I replaced the brake pads all around on my 2006 R50 and after replacing them the drivers side rear brake caliper will not fully disengage.

When I replaced them I also adjusted the parking brake and I believe that I adjusted it too much. When I took it on a test drive the drivers side rear brake got very hot to the point where I was getting smoke but only on the drivers side rear. Probably drove it for 3 miles before stopping and noticing the smoke. I nursed it home and backed off on the parking brake cable. The rear caliper was still not releasing so I figured I fried the caliper so I replaced the caliper. After replacing the caliper it still will not release. I checked the parking brake cable to see if there was any binding and couldn't find any either at the handle or where the parking brake cables split. While it was jacked up I removed the parking brake cable from the caliper reset the caliper back to its fully recessed position, reassembled the brake, and spun the wheel. There was no rubbing or binding so I started the car and hit the brake pedal a few times after which there was significant binding. The wheel would only spin about 1 rotation.

I'm now at a dead end in my troubleshooting procedure and wondering if someone can point me to a next step.

 

The cable moves easy? Did you replace the whole caliper? All i can think of is there is something wrong with the master brake cylinder to that brake line, something in the line?

 

Thanks for the reply.

The cable moves easy for a parking brake cable, from working on other cars it doesn't seem to be excessive. When attaching it the caliper it pulls the spring loaded lever around 5 degrees.

I replaced the entire caliper, bracket and slide pins.

I failed to mention that I thought something like you're thinking in that the master brake cylinder could be creating pressure in the lines and not releasing it. To check this I put the brakes into the rubbing condition and then opened up the bleed valve thinking that if there was built up pressure I would have brake fluid shooting out. Nothing came out during this experiment.

 

The parking cable is cursed and haunted...lol Your MINI wants to e-brake all the time.

I would check that tension and adjustment on the parking cable again. Double check with this thread.

https://www.northamericanmotoring.co...in-an-r53.html

 

the rear pads for a GEN1 have clips that fit into a groove on the end of the caliper piston. If you don't get these clips in the groove the pad will ride on these clips and a new pad is then about 1/16 or more too thick ....

Did you seat the clips properly?




back side of GEN1 rear ... note the clips ... they should grab 3 sides of the piston ... if the piston rides on top of these it can cause a new pad to drag

(ignore the circle - it was the answer to a different question!)

 

That's a very good idea...

 

Thanks for this. I believe I did but those clips don't easily go into the groove. It seems half the time I get the clips seated into the groove by the time I get the caliper with the pad over the rotor the brake pad pops out. It would be nice to have a little step up in that spring so that the edge of the spring can get past the lip of the groove and seat correctly without fuss.

 

I usually slide the pad down into the clip rather than try to snap it in place. Once I slide the pad in, it stays in place if the piston is compressed sufficiently.

 

Going to move you to the Stock Problems/Issues area.

Perhaps dumb, but did you paint the calipers??

 

No, I wish it was that simple. I worked on it some more today taking advice that I learned from this thread. It's still doing it but here is what I did to try and locate it.

1.) Checked visually to make sure the pad clips were in the grove on the caliper piston. They are.
2.) Removed the caliper/pads and left the parking brake cable on. Reset the piston and reassembled.
3.) Rotor turns freely. Turned the car on, pump the brakes and the caliper is stuck again.
4.) While in stuck condition opened the bleeder valve and getting brake fluid movement at what I would expect the rate of gravity. Wasn't streaming out.
5.) Closed the bleeder valve and removed the parking brake cable
6.) Removed the caliper, reset the piston and reassembled without the parking brake cable.
7.) Rotor turns freely. Turned the car on, pump the brakes and the caliper is stuck again.

I can see that that piston extends maybe 1/8 inch after reassembling and pumping the brakes, It just doesn't go back. Strange thing is the brakes seemed to work fine before replacing the pads. I bought the car used and it is the first time I changed the pads on this car but this is not my first time around the pad changing rodeo. Probably 20 brake pad/rotor changes over my life.