Rear Brakes (& Spheres?), Rear brakes almost non-existant

Hi can anyone help, on my 97 Exc Turbo (PETROL) there was no pressure being given to the rear callipers, Ive tried to bleed them but there is a crappy brown coloured LHM coming out eventually after loads of air but there still doesnt seem much effort going to the callipers... also the rear suspension drops to the deck everytime I start the car and then slowly rises again, and when I stop in traffic the car drops again, only to slowly rise... could the two problems be related??

I would be grateful for any advice..

Cheers

Steve

Do you loose LHM at all i.e. do u need to add up all the time? If not, the leak should be internal. The safest way to diagnose then is to disconnect one-by-one th return pipes on the top cover of the LHM tank and see if there's one that's returning too much liquid back. This will tell you were the leak comes from and you can trace it back to the leaking component.

After you bleed the brakes of an XM, it stops LEVEL on braking. The rear brakes on an XM easily take up air -don't know why- and keep it as the brake calipers are dead ends for the circuit. If the LHM u found there was awful, it means it has probably never been bled there and God knows what sort of gunk has been accumulated in the area -and even if u've added new LHM it can't go there-.

1.how do you know there was no pressure at the rear calipers? Do u know if there is pressure now, after bleeding?
2.how much time does the car need to rise after an overnight stop (can u count pls)
3. in traffic, I take it it's the rear dropping again, not all the car?
4. how much time between clicks of the pressure regulator (just in standstill, engine running, doors closed, no braking, normal height).

Let us know of those details please.
George

HI George, thanks for you reply, the pressure does seem do be a tiny bit better, but the callipers are not budging (ie, there is fluid coming out of the bleed nipple now, there wasnt before) the car doesnt drop much overnight its only when I start it up it drops immediately, then pumps up again after about 4-5 clicks approx, the car seems to click once every 45 secs or so once running... at a stop (for instance at traffic lights) the rear will drop almost to the bottom and then pump up again (as it does on start up), wierd isnt it?

Cheers

Steve

This post has been edited by 97exclusive on July 12, 2006 02:55 pm

1. While you are actually breaking to stop for a red light, but before coming to a standstill, do you feel the rear lifting up, as if the car had an extremely soft suspension?

2. *When* does the rear drop suddenly (speaking of traffic lights):

a. just once, as soon as you have come to a standstill, just after the breaking effort? or,

b. randomly, more than once, at any time while you are waiting for the light to turn green? If (, can you relate this behaviour to you putting pressure on the brake pedal?

George

As the rear brakes are worked from the rear suspension pressure it is not possible to bleed the rear brakes if the car is jacked up under the body and the wheels allowed to hang. In this state the rear height adjusting valves cut off all suspension pressure in an effort to get the wheels back to the correct ride height. Hence no pressure to bleed the brakes. To overcome this make sure that the suspension is set to maximum height position as this overrides the valves. Hope this helps!

Cassmo