Parking Brake Adjustment

It sounds very much as if the calipers are not allowing the pads to slide acrsoss into their correct location when the brake is applied. The commonest reasom for this is binding on the small tin packing on the rod on which the calipers slide. Take them out and sling them away and put up with any imperceptible possible squealing on brake application. Rather that than a poor brake.

Hi techmanagain,

Do you mean the pan headed pin that's held in place by a spring clip?

Hope to see you tomorrow.

Derek

The anti rattle spring strip held under pressure by the pan headed pin secured by an R clip offers minimal resistance to movement of the pads in comparison to the forces applied by the hydraulic or cable braking systems, and the same applies to the wear indicating wires sometimes blamed as having a similar effect.

The uneven pad wear is more likely to be caused by one of the following:-
Parking cable drag, Caliper not sliding freely on rod, or Sticky piston.

As you intend to fit new pads; if you have a piston winding tool consider using it several times to work the piston into its bore and operate the hydraulic brake with a well worn set of pads fitted to maximise the travel. The object of the exercise being to free up the piston and ensure it operates easily.

Have a look at Citroen service web site for your car and the overhaul kit for the parking brake for possible further clues.

All the above in MHO. Wishing you good luck and please let us know how you get on.!

Robert.

This will sound a daft question, but what do the locating nibs on the pads look like?

Are they the little 'handles' on the outer edge that you hold the pad by when inserting it into the caliper?

The reason I ask is my S2 failed the MOT this morning on uneven parking brake effort, drivers side much weaker than the other. I haven't yet looked at cable adjustment or anything like that, but this locating nib thing is a new one on me... am I just being incredibly stupid not knowing what they are, I've changed pads 3 or 4 times and never noticed...

Ciarán

Hi Ciarán,

The nibs are on centre back of two pads only. They are raised "pimples"above the surface and are fitted on the piston side of each caliper so that they engage in one of the slots in the piston. The other two pads have plain backs.
Hope thats clear ,you can't miss them.

Robert.

Thanks Robert,

Will whip the pads out tonight for a look.

Cheers

Ciarán

Am I just being really stupid here? I have both pads out and cannot see a difference between them, besides the fact one is obviously marked where the piston has been pushing on it, and the protective backings are peeling off them.

They seem identical in every way, have I missed something?







Have I got two 'non nibbed' pads or something?

Other than this, they seem fine, no uneven wear, and both have plenty left on them...


Any thoughts apprecited!

Ciarán

Have you checked to see what's in the other side

Hi Ciaran

Your pads have no nibs and without this the parking brake auto adjust cannot work.

The pad installation instructions also require the backing strips to be peeled off the back of the pads before fitting.

Regards

John

This post has been edited by xmexclusive on August 12, 2008 09:31 pm

Does this help Ciaran?







I've just done the front brakes on both my cars and on all four sets of pads, the none piston side pad was more worn than the piston side..........




In one case.......considerably more

Hi guys,

Many thanks for those responses. Cheers for the pic minijet, I now know what a nib looks like. The last set of pads I fitted to this car had them, these, as Techman says, do not. I thought I was going mad looking for something which wasn't there, don't know why these pads don't have them.
I forget what brand they are (think I got them from GSF, but will be sure not to get them again next time).

I found the problem anyway, the cable on that side was badly adjusted, with the two bolts together, and not tight against the caliper. I tightened them up and adjusted them, and parking brake performance on that wheel is now a hell of a lot better. I would still like to get the auto adjustment working, so will do so at the next pad change.

Of course, proceedings were slowed by the inevitible cable falling out at the equilizer end, but sure that's always fun, we love it. As if my back wasn't bad enough, removing the wheel was a struggle on its own, it was really fun when I had to lie down and wriggle under the bloody thing...

Many thanks for all the help guys.

Ciarán

PS John, thanks for the info on the backing strip. I wasn't even aware there was such a thing, I am now!

Hi Ciaran

I had a very similar experience with a set of MINTEX pads ie no nibs and a strange thickish plastic layer on the backs (with no peel off paper layer as on some genuine Citroen pads). I assumed the backing was some form of anti-squeal prevention. I didn't have any handbrake problems as I recall but I chucked the pads away when they were less than half worn because the friction material and the steel back were delaminating. Also the backs ended up looking exactly like your photos.

Conclusion - AVOID Mintex branded pads for the XM.

Ken

Hi Ciarán,

Every time I go to my factor for front XM pads we go through the same routine. He produces a set with no nibs and I say they won't do as the auto adjustment will not work. He orders up the proper ones and puts the no nibs back on the shelf until next time when the process is repeated! He has been doing that for years now so seems to be stuck with them.

Re the "fun" of the cables slipping out at the equaliser end there is a simple and effective remedy. slip a cable tie or loop of wire loosely over the inners to retain them in the equaliser forks, and leave it there. You can then work away at the calliper end as much and as often as you like without having to get under the car to reseat the cable ends at the equaliser.

Robert

Ken, I think you're bang on with the Mintex thing, now that I think of it, I think I remember that being the brand name of the pads when I bought them last year... well, never again!

Robert, I must remember to check for nibs next time I buy pads, which isn't very often to be honest. Just out of interest, what factors do you goto for your Citroen stuff, just a generic place?
Its probably miles away from me anyway, but I was just curious as GSF can be helpful at times, and a bit... meh at others

Ciarán

I've just done the front brakes on both my cars and on all four sets of pads, the none piston side pad was more worn than the piston side..........

This will be because the little tin clip on the bottom "pad-retaining slide rod" is binding on the rod. Chuck the tin clip away!