Xantia MOT

[froggy]

Hi, my S2 Xantia failed the MOT on, ' service brake has no recorded effort at a wheel Offside Rear'. Iam wondering should I start by bleeding the rear brakes? cheers Terry.

[peter306]

Hello, the rear brakes on the BX and Xantia can seize up through lack of use, if there is rarely any weight in the back they don't get used much.
I would remove the wheel and check that the pads are moving, if not then it's caliper off and hopefully it can be cleaned up.
Also ckeck for corrosion between the caliper mount and trailing arm.
If non of that is the case then bleeding the brakes wouldn't harm.
I'm sure that someone with more knowledge than me ( CitroJim, Alasdair and many others) will be along soon
Have fun Peter

[CitroJim]

Perfect advice Peter

Have a look at the wear pattern on the disc braking surface on the failed side. You may find the surface rusty and contact from the pads only in a very small area. This is a sure sign of corrosion between the trailing arm and caliper body, thus pushing the caliper out of square in relation to the disc. You will find the pads might be worn 'keystone' shaped...

There's lots of threads on here about how to successfully resolve this issue. You need to be very careful not to shear off the high-tensile bolts

Just as an addition, if all else fails to bring about adequate performance then check the rear spheres.

[froggy]

The disc is in good shape, everything in line. when I tried to bleed the brake, there was very slow flow of fluid! is the caliper my next port of call.

[RichardW]

Did you bleed it engine running, pedal wedged down?

Odd that it is no recording any effort if the disc looks OK - normally you would expect the disc to look like it is not working. TBH it's unlikely to be the caliper - I had one where the pads were so rusted in I had to saw them in half to get them out, but it all freed off nicely. I would get the pads out and give them a good clean up and hopefully that will be enough to get it going.

[CitroJim]

Also, you need to bleed with the suspension on high and with a load on it to ensure you get a good flow, If the suspension is unloaded then you will indeed get very little flow.

I used to support the car on axle stands at the back, take the rear wheels off, start up, set suspension on high and then put a trolley jack under the suspension arm to load it. Then I bled.

You need to bleed at least 500mL out as the pipes are very long to the rear calipers. From rear suspension, to the dosuer and back again so twice the length of the car.

Rather than waste LHM, if clean, save it and pour it back into the reservoir. Also, you can use a long length of plastic bleed pipe and bleed directly back into the reservoir!

[froggy]

cheers everybody.

[froggy]

cheers, job done, many again to all, Terry.

[CitroJim]

cheers, job done, many again to all, Terry.

Magic! What did you do Terry?

[froggy]

Hi Jim, axle stands on the rear of the car, loaded the suspension arm with a trolley jack (great advice) bleed about 500ml of LHM. finished up with some citraerobics, job done, many thanks again. Terry.

[CitroJim]

Hi Jim, axle stands on the rear of the car, loaded the suspension arm with a trolley jack (great advice) bleed about 500ml of LHM. finished up with some citraerobics, job done, many thanks again. Terry.

Excellent

[froggy]

Hello , WELL, the car passed the MOT, excellent, but, yesterday the rear brakes did'nt seem to be working, the back of the car lifting on braking. I checked, same as before one of the rear brakes working the other, not. This morning replaced the anti sink sphere, bled the brakes, all working fine, result I thought, but no. Just jacked up one side of the car, broom depressing the brake , and no brakes one side! but the other side works! I have no idea what to do next? cheers Terry.

[Rp0thejester]

Cheers Terry? Is that an inuendo or a euthphormism?

[CitroJim]

I think I'd try a replacement caliper Terry...

[froggy]

Thanks Jim.