WRXdisc brake's uneven wear.

[Johnno1951]

Hi Scooby owner's, Can any-one tell me why the discs on my scooby have badly worn on the inside face's. The pads have only been in contact with half the disc.The other half is badly corroded,i have the car serviced every year.Do about 5,000 miles between each service,if they serviced the brakes properly they would not be in this state. Not a happy bunny with Subaru Service Centre's.
Now replaced all round with a Tarox brake's set-up.

[74merc]

At a guess, I would say that the slider pins are rusty and are preventing the pad from moving freely within the caliper. I've got 4 pots on my Outback and that is what happened to them.

[ohtari]

Newage 4 pots? Seized pistons, very common. Mine has done it again even though I replaced the pistons for stainless.

Brembos, the answer is Brembos

[Johnno1951]

Will be watching for problems, if the same thing happens again.I will be changing the calipers. So what's the best type of calipers to fit on a 2003 WRX.

[Konan]

Fighting the pistons on WRX 4 pots appears to happen to me on a 6 to 12 month basis. I'm on stainless pistons, so they are always fine but the lips on the calliper itself get grotty really quickly. Last time I rebuilt them I used more red rubber grease than I usually would in the hope it'd discourage moisture (also found I had a tiny nick in the piston seal.

However, when they stick on I usually find the result is that the pad wears into a wedge shape (as well as one wheel getting dusty rather quickly), rather than any of the disc surface being missed.

What I have observed is, when a piston sticks because the pad then isn't being pressed in parallel, it rotates a bit in the calliper and bends the retaining pins out of shape. Combine this with general crud and corrosion and it might mean the top half of your pad isn't free to move. On two occasions, I've had to use a hacksaw blade to cut the pin in half before I can get it out with a punch!

I hate the bloody things!

I'd switch to Brembo (which aren't immune to sticky pistons either), if it wasn't for the fact I'd have to change both sets of wheels to clear them. Not a lot of rims have spokes to suit so you need sti wheels or something like rota GRAs.

Last time mine jammed, it was so stuck that I had to run the engine as I needed the servo to help me pop it!

Edited by Konan on Sunday 15th November 12:01

[nw942]

My Subaru dealer would always 'refresh' the brakes when I took it for a service.

Didn't think that it was part of the official service routine, but taking the pins and pads out every year and cleaning things up is worth doing.

[Mr Taxpayer]

As well as every thing said before, 5,000 miles isn't much in a year and the rears probably won't be getting used. The front bias means you have to do some pretty heavy braking for the rears to really work.

[ohtari]

Mr Taxpayer said:

As well as every thing said before, 5,000 miles isn't much in a year and the rears probably won't be getting used. The front bias means you have to do some pretty heavy braking for the rears to really work.

???

4 pots front, 2 pots rear...

[Mr Taxpayer]

ohtari said:

Mr Taxpayer said:

As well as every thing said before, 5,000 miles isn't much in a year and the rears probably won't be getting used. The front bias means you have to do some pretty heavy braking for the rears to really work.

???

4 pots front, 2 pots rear...

It's a common trait on performance vehicles that don't use the performance enough. Pop over to the Porsche forum and look at how many 'one lady owner' Boxsters suffer similar problems. We also have it with HGV with tag axles that aren't as loaded as the rest of the vehicle.