Rear discs & pads on Xantia

imperial21 · Post by **imperial21** » 06 Aug 2011, 18:48

Hi
Just changed the rear tyres on my car and i thought i would check the rear pads at the same time, I found the O/S rear in bad condition, the rear inside pad is getting low but the outside is fine the disks are in bad nick also i have noticed that about 10% of the inner pad is nt touching the disk has corrosion on it.
Is it easy to change the rear discs ? Do i need a wind back tool for the caliper ? I think i may need to free the caliper up a bit as there is more wear on one side of the disc are they sliding calipers ?

Deanxm · Post by **Deanxm** » 06 Aug 2011, 18:53

They are twin piston callipers so one may be seized, they are easy to repace though, just push the pistons back with a little lever, discs are straight forward too.
Just watch if you take the callipers off they are in two halves held together by their mounting bolts so put the pad retaining bolt in and do it up before removing the callipers to prevent them coming apart.................the two halvesre sealed by an 'o' ring so its not the end of the world but you MAY need a new seal if they come apart.

D

imperial21 · Post by **imperial21** » 06 Aug 2011, 18:56

Thanks Dean, They dont sound to bad to do !

Deanxm · Post by **Deanxm** » 06 Aug 2011, 18:59

Na they are very easy really, just plus gas the hell out of anything you want to undo as its all steel and alloy mixed on the xantia.

D

Xaccers · Post by **Xaccers** » 06 Aug 2011, 19:11

Look down from above and check that the disc runs true through the caliper, corrosion builds up between the arm and the caliper pushing it off at an angle.
It's always a good idea to check when you're in that area with the wheel off.

Xantidote · Post by **Xantidote** » 06 Aug 2011, 19:20

Unless you tow, or carry heavy loads in the back, then the rear discs don't do much work, and corrosion tends to build up on the discs. I've cleaned mine up from time to time with an angle grinder. Discs lasted quite well nevertheless, and I only finally changed the rear discs when car was about 14 years old.

Citroenmad · Post by **Citroenmad** » 06 Aug 2011, 19:29

Yes as Xac says, check that the pads are wearing flat and not at a wedge shape, as this is what is caused by corrosion between the caliper and suspension arm, pad wear also seems accelerated by it too.

Very very easy to change the discs and pads though, as the handbrake is on the front there is no need to wind the pistons back either. I cleaned my C5s (exactly the same as Xantias) rear pads and discs up about two weeks ago as one was aquealing, took me about 15 minutes each side.

I didn't remove the calipers as mine were wearing flat, but you might want to remove yours and sand back any corrosion between it and the arm and put in a layer of copper grease to help it too.

imperial21 · Post by **imperial21** » 06 Aug 2011, 19:36

I tow a caravan & trailers so i will need to have good brakes ! I was surpised at how thin the discs are ! So do you think working the piston back and forward a few times should sort a sticky piston ?

Post by **CitroJim** » 06 Aug 2011, 20:42

If there is corrosion present and you need to remove the calipers pray be very careful in removing the caliper bolts.

They're high tensile steel and brittle so they just love to snap off...

Wire brush the treaded ends where they poke through the back of the trailing arm and douse liberally in Plus Gas. Allow to soak in for an hour or so, repeating the application occasionally.

Use a long breaker bar on the bolts but with only gentle pressure on the end. Don't put eye-popping force on them and go easy. Try doing them up a tad before trying again to undo them.

If they feel 'elasticky', indicating that the head and shaft is turning but not the thread, hold the pressure on gently and allow the threaded part to get the idea and let it unscrew itself via the twist you've put in the bolt shaft.

Go easy and you'll be OK...