Help. Rear Suspension wont go down and MOT tomorrow

citronut · Post by **citronut** » 21 Mar 2010, 10:28

the only thing with just fitting new pads is they will still be running at an angle, so you might not have the full braking presure on the disc, which in turn could still give you imbalance,

regards malcolm

cox377 · Post by **cox377** » 21 Mar 2010, 15:00

Hello guys I've managed to get back from work early and the sun is shining.

I've removed the rear wheels, removed the plate at the back of the caliper.

The discs are in good condition, the pad appear to be true to the disc and wearing evenly. I can't see anything white or obstructing between the caliper and the trailing arm. I hope I'm not missing something obvious.

Any ideas guys?

James

Xantidote · Post by **Xantidote** » 21 Mar 2010, 17:13

Well at least you haven't got to strip it all down - perhaps someone's already done the job in the past

As regards the rear brakes imbalance, bit of a problem. Were the discs nice and shiney, because unless you're regularly carrying weight in the back, I've found that the discs tend to slowly rust up over a few years. Every now and then I use coarse emery or the angle grinder on them.

I'd try bleeding the rear brakes, in case one side has a little air in the LHM, causing one side to come on a little more slowly. Changing the LHM last autumn, I was surprised to get several bubbles out of the offside rear, but car had just passed MoT without problem. Alternatively, could one of the caliper pistons be a bit lazy? If you were to remove each pad in turn, can you push/lever the piston back into the caliper without too much effort? Do both inner disc faces have same sort on shine, and likewise with the outer faces. One being much less shiney might suggest sticking/lazy piston

Post by **myglaren** » 21 Mar 2010, 17:20

With the GS, BX and Xantia I used to periodically load up the boot/loadspace with stupidly heavy weights to 'exercise' the rear brakes and keep them working or they would atrophy.

Do it with the C5 but only because there is almost always some pile of junk in the back, currently a pair of floorstanding speakers at around 100 Kilos and a toolbox that weighs nearly as much, plus other assorted toolboxes and other rubbish.
I have no idea if the C5 benifits in the same way but it can't hurt. The suspension always seems to benefit from being a bit overloaded anyway

cox377 · Post by **cox377** » 21 Mar 2010, 17:59

Hello guys,

I often carry in excess of 200KG in the boot so I dont think it's that, the discs did look shiney from every angle, it sounds strange but they looked spot on.

Regarding getting the pads out, do you remove the cover plate and then are they supposed to pull out backwards? Can I get the cylinder back in if the caliper are still in situe?

Just a thought, it's a bloody shame I didnt ask which brake was off,

Thanks Guys

James

Xaccers · Post by **Xaccers** » 21 Mar 2010, 18:10

Remove the plate, open the bleed nipple, wiggle the pads left and right to push the pistons back and then pull them out, if memory serves.

cox377 · Post by **cox377** » 21 Mar 2010, 18:12

Sounds good, thanks guys

I'll let you know how I get on.

ALl the best

JAmes

Xaccers · Post by **Xaccers** » 21 Mar 2010, 18:24

When you go for the MoT, leave the 200KG in the boot.

Xantidote · Post by **Xantidote** » 21 Mar 2010, 18:29

James:

Just remove the small dia bolt which holds dust cover in place - bolt also passes thro' the lug of each pad. Each pad has an "anti-squeal" shim between pad and piston. Make a note of orientation of shim when you remove it, or you'll be scratching your head later when refitting it. I apply light smear of copper grease to each shim on re-assembly.

Was only suggesting you push pads back into caliper, but if you were to remove them, maybe 1 pad at a time, & insert a thin block of wood (thickness to simulate a worn down pad), then you could apply brakes to check that the piston is doing it's job, moving out to press against wooden block. Wooden block/pad will prevent too much piston movement. Then push piston back into caliper, to refit the pad.

Myglaren:

I think your in-car entertainment system is a bit OTT. !00 kg speakers???

Post by **myglaren** » 21 Mar 2010, 18:45

Xantidote wrote:
Myglaren:

I think your in-car entertainment system is a bit OTT. !00 kg speakers???

If Only!

They are a 'spare' pair that my son-in-law has been borrowing for a couple of years. I have had them in the boot for a week now and can't face dragging them into the house and trying to get them up in the loft.
Might delegate daughter #3 for that task, strong as a horse

DaveW · Post by **DaveW** » 23 Mar 2010, 13:29

cox377 wrote:thanks for coming back to me Xac, so theoretically, if the caliper isn't hitting the disc then a new set of pads may be an option.

Damn this rain

James

Provided the discs are nice and shiny and the old pads have worn evenly - i.e. not wedge shaped.
Often the rear discs go manky after a while if the the car is driven with a light load - just the driver (and sensible use of the brakes) - because of the way the hydropnumatic system automatically adjusts the front to rear braking effort distribution.

Dave.

cox377 · Post by **cox377** » 24 Mar 2010, 09:26

As an update, I got a new dog and bone last night from Citroen, couldn’t get one from GSF they said main dealer only. Damn those sales guys looks more greasey that I do after working on the motor.

Got back under it last night and changed it over, the old only almost fell off both sides but the new one was a right ***** to get on, which I’m assuming is a good thing.

Regarding the brakes, I’ve noticed almost a wirring sound coming from the back when I’m braking, I noticed it over the last few days so it will be on the inspection list.

Maybe a good braking session will get things moving 

James

cox377 · Post by **cox377** » 27 Mar 2010, 12:06

Well, had the back end up in the air again. Took the pads out checked and replaced. I've bleed the brakes as well. Trouble is, with the ass in the air and no pressure on the suspension little came out. On the near side is came out really fast then didnt move much after that. The offside didnt move much at all.

I tried jacking the offside hub into the air to give it the impression it had weight in it and some more came out.. but not gushing. Should this be of concern?

Oh yeh and no air other than a few minute bubbles.

Much appreciated as always guys

James

citronut · Post by **citronut** » 28 Mar 2010, 11:18

Jame's
if the suspension is at full hight this is enough to give full fluid flow whilst bleeding the rear brakes, you dont need weight on the rear as well,

try removeing that bleed kniple and clean it through/out, as maybe it's full of crap,

Steve wrote
"a pair of floorstanding speakers"

hope you have cut a nice and neat apropriate sized holes in your parcle shelf Steve,

regards malcolm

cox377 · Post by **cox377** » 28 Mar 2010, 16:06

Hello Malcolm,

Thanks for coming back to me. I've just had the wheel off again and removed the nipple completely. Cleaned and returned it. There was fluid coming through the pipe but at a very very slow rate. I removed the nipple completely again with the engine running and hit the brakes, after continual squeezing fluid appears but not gushing.

Dad said it was the same the otherside yesterday.

Is there a sensor that could be restricting the braking at the back, that maybe at fault?

Many thanks

James