Rear Left Brake Caliper Touching

[silasthesailor]

Hi all,

 

My rear left brake caliper was found to touch the rim and make a grinding noise under moderate braking. The garage swapped wheels but the problem was not solved, he was puzzled and his solution was to grind down the caliper a bit.

Has this happened to anyone ? Could it be a serious safety problem?

 

Thanks 

 

Silas

[Johndouglas]

It's a well known problem with rear callipers on C5 - also on the previous Xantias and BXs. Due to the two different metals meeting together, you get a build up of corrosion within the joint. The corrosion is sufficient to push the calliper so that it begins to rub on the inside of the wheel rim. What is required is to remove the callipers and scrape away the hard deposits. Citroen DIY mechanics, having done the job, coat the two surfaces well with copper grease; others even make a gasket from plastic sheet. Both methods delay the build up of future corrosion. The only difficulty one may find in doing the job is the removal of the two calliper bolts on each calliper.

[silasthesailor]

Thank you JohnDouglas, much obliged. 

[paul.h]

On one of the C5 sections there is a pinned topic on cleaning the rear brakes including the calipers. You can do it without disconnecting the brake pipe so do not need to bleed the brakes afterwards. If you look closely you may also find the inner brake pad has worn more than the outer one and could need replacing. http://www.citroen-owners-club.co.uk/citroen/topic/6881-removal-of-rear-brake-calipers-pad-replacement-c5-to-2008/

 

I would not bother using that garage again, they do not know about the C5 and have not investigated the problem enough to find out what was wrong or even checked on the internet for a problem that affects all C5s and earlier Citroens. On the C5 Technical section there is a pinned topic of common problems.

[ESL57]

 Grinding the caliper down is the bodge of all bodges. Mine had that done when I got it last year.

   My bolt heads had been ground as well. No chance of a socket on them. I had to weld massive nuts on to what was left and get them out that way.

   3 bolts came off and 4th snapped well inside caliper. Got it out eventually and what a pig it was! 

      2 new calipers from Ebay at £90 set (good price) pads and discs.

   It is better done as the car is a liability until that lot have been renewed and proper remedial work completed.

[FridgemagnetC5]

 

 

Has this happened to anyone ? Could it be a serious safety problem?

 

Yes, and yes. I went to replace the rear discs and pads in a 2001 C5 a few years back and noticed that the new discs were jamming in the calliper. Initially I thought I had bought the wrong discs, but no, it was galvanic/electrolytic corrosion pushing the calipers out of alignment. IIRC the rear callipers are formed of two alloy assemblies that part when the fixing bolts are removed, so be prepared for brake fluid spills. Also the Haynes manual says to use new bolts on reassembly, so there's that to consider.

 

With my callipers in their corroded state I did notice a very variable performance in braking. The brakes were OK most of the time, but every now and then (generally after going through a big puddle) the brakes would be very weak. These issues went away once the calliper corrosion was removed and everything was back in alignment again.

[paul.h]

The pad cover fixing bolt should be tightened back up after removing the cover so that the 2 halves of the caliper do not split when the caliper bolts are removed.