[Mk2] [Turbo] Dead caliper?! Pics attached, would appreciate advice!

[diycinema]

Here's the pics, it's the same on the other side of the car as well:

These are of the inner surface.





As you can see the inner surface looks a bid odd?

The outer surface is fine, nice and smooth and no ridge running on the outside.

I noticed the brake pad looks like a wedge of cheese!

Is it normal to have a ridge on the outside? It chips off so it's level with the disc.

I am guessing because of the uneven wear one of the pistons is sticking but why the ridge?!

[luthor1]

get new discs and pads, ensure the slide on the caliper "slides" ?!!!

Also, check for free movement of the piston. It pumps out and winds in.

Otherwise do the easy thing and just spend £95 a corner and buy recon calipers. They are a doddle to fit and then trouble free rear braking for 20,000 miles at least.

[LuizeGT]

the wedge effect is normally caused by stuck sliders or a knackered piston if fronts but 9 times out of 10 its slider. you can clean it up and regrease to make sure its sliding good, this will last a bit but most of the time the problem returns.

looking at that disk,its been like that for a while so theres a large lip on the disk, needs replacing as do the pads.
as said, make sure your pistons move well, get a G clamp onto them and wind them in, then work the pedal to push them out. if too hard then needs looking at.

if thats rear brakes on the pic then the piston winds in so use a winding tool not a G clamp

[LimeyMk1]

Also check that the pads aren't wedged into the carrier too tightly, giving them a clean up is well worth the effort.

[diycinema]

Great stuff, cheers people

Funny thing is once you prize the rust off there is no lip but for the sake of £30 i'm gonna get new discs!

[Doc]

Your caliper carrier should look like this, you can see the two slider bolts sticking out, they are about 6cm long, and slide in their little tubes that are packed with grease.



If you are very unlucky one or both may be completely stuck in their "holes", i managed to free one of mine (both were seized as car had been sat for a long time) the other i wasnt as lucky (see pics)





The bloody slider snapped off in its hole!
I tried stud extractors and drilling it out, but to no avail, and ended just getting another mount. Lets hope yours isnt the same!

[diycinema]

Arghh not more seized stuff!

I've just spent 2 hours battling with manifold studs which snapped off on the the head!

Ended up welding a nut to the stud a few times which eventually got it off!

Cheers for the pics though, i'll have a closer look next week.

[luthor1]

Use a product called MD40 (not Wd40, "M"). Use this to unseize stuff.

It's extremely powerful, very noxious and for best results spray overnight, and again before you try to move the nuts.

It's saved me *every* time. It basically EATS the rust.

[diycinema]

Sounds like I should have bought some! Where do you get it from?

I found on the head the aluminum sticks in the threads which makes it even worse, only 1 more to go though