Brake binding

Xantiargh · Post by **Xantiargh** » 04 Mar 2003, 22:19

Investigating poor mpg. Jacked up rear of car, if I spin rear wheel it rotates 3/4 of a turn and can hear pads rubbing.
Is this cos I've only jacked up one side, or does it mean brakes are binding?
If it is that the brakes are binding, is it a case of removing pads, lubricating caliper, pushing it back and reinstalling pads; or is something else amiss?
Cheers
Mike

Homer · Post by **Homer** » 04 Mar 2003, 23:35

That doesn't sound like they are binding badly. Disk brakes always rub a little because there is nothing to phsically push the pads away from the disk (unlike drum brakes).
Try removing the pads and pushing the pistons back a little see if that improves things. If one is stuck then you should notice it.
Keep one pad in place while you push the other piston in otherwise the back pressure can pop them right out[:0]

NiSk · Post by **NiSk** » 04 Mar 2003, 23:40

If you have trouble rotating the rear wheel(s) then you've got binding rear calipers. Unfortunately this problem occurs on nearly all cars fitted with disc rear brakes. Most people drive carefully and under these conditions, the rear brakes are hardly ever used. This results in them binding on the rare occasion when really need them - and they stay jammed on (partially). The repair is as you suggested, down to dismantling, lubricating and reassembling. And although it sounds drastic, the only way to prevent it is to drive like maniac and really use the full braking effect, or make sure you perform a couple of emergency stops every month (hopefully not when I'm behind you).
//NiSk

jeremy · Post by **jeremy** » 05 Mar 2003, 01:01

As has been said disc brakes always seem to drag a little but obviously the question is the drag so severe that it is affecting fuel consumption etc.
The simple measure is what is the temperature of the rear wheels. If after a couple of miles without the brakes being applied the rear wheels are cold then you haven't much to worry about. If they are reaaly hot then you've got a problem.
Another indication would be the general free running of the car - does it roll if you release the brakes without the handbrake being applied and does it tend to drop at the back WHEN you move off. This would bea similar effect to moving off in a conventional car with trailing arm suspension with the handbrake partially applied.
Just a n observation - I've seen very few if any postings concerning rear brake problems on Xantia on here.
Jeremy

arry_b · Post by **arry_b** » 05 Mar 2003, 03:43

You could also check to see if one of the disks is heat discoloured from dragging and overheating. I had one turn blue on a Vauxhall once because of that. Made it obvious which brake was having the problem.

maxrobertson · Post by **maxrobertson** » 15 Apr 2003, 21:35

If it's a scraping noise, see my posting on page 2, REAR BRAKES - FOX.