citroen c5 front brake imbalance

[garyfitz123]

Had my 2003 citroen c5 up for MOT...failed due to drivers side handbrake not pulling....mechanism was seized up completely. I got it freed up with a bit of WD40 and moving it back and forward. Anyway....when trying to loosen it up the piston shot out. Eventually got it screwed back in (took me ages to realise it was a laft hand thread.) Bled the brakes by loosening the bleeder screw and pumping the brakes.

Anyway....took the car for a re-test and failed again for service brake imbalance...45% imbalance with the weaker side being the drivers side. The handbrake is also alot weaker on the drivers side.

Brake pads seem fine, and the discs are perfect.

Any ideas as to how to fix the imbalance?

[markflip]

Could need a rebleed (vacuum method is the best if you know someone with the kit) but it is usually OK bleeding the 'old fashioned way'

The other likely candidate is a seized/sticking sliding caliper - Check the sliding caliper guides and make sure the channels where the pad backings sit (and slide along) are clean, they are prone to developing a 'notch' of corrosion/dirt buildup that stops the sliding component moving smoothly.

You sound like you know what you're doing, so I'm assuming the pads/discs didn't get contaminated with wd40 or hydraulic oil during the repairs and bleeding?

[garyfitz123]

I took out the two guides...cleaned and re-greased them (normal routine for me anytime im working on brakes). Will check tomorrow the area where the actual pads sit and slide...i did give them a small coat of copper grease, but maybe the area on the caliper needs a good cleaning.

I was careful not to contaminate the pads....although I know that one of the pads did get a shot of brake fluid when I was bleeding them...but got it dried off straight away...and i gave the pads a run with some rough sandpaper to take the glaze off them.

If they still needed braking would I not have a spongy pedal? or could i have a good pedal and still some air issues?

Whats annoying is that the service brakes where perfect before i touched the handbrake...only 2 or 3 percent of an imbalance IIRC.

[citronut]

maybe the piston did not locate its self into the adjuster mechanism properly on re/fitting it,

or as Mark says air in the system still

here is a one man easy kit bleed these are very good and conect to your spare wheel i think the MAX pressure is around 18 to 20 psi,

http://www.carparts-direct.co.uk/home/brake-bleed-kit" onclick="window.open(this.href);return false;

a local factors/Hal frauds might stock these


regards malcolm

[garyfitz123]

Just bled the brakes again....defintly no air in the system. gave the calipers a wee knock with a hammer so that any air bubbled would rise to the top and fluid ran clear.

maybe the piston did not locate its self into the adjuster mechanism properly on re/fitting it

I did spend a considerable amount of time getting the piston to rethread (took me a while to realise its a left hand thread doh!). Don't have a rewind tool, so I had a G-clamp in the piston and then using a pair of water pump grips to wind the piston. I was very careful not to damage the rubber. I think it located properly.

I'm lost at this point myself

[garyfitz123]

Just an update on the above thread.....long time ago. It turned out that I hadn't the caliper located onto the wee spud on the brake pad. Flew through the next MOT no problem.

[Jeff]

Angle grinded off the pin facing the piston last time I had brakes apart.

Is the pin really necessary? Its not as if the piston and pads can go any where is it?

[citronut]

the pin is there to stop the piston rotating as the internal mechanism adjusts it self up with pad wear,

if the internal mechanism rotates the main outter piston when trying to adjust it wont/cant adjust up,

the trick is to make sure the piston is set at the correct point to line a slot up so it clears the pin fully as you swing the caliper back down,


on BX's there is a groove next to just two opposite slots, and you have to line one or the other of these two slots up for the pin to locate into