While inspecting my recently-purchased car, my mechanic found surface rust on the rear calipers, which means the pads are not coming into complete contact with the rotors.

Is this a common problem on this model? Will lubrication solve it?

Is it likely the rear calipers are the problem, or perhaps a master or slave brake cylinder? The car drives fine, and the hand brake works as designed.

I've come to the conclusion that, if the calipers require replacement, I'd prefer new OEM to rebuilt. I found TRW/ Lucas Girling calipers on a number of sites, but ECS Tuning indicate a change in application after 1/1999.

Was there a change in the caliper after the end of 1998, or are all B5 rear calipers the same?

Any and all in-sights will be appreciated.

 

Alright back up. Was the surface rust on the *caliper* or the *rotor*? Surface rust on the caliper is common and will have zero effect on your car's ability to stop. Surface rust on the rotor that doesn't go away when you drive is something else. DO NOT lubricate your brake rotors. That would be a terrible idea.

I would do several things before you replace or rebuild your caliper:

1. Check the thickness of your rotor.
2. Check the wear on the pads.
3. Check the boot around the caliper piston. If it looks ok and you can turn the piston back into the caliper, there's no reason to replace it.

If the caliper, pads, and rotor look ok but youre pads still aren't contacting the rotor, take the cap off the fluid reservoir and pump the brakes till they do. You also might need to bleed the system.

 

The rust is on the rotor. 2AM typo.

The pads are new, and one was, according to my mechanic, incorrectly installed. I did not see the pad, and I'm not sure how a pad could even be fitted improperly.

The lubrication I mentioned would be of the "pins" that upon which the caliper opens and closes. I know lubricating a rotor's surface would be foolish . . .

 

lol gotcha. Sorry, i didn't mean to be condescending, but we've seen some pretty ridiculous sh*t on these forums before

Ok so that makes more sense. Installing the pads incorrectly is difficult, but doable. They have little hooks on them that fit into notches on the carrier, and if they aren't installed properly or bedded in properly after installation, you could definitely end up with irregular wear. Other than the rust, what kind of shape are the rotors in? Are both sides rusting or just one? (I mean that two ways, both the left and right sides of your car and the inner and outer surfaces of each rotor)

 

I am unsure about the extent of the rust; yesterday I dropped off a replacement central locking pump ($40 including shipping via eBay) and I saw the surface rust on the outside of the LR rotor. I am going to guess that at least the outsides of both rear rotors exhibit rust. The pads are new and the rotors appear to be within spec.

The reason I bring up the master & slave cylinders is that it seems unlikely both rear calipers would fail in exactly the same manner at the same time.

Years ago I had dragging calipers on the rear of my 100, and after changing calipers I discovered it was a brake master cylinder problem.

 

Makes sense. Do the front brakes work any better than the rears?

 

The car drives fine. The only evidence of a problem is the surface rust on the rotors, which tells me the pads aren't making (sufficient) contact.

 

Someone correct me if I'm wrong, but the front brakes do most of the work, and unless you're doing some hard braking, the rear brake pads don't really contact the rotors as much, which could lead to a little rust on the rotors.

I would assume that if the hand brake is working as it should, the calipers themselves are fine. Try some spirited drive with some harder than normal braking (be safe, not on a main, or much traveled road) and see if can see any changes on your rear rotors.

 

This week so far, we've gotten the turn signals sorted out (carbon on the hazard switch contacts), the central locking (central locking pump), and the ash tray fixed.

Replacement driver's side headlight squirter / piston / cap are en route from Force 5 in New Hampshite, as is a driver's inside door handle from eBay.

Once these matters are sorted, the car can be driven, and the brakes checked out.

My mechanic believes the problem with the rear pad contact might be a proportioning valve, but we'll know more shortly . . .

 

I get considerable more brake dust on my rear then in my front and i have the same pad's all around i have a 2001 1.8T auto


BTW your sig is funny as hell lol and yes it is a wagon and now im gonna call you wagon boy form now on CCA4.