Parking Brake Adjustment

[DerekW]

The parking brake on my 2.0TCT estate does not self adjust and the only way to keep pedal movement within limits is to screw up on the cables - which the manual warns is wrong. Normal method of applying the foot brake doesn't do anything for the parking brake.

Before I get down and dirty, what should I be looking for? ie what fault is likely to cause this lack of self adjustment?

Thanks in advance.

Derek

[dean]

Hi Derek

Must be caliper related surely?!? the pistons should wind in as wear accures and so the pads will never be any further from the disc, sure its not cables stretched, in which case you will have to adjust at the cables, but i think you have to adjust both sides evenly, ie same number off threads showing on the outers of both o and n/s cables...........if not then you've got me.

D

[techmanagain]

Should it come to that, Bendix calipers are available on an exchange basis. Not all suppliers advise you of that, but the old calipers have an exchange value.

[DerekW]

Hi Dean,

The pads seem to be taking up the wear but from the drawing there seems to a series of cupped washers (Belville washers?) which look as if they should allow the parking brake operating rod to slide through and then grip in a new place to take up the slack. Neither Haynes nor the manual give any details.

Hi Techmanagain,

Thanks, that's useful information if the worst comes to the worst - as it probably will!.

Looks as if I should take one of the calipers off for a bench stripdown. I'll post what I find on here for future reference.

Derek

[demag]

Didn't onthecut have a similar problem to this? I'm sure he stripped the caliper and found the handbrake lever (on the caliper) was partially siezed and wouldn't return to the fully home position hence the slack cables.

There are quite a few posts about these things sticking. I think Noz did a pictorial guide somewhere.

[Ken newbold]

I've got my bro in laws car in the drive parked on axle stands with exactly the same fault.

The n/s cable was sticking, so fitted a replacement, still the same, so changed the caliper, still the same.

Checked the other two cables which seem to be free enough but still no joy.

I couldn't actually see anything wrong with the caliper I took off, the piston was free moving enough and the parking brake lever also returned to the off position OK.

Not sure what my next move is. I'm reluctant to send it to the garage as it's likely to come back with a four figure bill.

[robertxmb]

An overhaul kit is available from Citroen for the parking brake mechanism in the caliper.
You could also remove the rubber boot and remove any hardened grease, flush out & work the actuator lever many times with a mole wrench; refill with grease.

Check also that pads are correctly fitted so the one with the "pip" on the back engages with a slot in the piston. The self adjustment will not work otherwise.

The cables are equalised by adjusting at the caliper end so that the pivot lever at the other end is near vertical.

Robert.

[Ken newbold]

Mmm. I did notice that the pads have been incorrectly fitted and the "pip" on the back of the pads is not on the piston side but assumed "it's been alright so far" so I'll give that a try.

Thanks. Ken

[DerekW]

Thanks for all the advice so far. First fine day for some time so I got ordered out to do some hedge cutting. When I've caught up with all the jobs 'er indoors wants doing I'll be able to start on the ones I want to do.

Derek

[dean]

yeah but by the time you've served your time for her you do realise it will start raining again though derek ..........always the way

D

[Ken newbold]

Sorry to add to the off topic but,

why is it women are only interested in cars when they want to go somewhere

[Ken newbold]

Well, finally managed to get it through MOT today, but only just, low effort on n/s parking brake.

I've changed, pads,cable and caliper, but it's still a bit low.

Question,

Is it possible that the plate the the cables fit into, underneath the car maybe bending or cracking?

I just can't think of anything else.

[xmexclusive]

Hi All

Pips on the brake pads fitted the wrong way round or both just in one caliper or nibs on more than two brake pads can all send the parking brake adjuster into trouble. At best you get very unequal pad wear and at worst it can progressively tighten the pads until the heat boils the LHM and you find yourself trying to stop with just the back brakes. Guess how I know. Must have half a dozen sets of recovered calipers now and have not yet found one where the caliper lever is seized. If the pips being wrong have led to unequal pad wear but the worn pads are reused then it is virtually impossible to get anywhere near equal parking brake force on both sides though normal braking does not seem to pull to one side.
On the XM's I have looked at/stripped the parking brake cables are often in poor condition. The lower pair often are worn/squashed/bent where they pass through the metal loops at the bottom of the front struts. The other trouble spot is that all three cables can have worn/misplaced outers where they join at the fulcrum in the exhaust tunnel. This typically leads to loose cables and a very low acting foot brake pedal.

Regards

XMexc

This post has been edited by xmexclusive on July 11, 2008 08:50 pm

[DerekW]

A quick update. Both sets of pads had their protruding nibs in the correct place and were engaged with the slot in their respective pistons. The operating cables look to be in very good condition and move freely. The operating levers move freely and return to the fully off position, but move a long way before they contact the pads. Hence the need to adjust the cables to bring them into contact. So it looks as if whatever mechanism there is inside the caliper to take up the slack is not doing its job.

However the pads are worn very unevenly, with lots of meat on the piston side pad whereas the outer pads are both down to about 4.5mm thickness. I am mindful, therefore, to put it all back together, take up the slack with the cables as before and wait until the pads reach their wear limit. Hopefully new pads will take up all the slack on the parking brake.

For the time being its going to remain a mystery to me. I would very much appreciate a simple description of just how the self adjustment works.

Derek

[DerekW]

Whoops! Double posting.


This post has been edited by DerekW on July 11, 2008 11:19 pm