Rear calipers are at a funny angle

[red_dwarfers]

I've got a list of jobs that need doing on the Xantia. I shall go into a bit more detail on my blog when I'm in the blog entry writing mood!

The problem we have is that the rear calipers are almost touching the disks which is down to corrosion between the calipers and trailing arm. I've not done the job before but I'll put money on the bolts that hold the calipers shearing due to the silly angle they're at.

So a shopping list:
Rear pads
Caliper bolts

Should anything else be replaced while I'm there? Brake bleeding was how I realised the problem existed.
I remember someone saying something about putting copperslip between the surfaces when putting it back together, did I remember rightly?
Any top tips for removing the caliper bolts?
Anything else I should note?

[reblack68]

I think the advice was to make a gasket out of thick polythene from a fertiliser bag or something.

[citroenxm]

If they are that bad Kevin you may even need callipers Incase the corrosion has eaten the back face of the callipers so badly they may not sit correctly again.. its just a thought. i would also get a rear fitting kit too..

these consist of the pad bolt and nut and the anti rattle spring and also the pad cover.. they are only around a tenner for both sides...

Ive got a couple of THESE KITS in stock. You just never know how badly corroded the bolt can also be

Ive pleanty of calipers in too IF you need any..

[RichardW]

All you need to know about it....Rear caliper bolts

Check the state of the pipes before you start, they can object to being moved about, and may need to be replaced. If you can get the bleed screws and pipes out, then bad corrosion on the calipers is not a problem - just swap them side to side - they are identical, just reverse the position of the bleeds and feeds. Watch out for the small O-ring between the halves if you have them apart.

[Xantidote]

I apply copaslip to the mating surfaces, and not bothered with a gasket. Only had to do the job once in 17 years.

If the corrosion is really serious, then chipping the corrosion off with a small (say 1/2") cold chisel works well. I avoid splitting the 2 halves of the caliper, to avoid creating another problem/job.

[Hell Razor5543]

I know I keep posting this link, but it does work. I have done it on both my previous Xantia and Gracie;

http://www.frenchcarforum.co.uk/forum/v ... =3&t=38467" onclick="window.open(this.href);return false;

However, the feedback on the gasket idea is to make it as thin as possible, so as not to throw the brakes off balance.

You might need rear disks (as shown in CitroJims' photos) as they may be severely corroded.

How are the rear bearings? I would check before you start, as if they are showing their age it could be worth replacing them at the same time (if you have all the right tools), as you would have to take the calipers and disks off. There are links on replacing the rear bearings. The biggest problem is finding a big enough torque wrench to tighten up the center nut.

[Xantidote]

How are the rear bearings? I would check before you start

Good idea - I checked the rear wheel bearings when replacing the discs. On one wheel, bearings sounded as if running dry, and the old grease had gone hard and lumpy. Picked out the old lumps with tiny screwdriver, and squirted new grease in as best I could, using a small plastic syringe purloined from computer cartridge refill kit. High Melting Point grease of course.

[Old-Guy]

....If you can get the bleed screws and pipes out, then bad corrosion on the calipers is not a problem - just swap them side to side - they are identical, just reverse the position of the bleeds and feeds. ......

Oh [expletive deleted]!

I wish I'd known this for certain when I did mine a couple of months ago. I did wonder and then thought "No, that would be too simple; they'll have a conical seat for the bleed valve and a (more or less) square seat for the little rubber seal on the pipe so the callipers will be handed." The advantage would be that (on mine at least) the exposed visible face of the calliper was still perfect. I'd still have painted it (I had a part-used spray can of 'wood-stove' paint, which I know is pretty heat-proof!) but I wouldn't have been left wondering if all those pits are going to fill up with salt! Oh, well sometime when I need something to do...

BTW, I expected the bent bolts to be a nightmare to remove. An overnight soak of all the threads (including pipe gland-nut and bleed-valve) with spray penetrating fluid (3-in-1 brand) and every single one undid sweetly. I fitted the new bolts I'd bought, I'd have been more than a little annoyed if one of the old ones had sheared as I torqued it up.

[red_dwarfers]

Thanks chaps for all the tips, I'll add a caliper kit to the list too. I'll probably leave the job for a couple of weeks.

[Hell Razor5543]

On the two occasions I had to do this the bolts were not bent. I think it is because they are high tensile bolts, more likely to snap than bend. The most important things are preparation (Plus Gas everything daily for a week before you start), and slow, steady application of pressure to undo the bolts. I didn't have any problems in either occasion.