How To Check Abs

[simonplatt]

i replaced the discs and pads on my 2004 1.4 c3. i pushed the caliper back on 1 side but on the other side it wouldn't so i released the bleed valve, this of course before i had seen the warnings.

it has since been for an mot and passed, but the brakes now seem to come on sharply when i apply more than moderate pressure, but they do not lock.

i have not tried an emergency stop type test !

otherwise they appear to be as normal.

 

any tests i can do or any ideas please.

[Johndouglas]

Opening the bleed valve is recommended before pushing the pistons back into the callipers so that crap is not forced back into the ABS pump.   If the car has passed the MOT roller brake test, there can't be much wrong with them.

[paul.h]

The brakes on our C3 2003 1.4sx petrol are quite keen, needing very little effort to stop the car, certainly a lot less than our C5 and when swapping between cars takes a bit of getting used to. Probably before you did the work the brakes may not have been cleaned for a few years and seized up a bit, so more effort than normal was required, but you would have got used to it. Now the pads can move freely in the caliper whereas to remove the old ones you probably had to lever them out. The old pads friction surface may also have been glazed.

 

If not already done, you should also clean the rear brakes since these will collect brake dust and the shoes and drum will glaze over. If you replace the rear shoes, note that one is thinner than the other, wrongly leading you to think they have worn badly. Deglaze the friction surfaces on the drums and shoes with such as 180 grit emery paper and clean the drums with brake cleaner. If there is a ridge on the outer edge of the drums scrape/file it off so the drums will go on and remove easier. In the future, if you clean the front brakes do the same, but the pads can be better rubbed on emery paper on a flat surface to deglaze them.

 

When pushing the front pistons in, I have been opening the bleed screw for some time having read the comments as John and also the possibility of reversing the seals on the master cylinder - there may have been a number of cases on Vauxhalls at the time and we had an Astra. These possibilities are noted in the Haynes manual for the C3.

 

If you want to check if the abs is working and the fault light is not on, wait until it is snowy and then at low speed apply the brakes - the pedal will be felt to pulsate.

[simonplatt]

thanks for the replies.