Brake problems

FEDAK · Unread post by **FEDAK** » 21 Feb 2003, 13:01

Hi
I have a 97 1.9 TDLX Xantia Which recently has had all but the anti sink sphere changed (+ new LMH fluid) at my local Citroen garage. whilst the brakes will stop the car (and lock up) the pedal feels vague i.e. you have to apply more pressure than before to apply the brakes. The brake valve also makes a hissing noise when released.
Any ideas???
DAVE,
I DON'T WANT TO TAKE IT BACK TO THEM WITHOUT SOME CLUES AS TO THE PROBLEM. THE BRAKES WERE FINE AT FIRST IT JUST HAPPENED A FEW WEEKS LATER. I CHECKED THE PADS AND THEY'RE OK.
IS IT WORTH BLEEDING THE BRAKES??

Dave Burns · Unread post by **Dave Burns** » 22 Feb 2003, 00:11

You ought to go back and complain, if the job was done properly there should be no change in the braking of the vehicle.
A momentary hiss from the brake valve as the brakes are released is normal after a moderate to heavy application, hiss on release after light application is not.
Dave

blueboy2001 · Unread post by **blueboy2001** » 22 Feb 2003, 01:04

Sorry to butt in, but the mention of hissing caught my attention. My Xantia is hissing constantly every couple of seconds, for about a second, its definitely a hiss noise as opposed to a ticking sound which I initially thought it was. Could the brake valve be the root cause of this? Another symptom it has is its sat flat on its back wheels within 10 minutes of being parked up, which again I believe points to the brake valve.
Is the brake valve also known as the doseur valve? Where is it located on the car, is it a straightforward item to change?

Dave Burns · Unread post by **Dave Burns** » 22 Feb 2003, 01:30

Blue, Iv'e heard several early Xantias making this hissing sound, I think its to do with the flow distributor valve, unles the hissing is very loud, I wouldn't think there was a problem and would just treat it as a trait.
If this coincides with poor power steering or braking performance though I would be concerned.
Do you know the condition of the accumulator sphere, this might not be helping matters.
Down on the deck at ten minutes is not a good sign for the doseur (brake) valve as you are aware, it is situated on the bulkhead in the engine compartment, such as the brake pedal pushrod can activate it.
You will see it is not something a complete novice should attempt to change.
Not to imply that this is not within your particular ability but only you can be the judge of what is.
Dave

blueboy2001 · Unread post by **blueboy2001** » 22 Feb 2003, 01:47

Accumilator has been done by a garage about 6 weeks ago, I had originally thought that was the cause of the hissing.
It will often hiss for a good 30 solid seconds after its been started, then it goes to 1 second bursts about every 3 seconds. Nothing seems to be wrong with it as such, only complaint I've had is sometimes the brake pedal pulses slightly when the brakes are applied. They passed an MOT last week though.
As its passed its MOT I'm prepared to throw a few bob at it, It's having a visit to a Citroen specialist next week for a cambelt, I'll bite the bullet and get a new doseur valve thrown on as well. I'd be tempted to have a go myself, but my arm's in plaster at the moment so its out of the question.