Strange problem with XM brakes

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tonyg
Posts: 28
Joined: 21 Jun 2003, 04:06
Location: United Kingdom
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Strange problem with XM brakes

Post by tonyg »

Hi
I have been having a strange problem with my old XM. When I first drive it, if I stop at a junction and hold the car on the footbrake for 10-15 seconds the pressure regulator starts clicking more rapidly (1-2 every second), the STOP warning light comes on and so does the "warning low hydro pressure" display message. If you put the car into park and let go the footbrake, the warning light goes off, put the car park into drive again and hold it on the footbrake and it's fine. Also non of this happens if you go more than 1-2mins before stopping first time. Any ideas why this is happening?
Some more info. The car has a FSH, all new spheres (except acculumator) 5K ago, plus hydroflushed at the same time as the sphere changes. The car rises up very quickly, goes really smoothly, although I think that maybe it's a little hard at the front. The accumulator has just recently started going, with the regulator clicking once every 7-8 seconds whilst the car is running at idle at normal ride height. I'm thinking of changing it. Do you think that changing the accumulator sphere might cure my problem?
Also just my personal opinion. The phase II seems vastly better than the phase I XM. All the electrics work on my phase II and hardly any seemed to on my last phase I! Low mileage XM phase II's are great value now too, although rare, I paid £1000 for mine a year ago, we've done 10K already and it's in fanastic condition. Aircon, cruise control, heated seats, what more could you want!
tony
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AndersDK
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Post by AndersDK »

Tony -
I'm pretty sure this is caused by a flat accumulator sphere.
The reason is that if the accumulator sphere only has very little gas left - it will very quickly be "filled" with pressure - but also very quickly runs "dry" on spare pressure.
It's like trying to pressurise a bottle of water with only a few mm of air left at top.
A new sphere works like the same bottle with only a few mL's of water on the bottom - the rest filled with air - easy to pressurise - and holds lot's of pressurised air.
See also this thread :
http://www.andyspares.com/discussionfor ... IC_ID=4169
tonyg
Posts: 28
Joined: 21 Jun 2003, 04:06
Location: United Kingdom
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Post by tonyg »

Hi Anders
Thanks for the info. Sounds pretty much what I expected. Off to change the accumulator as soon as I can prize the XM off the wife! and I thought it was my car.
tonyg
NiSk
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Post by NiSk »

If this is the first time the accumulator sphere has been changed, its not just your wife you will be having trouble prising off - accumulators are notorious - just getting a grip on them is the biggest problem. If you have A/C then you haven't much room to weild anything down there. I find that a blunt metal chisel on the rim weld and a hand sledge usually fix it.
//NiSk
tonyg
Posts: 28
Joined: 21 Jun 2003, 04:06
Location: United Kingdom
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Post by tonyg »

Hi NiSK
Thanks for the advice but I live on 5 miles from Vantage Citroen (huge range of citroen parts - but more expensive than Andyspares). They change spheres for £10 while you wait, with the correct tool. No point doing it youself for that money! Yes there is not alot of room to do anything under the bonnet of a XM V6.
Tony
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