Oh, I've got THAT as well.....

Post by **RichardW** » 07 Apr 2004, 12:58

Fitting the spare on the N/S rear last night in an attempt to cure the vibrations on the Xantia (90% successfully, I might add! – old Tigar has quite a pronounced flat spot on it) I noticed that I am suffering from the corrosion behind the brake calliper problem – so much so that the calliper is touching the disc – oooops…..! (perhaps I should have taken the wheels off to have a look before in the last 28,000 miles I have had the car[:I]!). Anyway – assume I can ‘whip’ the callipers off and clean out the corrosion without removing the brake pipe? Fortunately my mate has got a set of discs and pads in his garage for a Xantia he hasn’t got any more, so should be able to get them cheap[}:)]!

David W · Post by **David W** » 07 Apr 2004, 13:22

Richard,
Nice to be able to tick off all the issues isn't it!
Yes with care it is no problem to lift the caliper away enough to sort the corrosion without disconnecting the pipe.
My way is using a very very coarse and sharp file our blacksmith gave me, its normal use horse hoof shaping!! Most of the corrosion is usually on the caliper and it is quite easy to see when you get back to the proper surface.
I've done loads now and it seems to be an issue on any Xantia prior to 1998.
David

Kowalski · Post by **Kowalski** » 07 Apr 2004, 14:11

The majority of the corrosion on mine was on the suspension arm and I removed it with a scraper made from an inch wide piece of hacksaw blade (off an electric hacksaw) with rubber hose over it for a handle and the end ground to sharp edge (kind of like an improvised prison knife). I greased the contact face between the calipers and the suspension arm to prevent the corrosion re-occuring, I'm not sure whether this was a good idea but it hasn't caused any subsequent problems like calipers falling off etc...
After I removed the corrosion the rear brake squeal I had been having disappeared almost completely, I had greased the backs of the pads and the shims before which made the squeal go temporarily but it came back.

David W · Post by **David W** » 07 Apr 2004, 15:06

Yes it appears a really sharp scraper is always needed. Interesting you had the greatest corrosion stuck to the arm, bit easier to scrape down to steel rather than alloy of the brake. I grease the mating surface as well before fitting.
If you have squealing Xantia rear brakes, and it only goes away for a while after cleaning/copaslip, the fault is mostly misalignment due to this "expanding" corrosion on the caliper/arm face.
David
If you haven't seen it you'd never think such a strong item could be bent so badly by corrosion.
David

Kered · Post by **Kered** » 08 Apr 2004, 17:29

Several years ago I experienced this. As the forum didn't exist then I spoke to Plaeiades where I was given sound advice to the cause and to the greasing of the interface. The chap also said that he's known it to be so bad that it has snapped a caliper retaining bolt!
Drek

mipster · Post by **mipster** » 08 Apr 2004, 20:02

<i>The chap also said that he's known it to be so bad that it has snapped a caliper retaining bolt!</i>
Sounds like mine. It wasn't actually snapped until I tried to remove it though, but it was so weak that it didn't take much force before it went. Cost me a new trailing arm in the end
mipster

blueboy2001 · Post by **blueboy2001** » 08 Apr 2004, 20:24

Be careful when refitting the caliper retaining bolts, I snapped one when I was replacing it and I hadn't done it up particularly tight. Fortuntaley I managed to chisel out the part that was stuck in the threads without damaging them, but otherwise it would have probably meant removing the trailing arm.