rbt

changing out pads, and this is the first time I'm using a 'special tool' rather than the muscle-straining needle nose pliers method to compress the caliper. the tool I got was the universal caliper tool rented from the auto parts shop, not the VAG specific tool. this is sorta like an inverse C-clamp, a reverse-vise if you will. basically a big screw w/ two pressure plates that spread as you turn it. it comes w/ different adaptors to fit the two 'holes' in the caliper.

Anyway, it worked great for compressing the caliper clockwise...but now I can't get it off!!! I'm trying to turn the big screw the other way (CCW), and to do this (because of the 'key' hole) it must also turn the piston CCW. Piston doesn't want to do this. should I try to muscle it CCW, not worrying that the piston will break??

EGainer

i was about to reply to this post with, "do you have the tool," but now i see you have different problem. is there any way you can wiggle it out from behind the caliper? i dont think the piston will spin left, but it might

ModifiedA4

<center><img src="http://pictureposter.audiworld.com/143/brakejob-rearcalipertool.jpg"></center><p>
which disengages the tool.

rbt

OK, new pads are in (did not replace rotors). first slow test drive and there's a *very slight* scraping noise coming from the rears; is this expected w/ brand new pads? I did not notice this the last brake job I did, but those were different pads + new rotors.

Also, what part of the rear brake assembly *retracts* the pads from the rotor when you disengage the brake pedal???? it seems that there is none...once the piston retracts, the pads kinda just "back off" the spinnng rotor by default....am I seeing that correctly????

p.s. I feel really dumb that I did not figure my original question out myself...so simple in retrospect. but thanks anyway!

EGainer

and thats why mine squeak annoyingly even when im not on the brakes.

althought, there should be some metal clips that push that pads back off of the rotor, do you see those?

"The single-piston floating-caliper disc brake is self-centering and self-adjusting. The caliper is able to slide from side to side so it will move to the center each time the brakes are applied. Also, since there is no spring to pull the pads away from the disc, the pads always stay in light contact with the rotor (the rubber piston seal and any wobble in the rotor may actually pull the pads a small distance away from the rotor). This is important because the pistons in the brakes are much larger in diameter than the ones in the master cylinder. If the brake pistons retracted into their cylinders, it might take several applications of the brake pedal to pump enough fluid into the brake cylinder to engage the brake pads."

source - howstuffworks.com

rbt

they would push the pads along the same plane as the rotor face, not perpendicular to it.
the fronts, OTOH, the 'spring' is on the *back* of the pad. weird stuff.

This whole 'floating caliper design' business just doesn't sit well with me! I think I want to upgrade to a BBK even more now.

Ritz

The springs are just there to keep the pads from rattling when they're not engaged