Still a sinker!!

This is the Forum for all your Citroen Technical Questions, Problems or Advice.

Moderator: RichardW

Post Reply
xantia sx auto
Posts: 89
Joined: 19 Apr 2010, 08:01
Location: chichester
My Cars:

Still a sinker!!

Post by xantia sx auto »

Hi, I've just changed the regulator sphere and the car rarely ticks now and if i sit in the boot and do the test it rises fine, but, overnight she's still a sinker! if i start up wait for stop light to go sometimes i start off and there are no breaks till i press hard then it nearly puts me through the windscreen! it did this before i changed the accumulator too but I was hoping it'd be cured now!!! perhaps i'm not waiting long enough but it seems top take ages to rise if i put it down to bottom setting and won't even start rising till i put it on highest!
there are no lhm leaks and she drives fine the sinking does not bother me really but it's just annoying as i know it should stay up now and i have to wait for it to come up before moving off!
anyone have any ideas?
User avatar
Xaccers
Posts: 7654
Joined: 07 Feb 2007, 23:46
Location: Milling around Milton Keynes
My Cars:
x 184

Post by Xaccers »

Replace A/S sphere (you know you should), and bleed the rear brakes.
Also check the rear calipers while you're at it for corrosion build up (like limescale) between the arm and the caliper. If found, remove caliper and chip off limescale. Refit caliper with grease or thin membrane to prevent regrowth.
1.9TD+ SX Xantia Estate (Cassy) running on 100% veg
1.9TD SX Xantia Hatchback (Jenny) running on 100% veg for sale
Laguna II 2.0dCi Privilege (Monty)

DIY sphere tool
xantia sx auto
Posts: 89
Joined: 19 Apr 2010, 08:01
Location: chichester
My Cars:

Post by xantia sx auto »

Got the car up on stands yesterday and had a look, I can't find this 9mm pipe that goes into the a/s sphere, it just looks like the other spheres, I took the pad cover off the calip[er and got rid or the dust and chunks of rubbish, don't know where u mean the limescale is, couldn't see any, I put a tube on bleed nipple and got my mrs to pump the pedal but only a tiny dribble of fluid came out, is there a certain method to doing this as it's not working like any other car i've done!, the calipers are very different, usually they have 1 piston that slides both halves but this is a big solid lump with 2 pistons in, i was going to change the disc as it's slightly warped but it looks so hard to remove the caliper compared to other cars as it has a solid pipe going in so i'm not going to bother! anti sink sphere would be too hard for me to do so that's not an option at the mo, so let me know how to bleed the rear breaks as i can do that once i know how!!!
many thanks
addo
Sara Watson's Stalker
Posts: 7098
Joined: 19 Aug 2008, 12:38
Location: NEW South Wales, Australia. I'll show you "Far, far away" ;-)
My Cars: Peugeot 605
Citroën Berlingo
Alfa 147
x 93

Post by addo »

To bleed the brakes you need a good accumulator sphere.

Start and run the car for a minute while it pumps to "service high", then shut it off. Jack up its rear and place it on stands under the subframe. Remove the back wheels. With a trolley jack or similar, lift the trailing arm until it starts to just affect the rear stands.

Now crack the bleed nipple while a helper holds steady pressure on the brake pedal. Don't pump the pedal, just hold it there. Nip the bleeder up when fluid runs fresh and green, and do the other side.

Front is similar; place the trolley jack cup under the balljoint nut with a piece of scrap wood to pad the threads.
xantia sx auto
Posts: 89
Joined: 19 Apr 2010, 08:01
Location: chichester
My Cars:

Post by xantia sx auto »

oh forgot to say, i left the car on highest setting over night and it has not sunki at all, is this good!?? what is the setting really for? can you drive like this? and the setting between middle and high what is that for?
cheers
xantia sx auto
Posts: 89
Joined: 19 Apr 2010, 08:01
Location: chichester
My Cars:

Post by xantia sx auto »

addo wrote:To bleed the brakes you need a good accumulator sphere.

Start and run the car for a minute while it pumps to "service high", then shut it off. Jack up its rear and place it on stands under the subframe. Remove the back wheels. With a trolley jack or similar, lift the trailing arm until it starts to just affect the rear stands.

Now crack the bleed nipple while a helper holds steady pressure on the brake pedal. Don't pump the pedal, just hold it there. Nip the bleeder up when fluid runs fresh and green, and do the other side.

Front is similar; place the trolley jack cup under the balljoint nut with a piece of scrap wood to pad the threads.
so the suspension needs to be on high?
User avatar
Xaccers
Posts: 7654
Joined: 07 Feb 2007, 23:46
Location: Milling around Milton Keynes
My Cars:
x 184

Post by Xaccers »

xantia sx auto wrote:oh forgot to say, i left the car on highest setting over night and it has not sunki at all, is this good!?? what is the setting really for? can you drive like this? and the setting between middle and high what is that for?
cheers
High and low are service levels and should not be driven in as you have no suspension movement, on high you stress strut tops etc, and on low you can ground.
The one up from normal is meant for traversing obsticles such as a deeper ford or debris, at dead slow speed. As the system ages, the intermediate setting seems to turn into the high setting anyway.

I don't put the car on high when bleeding brakes, I just have the engine idling.
1.9TD+ SX Xantia Estate (Cassy) running on 100% veg
1.9TD SX Xantia Hatchback (Jenny) running on 100% veg for sale
Laguna II 2.0dCi Privilege (Monty)

DIY sphere tool
xantia sx auto
Posts: 89
Joined: 19 Apr 2010, 08:01
Location: chichester
My Cars:

Post by xantia sx auto »

i thoght of doing that but don't really like the idea of having the car running on stands! i know what i need to do now, thanks,
wanna buy a xantia!?
DoubleChevron
Posts: 622
Joined: 22 Sep 2003, 18:06
Location: Australia
My Cars:
Contact:

Post by DoubleChevron »

C'mon guys ... You should know this one :)

This is normal behaviour for a Xantia with a 6&2 pump. It's anti-sink valves are obviously leaking and allowing it to sink. As there is only 2 little weeny cylinders of the HP pump devoted to the brakes/suspension, it'll take a bloody enternity to lift and pressure the brakes. Proper pre PSA era Citroen instantly have brakes the second the motor starts due to the priority of the hydraulic circuits and high capacity system pump.

With the Xantia you MUST, must wait for the car to fully pressurise and lift before you move off. If you do not do this you will have NO BRAKES .... Until you suddenly build up enough pressure, at which point it'll throw you through the windscreen as your standing on teh brakes in panic :twisted: :P

seeya,
Shane L.
'96 Big BX 2.1TD exclusive slugomatic (aka XM)
'85 CX2500 GTi Turbo Series II (whoo hooo)
'96 Xantia VSX slugomatic (sold !!)
and of course, lots of old Citroens, slowly rusting away in pieces ;)
User avatar
CitroJim
A very naughty boy
Posts: 49534
Joined: 30 Apr 2005, 23:33
Location: Paggers
My Cars: Bluebell the AX, Polly the C3 Picasso, Pix the Nissan Pixo, Propel the duathlon bike, TCR Pro the road bike and Fuji the TT bike...
x 6163
Contact:

Post by CitroJim »

xantia sx auto wrote:i thoght of doing that but don't really like the idea of having the car running on stands! i know what i need to do now, thanks,
wanna buy a xantia!?
There's no risk if you take sensible and normal precautions.

The rear brakes can be bled with the engine not running if the anti-sink sphere is in good nick.

Sinking at the rear is normally caused by flat corners and has nothing to do with the condition of the anti-sink sphere. Desipte what it's called it has nothing to do with sinking (anti or otherwise). It is in fact, a rear brake accumulator used to store a reserve of pressure for rear brake application when the engine isnot running and main system pressure is low enough to shut the anti-sink valve. The only effect it may have on sinking is that it may help to ensure the prompt closing of the anti-sink valve.

"Limescale" is a buildup of corrosion between the alloy of the rear calipers and the steel trailing arm. This corrosion can push the calipers out of line and cause the pads to wear wedge-shaped. The calipers need to come off and have the corrosion (which looks like limscale) chipped away with a sharp cold chisel)
Jim

Runner, cyclist, time triallist, duathlete, Citroen AX fan and the CCC Citroenian 'From A to Z' Columnist...
Post Reply