Xantia 1.8 lx "pulsing pedal"

harryb.48 · Post by **harryb.48** » 03 Aug 2004, 04:00

I have just bought a Xantia 1.8 ,8 valve estate with the dreaded "pulsing pedal " problem which I have just read about ,but unfortunately,no explanation was given can anybody explain this problem.
I also seem to have the ticking noise from centre sphere,is this related or a separate problem?
I`ve already diagnosed that I have loose anti -stay rods on both sides
due to the low-speed rattle/thump.
This is my first experience with a xantia ,have I bought a dud!??
The dealer(yes dealer )I bought it from had just mot`d it and had changed the two front spheres , otherwise it handles and sounds good (except for above noises!)
Plse help

AndersDK · Post by **AndersDK** » 03 Aug 2004, 04:18

Dont think you've got a lemon.
The ticking noise is coming from the hydraulics system regulator, because the main accumulator sphere has run flat of precharge gas.
It's the sphere located down on engine block, denoted the main accumulator sphere.
And yes - it's related to the pulsing brake pedal [;)]
This sphere and the droplinks are cheap items - and easy to replace.

davethewheel · Post by **davethewheel** » 03 Aug 2004, 05:15

my Xantia has had a rattling noise from one of the drop links since i,ve owned it approx 2 years, i keep thinking next mot it will fail then i will fix it but it never does, like anders has said its an easy fix

TheWorker · Post by **TheWorker** » 06 Aug 2004, 01:23

stop calling it a Xantia, its xantia

wrinklet1 · Post by **wrinklet1** » 06 Aug 2004, 02:27

I have the same problem as yourself with the 'pulsating brake', I have done the citrobics several times, the pulsating comes and goes back again at random.I have replaced the accumalatore sphere,done a hydroflush, The pulsating comes and goes as quick as it comes.I wondered if it could be related to either resistance from the handbrake cable that may need adjustment. And yes I know it's supposed to be self adjusting Or, something to do with the back brakes with them being interconnected with the rear suspension.
No one can say that they actually know what causes the pulsating problem OR CAN THEY????
Paul

AndersDK · Post by **AndersDK** » 06 Aug 2004, 02:55

Nouuu I cant Paul, but at least you've tried the main suspects [:I]

wrinklet1 · Post by **wrinklet1** » 06 Aug 2004, 03:55

I wondered if it could be the main brake dosiuer (however you spell it)valve. I presume its basically a barrel, that moves when you put your foot on the brake peddle, releases the pressure into the circuits to the pads. I thought it could be that, that could be sticking or worn and allowing it to 'wobble' with the pressure causing it to vibrate and therefore make a pulse within the hydraulics????
Paul

nick · Post by **nick** » 06 Aug 2004, 04:06

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by wrinklet1

I have the same problem as yourself with the 'pulsating brake', I have done the citrobics several times, the pulsating comes and goes back again at random.I have replaced the accumalatore sphere,done a hydroflush, The pulsating comes and goes as quick as it comes.I wondered if it could be related to either resistance from the handbrake cable that may need adjustment. And yes I know it's supposed to be self adjusting Or, something to do with the back brakes with them being interconnected with the rear suspension.
No one can say that they actually know what causes the pulsating problem OR CAN THEY????
Paul
<hr height="1" noshade id="quote"></blockquote id="quote">
In the case of my Xantia it was simply air in the rear brake lines. The pulsing began a few months ago and steadily got worse until the point it was intolerable - it pulsed so badly that if I let my foot rest on the pedal it would bounce my entire right leg up and down by about 4 inches. I bled the rear brakes last week and it has completely stopped the pulsing. I'm not surprised it was bad, judging by the amount of air that came out the pipes must have been nearly 50 % full of air.
I think it originates from when I replaced a couple of spheres last autumn.I did Citerobics numerous times but this doesn't seem to prevent any residual air bubbles from slowly collecting in the brake lines. I also have a couple more spheres coming up for replacement soon and I suspect the nitrogen is slowly leaking out of them and further adding to the bubbles in the system.
Nick

wrinklet1 · Post by **wrinklet1** » 06 Aug 2004, 04:10

Nick, did you get to the point that you pressed your foot onto your brake peddle so hard that you felt it was going to go through the floor because of the frustration? Mainly as stress relief?[B)]
Paul

nick · Post by **nick** » 06 Aug 2004, 04:19

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by wrinklet1

Nick, did you get to the point that you pressed your foot onto your brake peddle so hard that you felt it was going to go through the floor because of the frustration? Mainly as stress relief?[B)]
Paul
<hr height="1" noshade id="quote"></blockquote id="quote">
Oh yes ! To make matters worse it began last week to make what can only be described as a loud farting noise every time the pedal was pushed [:I] luckily I don't often carry passengers ......

wrinklet1 · Post by **wrinklet1** » 06 Aug 2004, 04:33

My brake peddle hasn't done a farting noise, but I have[}:)]

nick · Post by **nick** » 06 Aug 2004, 04:40

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by wrinklet1

My brake peddle hasn't done a farting noise, but I have[}:)]
<hr height="1" noshade id="quote"></blockquote id="quote">
Well at least now you have the option of blaming it on the car [:D]

AndersDK · Post by **AndersDK** » 06 Aug 2004, 06:44

Our on-line Citroen BX library service provider [:)] Bob Smith [:)] has the following Citroen document on the brakes doseur valve :
http://www.rwbsmith.plus.com/citroen2/Brakes/doseur.pdf
Xantia models suffers from the extra springy device inserted between pedal and the valve.
This spring is fitted to make the Xantia brakes pedal feel like the average car brakes pedal.
Remove it (replace it with a suitable spacer/nut), and you have the good old BX sharp brakes pedal feeling [}:)]
Known problems with the brake doseur valve, are the reputed rear brakes circuit leaking, the front rubber knob seal leaking and air trapped in the valve.
If the valve gross fails, it will give a high flowrate in the operational return hoses, when the pedal is NOT activated.
I suspect that the farting pedal sound (also wellknown from BX & CX) is a pre-stage for the gross leak failure.

nick · Post by **nick** » 06 Aug 2004, 16:42

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by AndersDK

If the valve gross fails, it will give a high flowrate in the operational return hoses, when the pedal is NOT activated.
I suspect that the farting pedal sound (also wellknown from BX & CX) is a pre-stage for the gross leak failure.
<hr height="1" noshade id="quote"></blockquote id="quote">
I'm hoping it was just the large amount of air that was causing this on mine, bleeding the brakes seems to have stopped it for now. If its leaking internally it doesn't seem that bad yet, the brakes still have some pressure when the car hasn't been started for 24 hours or so, and its not clicking too often when ticking over, despite the accumulator sphere being due for replacement soon.
Nick

AndersDK · Post by **AndersDK** » 06 Aug 2004, 18:24

Obviously I'm at fault if it helped bleeding the brakes [8D]