^OPM^

After swapping disks and pads round i think its actually my brake caliper that must be warped so that instead of pushing my brake pads in parallel it causes the outboard one to only touch the outer part of disk-is it possible that the caliper itself mite be warped or bent?

mark

CrisPDuk

It's theoretically possible, but not very probable, the forces required to cause that sort of distortion would do a lot of damage somewhere more noticeable too.
The problem you describe is usually a result of either a sticking piston, or worn/sticking sliding pins (you don't say what type of caliper you have?).

BTW, what do you mean when you say 'swapping discs and pads around'?
Have you taken them from one side and fitted them to the other or have you fitted new

Leslie

Sounds to me as though your inner piston has seized which is why only the outer pad is moving.

You need to exercise the inner piston a few times with something like WD40 squirted on the piston. Use a lever between the disk and the piston to make it move into the caliper and pump it out again with the brake pedal making sure it cannot come right out of the caliper of course. Plenty of WD40 will help. Leave the outer pad in place to avoid a bending force on the disk with the lever.

Les

Les

Spoon

I think your problem lies in using disks. They just aren't up to the job and in some cases can be floppy. You should really use discs instead which are made for the job.

HTH.

Scoobychick

iTrader: (1)

PMSL

^OPM^

I did swap pads but they was only about 2 weeks old and i also swapped discs just to check they wasn't warped and both are ok when on other side-i took brakes apart and could easily by hand move caliper by hand on pins plus i could see piston come in and out visually when brake was applied

^OPM^

forgot to mention car is a mk 2 mondeo so only a piston one side

CrisPDuk

You say you could easily move the caliper by hand on the pins, could you twist it from side to side too?

dpb

Disks on citroen ive got are ****e quality - they starting to corrode also on the inner ventilated edge - dont know whether this is a problem.


sure its not the disks

blockmonke@fsmail.net

I had the same problem on my p reg mondeo, only the conrod decided to pop out and say hello before I could sort it

Spoon

A particularly well known case for being floppy.

Tart Man

Common problem on alot of cars using sliding caliper....

Interestingly the rusty side of the disc is usually the innner side, yet that's the same side as the (only) piston, so not a piston fault, nor sliding mechanism fault - as if it were, it would be the outer side of the disk rusting.

Additionally, the side of the disc that the pads wears the most is the rusty side, so they must be working.


Thus far, once the actual braking system has been ruled out, I have narrowed it down to pad compounds, disc materials and bedding in process. Using original manufacturer's pads does not help - in a number of cases I found genuine pads and discs to be worse that using OEM parts from other suppliers.

Simply put; the pads are too soft, and the disc is too hard. The result is the disk rusts, this then acelarates the wear on the pad; which is too soft to clean off the disk, which in turn ends up acting like sand paper. The result is a disc that has a rusty surface and pads that barely last 10 000miles (if your lucky).

The bedding-in process is a complicated matter but I theorise that the inner disc surface on a single piston sliding caliper is the side that exerts more force. If incorrectly bedded in, the pad can glaze or lose it abrasive properties and the disc may suffer from excess cementite (surface hardening) from the heat generated. The result is a rusty disc on one side, clean the other (teh clean side which is the cooler side that exerts less force).

Proracer

Ive seen warped caliper all the time, mainly due to the brake system got too hot on track. Specially if you using the pad like PFC, they run up to 1200 degree but it can damage the caliper seals and warped the caliper. Most of the race car change there caliper after 2 -3 races.

You need to find a pad that can control the temp, keep it down under 900 degree.

^OPM^

the inner side of brake disc is clean so that works ok-its on the outer face that it only brakes on the outer part of disc-does that make sense?

Leslie

You must have had to work at it to make a Mondeo rod come out B Monk etc.

Different problem of course with a single piston caliper.

Les