Thread: D2a DISC BRAKE QUESTION

did you rotate the disc?
are there wear marks on the inside of the discs?

Maybe your calipers are sticking?

Originally Posted by Pedro_The_Swift

did you rotate the disc?
are there wear marks on the inside of the discs?

The car was up on the jack at the time (one wheel off at a time), and it was in Park with the handbrake on, so I didn't rotate the disc.
Looking at the disc, both surfaces appeared pretty normally shiny, with the only marks that I could see being concentric, parallel to the edge.
Cheers,
Andrew

There is nothing in a disc brake system to move the pads away from the disc, the release of pressure when you take your foot off the brake allows the disc to be in virtual contact with the pad.

The only thing I can think of (thanks Mario) is that the caliper slides are sticking a bit and rebounding the caliper, normally if they are sticking the opposite happens, the inside pads get worn away first because the caliper can not move back from the disc.

Try with wheel off (and safety stand in place) get someone to put pressure on the brake pedal while you observe what is happening at the disc. If when the pressure is released the caliper (piston side) moves away from the disc the only thing causing that would be sticking slides.

Remove the two small bolts (12 or 13 mm head) lift the caliper body away being careful not to extend the fluid line or the ABS wire.

Where the two bolts are bolted in to are the slides, note that there are flats on the end of these, they stop the slide rotating when you do the bolts up again. Ensure that a flat fits up to the side of the caliper to retain it's position.

The two ends should move in and out freely, that is, you should be able to squeeze the flat end towards the disc easily, the rubber sleeve on it may cause it to move back a little but there should be no hardness in them.

How to fix them if they are not free? I have never done it on Land Rover but on other vehicles they will pull out, ensure the rubber dust cover comes off one end and pull the metal sleeve out and clean both it and the tube it runs in. Once clean and freely moving smear some rubber grease over them and reassemble ensuring the dust cover fits back into place properly.

Make sure the pads are properly in place with the anti rattle springs facing up and refit the caliper body.

Sufficient to say brakes are an important part of the vehicle, if you are not competent on the tools don't do it yourself, I have given a brief summary of the job but if you undertake to do it and something goes wrong????????????????????

Give the calipers a liberal spray with some pressure pack Brake Clean. This may free things up and get everything sliding properly again.

Originally Posted by nismine01

There is nothing in a disc brake system to move the pads away from the disc, the release of pressure when you take your foot off the brake allows the disc to be in virtual contact with the pad.

The piston will retract slightly due to seal flex. The pads get "knocked back" by the disc (disc moves due to wheel bearing free play).

Thanks Guys,
Those are the sorts of helpful suggestions I was hoping that someone might be able to give me.
While I'm at it, what thickness of remaining disc-pad material would indicate that renewal is warranted?
Regards,
Andrew

Pads are 13mm new, I usually change them once they get to about 2 or 3mm.
Also need to check disc wear and replace when necessary.