?( I have checked the thin return but there are two - the second disappears behind the LHM tank)
I`m sorry this is such a long drawn- out posting - I just wanted to get all my thoughts down at once[:I]
The haynes manual says there is a repair kit available - has anyone any experience of this ,or should I just go for the new valve?[?]Price could come into the equation.
Also , I presume it`s not too difficult to remove/refit[?]- Being an 8-valve there is more room to work in I think. And is there anything I should look out for/or have available for the job[?]
Finally, there is a Rhythmic pounding noise (like a distant helicopter)which seems to be coming from under the battery and which I don`t recognise ,is this normal and am I being paranoid or is it another fault[?](I don`t know which answer I`d prefer!)
I will appreciate any advice and tips on any/all of the above.[:)][?]
having had the car(Xantia 1.8 estate ,8 valve) for about 5 weeks now and spent a lot of time ,and a few ££`s too ,I`ve finally come to the conclusion that my "pulsing pedal" problem is due to a failing brake valve - or is it??[?][?]
To recap on what I`ve done: replaced accumulator sphere; freed-up the rear height corrector and manual override mechanism and adjusted same to correct height;replaced both rear suspension spheres;performed cit-aerobics and bled both front and rear brakes more than once (and fitted a new battery and front droplinks as well - though these are unrelated to the braking problem!)
I haven`t yet replaced anti-sink sphere but doubt if this would be responsible for my problem.[?][?]
All discs and pads and run-out look ok but there is some evidence of rear discs not being "polished" by the pads but I put this down to height selector/corrector sticking and rear end generally having a mind of it`s own ,which may have influenced brake -line pressure - I`m talking of this going on for some time before I got the car - and of course the pulsing pedal may also have had more effect on the rear brakes.[?]
These are just assumptions based on my limited knowledge of the Citroen system! - Incidentally, the front spheres were just renewed before I bought the car.
There is a slight squelching sound from brake pedal ,though I`m not sure what is "Normal"
I haven`t checked the lhm return from the valve ,could anyone tell me which one it is?( I have checked the thin return but there are two - the second disappears behind the LHM tank)
I`m sorry this is such a long drawn- out posting - I just wanted to get all my thoughts down at once[:I]
The haynes manual says there is a repair kit available - has anyone any experience of this ,or should I just go for the new valve?[?]Price could come into the equation.
Also , I presume it`s not too difficult to remove/refit[?]- Being an 8-valve there is more room to work in I think. And is there anything I should look out for/or have available for the job[?]
Finally, there is a Rhythmic pounding noise (like a distant helicopter)which seems to be coming from under the battery and which I don`t recognise ,is this normal and am I being paranoid or is it another fault[?](I don`t know which answer I`d prefer!)
I will appreciate any advice and tips on any/all of the above.[:)][?]
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Thanks to the three of you so far - I will have a (much)closer look at those calipers soon. I think I had been ignoring "normal" problems and looking for the special Citroen ones.IE I had my head in the sand.[:I]Typically, I hadn`t read that particular posting,but I have now.[B)]
Any other tips will be appreciated[:D][:D]
Any other tips will be appreciated[:D][:D]
Sorry to come back with the same old problem,but another week has gone by and I still haven`t completely solved the pulsing pedal.( I might actually get to drive somewhere one of these days)
I`m pretty sure it`s not the rear calipers , all appears fine now - must have cured it with my many ministrations on the rear suspension and brakes(bleeding).
I also removed the spring from the plunger at the rear of the brake pedal - and I could still feel the pulsing ,but the frequency seemed higher which made me think again about the possibility it may still be warped discs although I thought I`d checked these properly.- I will look again.
This time I also got round to checking the LHM return from the brake control valve (2 pipes) and it was negligible - so I guess I can rule out the valve(??)
This has been and still is a very baffling fault ,no less so because it appeared to have disappeared only to come back again,and again.
My best description: It feels like the brakes grab and then partially release ,so I have to increase pressure as I near my stopping point or I could find myself overshooting.Removing that spring gave more control and I felt it less but I put it back in because it didn`t feel right(Too solid)
Perhaps this hint might help:I actually got in touch with the previous owner (on a different matter) and he said there was never any pulsing ,and since then it was kept by a repair garage who just put the two front spheres on and changed the oil!(Oh and it was MOT`d)
Perhaps the problem will just go away if I stop thinking about it*@!!&*
I`m pretty sure it`s not the rear calipers , all appears fine now - must have cured it with my many ministrations on the rear suspension and brakes(bleeding).
I also removed the spring from the plunger at the rear of the brake pedal - and I could still feel the pulsing ,but the frequency seemed higher which made me think again about the possibility it may still be warped discs although I thought I`d checked these properly.- I will look again.
This time I also got round to checking the LHM return from the brake control valve (2 pipes) and it was negligible - so I guess I can rule out the valve(??)
This has been and still is a very baffling fault ,no less so because it appeared to have disappeared only to come back again,and again.
My best description: It feels like the brakes grab and then partially release ,so I have to increase pressure as I near my stopping point or I could find myself overshooting.Removing that spring gave more control and I felt it less but I put it back in because it didn`t feel right(Too solid)
Perhaps this hint might help:I actually got in touch with the previous owner (on a different matter) and he said there was never any pulsing ,and since then it was kept by a repair garage who just put the two front spheres on and changed the oil!(Oh and it was MOT`d)
Perhaps the problem will just go away if I stop thinking about it*@!!&*
Thnks for thoughts guys - Have changed the acc sphere recently.
The whirring sound is not connected to this fault and is when standing still (more a beating sound)
I am leaning towards the discs,but the frequency seems too low to me (I.E. the pulse covers more than one rev of any wheels)
I will recheck them thoroughly though as I`m running out of ideas!
The whirring sound is not connected to this fault and is when standing still (more a beating sound)
I am leaning towards the discs,but the frequency seems too low to me (I.E. the pulse covers more than one rev of any wheels)
I will recheck them thoroughly though as I`m running out of ideas!
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Guess what? - yes, when I went for morning papers there was not a trace of the dreaded pulse!
I`m trying to think what I did last and it was just replacing the pedal spring and taking out the nylon bush (which conveniently fitted),and checking the LHM return flow , neither of which should have had any affect. - It was raining though.....
Anyway I do expect it to come back again,so maybe I`ll just change the brake pads for the fun of it ,even though they have 6-7 mm on fronts and 8-9mm on rears.
Thanks Stephen for that confidence booster,but I`d certainly prefer to be driving it than lying underneath it - taking necessary precautions of course!
I`m trying to think what I did last and it was just replacing the pedal spring and taking out the nylon bush (which conveniently fitted),and checking the LHM return flow , neither of which should have had any affect. - It was raining though.....
Anyway I do expect it to come back again,so maybe I`ll just change the brake pads for the fun of it ,even though they have 6-7 mm on fronts and 8-9mm on rears.
Thanks Stephen for that confidence booster,but I`d certainly prefer to be driving it than lying underneath it - taking necessary precautions of course!
Harry, try if any help here : Overhauling the brake valve
Thanks again Anders,I may yet have to get at that valve.
I`m hoping it won`t be necessary ,but I`ll just bite the bullet if/when it comes to it.
The sinking I think might fall into "normal" parameters now - about 3cm or so all round?? And it doesn`t seem to hit the stops no matter how long it`s left - max 3 days so far.
I take it that the repair kit is readily available?
Here`s hoping that ,by some magic,it has been cured - but in all my experience of cars ,faults rarely disappear!
I`m hoping it won`t be necessary ,but I`ll just bite the bullet if/when it comes to it.
The sinking I think might fall into "normal" parameters now - about 3cm or so all round?? And it doesn`t seem to hit the stops no matter how long it`s left - max 3 days so far.
I take it that the repair kit is readily available?
Here`s hoping that ,by some magic,it has been cured - but in all my experience of cars ,faults rarely disappear!