Brakes Wheels 2nd Gen Tires Most liked posts in thread: Help figuring out elusive R53 brake problem

You may have a bad caliper sucking air and or a bad master cylinder.. Would seem to have been found when bleeding by the so called experts though.. 2cents

I see you are in PA, how far are you from Helix in Philly? If it's not to far, I'd call Eric at Helix and take it to them, they'll get it straightened out.

 

^x2

 

Sounds like a master cylinder......and to Helix

 

The rear brake pistons must be fully screwed in when changing pads. If fluid weeps around the bleeder nipple instead of only through bleeder valve when opening, could be a cross thread or galled nipple. As for uneven wear, there could be a kink in the P-brake cable.

 

If your rear caliper is sticking it could be overheating the fluid causing it to boil giving you a mushy pedal and causing inconsistant stopping. I'd take a good look at that rear caliper before I'd replace the master cylinder.

The clues are there if you're paying attention.....

 

:cornut: With all of the above advice................Go to Eric @ Helix in Philly

Jason

 

I agree with maybe the master cylinder leaking. Since the brakes have been bled and it sounds like people have inspected the system for any leaks, I would also guess that you still have air in the brake system, such as in the ABS where it can be hard to get the air out of the ABS. It might take multiple bleedings to get the air out of the ABS block. It would be best to take the car to a shop that can properly cycle the ABS while bleeding the system.

 

Could be a few things, but to me it sounds like the master cyl has an internal leak. I think I'd look into that.

 

If he's going to MINI of Pittsburgh, that's the other end of the state from Helix. I would also try to contact PittStop MINI to see if anyone local can recommend a good alternative to the dealer.

 

For those that are a little geographically challenged Pittsburgh is in the western end of PA and Philly is pretty much as far east as you can go in PA. It's like 300 miles from one to the other. The route is a toll road too, one of the most expensive per mile in the US.

But, If you can get to Helix I'd say go for it.

 

Surely there is at least a good independent BMW shop in your area?

 

Did you rotate the piston as you compressed, on the rear calipers?

 

If you were rotating the piston as you compressed, it shouldn't have been that hard to compress. Was it hard to compress both rears or just one?

 

Tom, since you had the pad completely gone on the inside, chances are you just weren't getting the piston back on the threaded part of the rod so that it would go back in.....I've seen that before. You need to push really hard while you turn just to get it started, once it starts it should go back in easily with the HF tool. Sometimes the tool binds also, then you just need to turn the nut the threaded part goes thru to loosen it up.

The fact that one side was worn completely and one wasn't means either the caliper is sticking and not retracting when you let off the pedal, or the handbrake was left on (was the other side worn the same way? If not, the handbrake was not left on) or the handbrake mechanism is sticking. But again, as it was the inside pad that was worn out, if it was dragging it could have overheated the fluid due to heating the piston, causing the fluid to boil and the pedal to go long and the car to act squirrely....that's what it sounds like to me, given all of your clues.

I doubt there's anything you can do to fix the caliper except replace it - if that's where the trouble is, but based on your description that's what it sounds like to me. Did you clean and lube the slider pins when you replaced the pads?

Same with the master cylinder, only it will probably be more expensive. Check Real OEM for relative prices....

EDIT: According to Real OEM the m/c and caliper are about the same price