I need some with my first Mini brake job.


I read a Mini how to brake tutorial and thought I'd give it shot changing my 2007 (R56) Mini Cooper's front brake pads. After I have changed the pads on my BMW E38 as well my old Dodge Stratus too. I would never ever consider myself an expert or call my self a mechanic. Newbie all the way!

So here is the problem. I changed the front brake pads and brake wear sensor. At no time did I ever open any bleed lines. I did remove the cap from the master cylinder. After the pads were replaced I put the cap back onto the master cylinder and started the Mini. I expected the pedal to be soft at first and go to the floor,and it did. However, it will not return to firm. I have pumped and pumped yet it still slowly travels to the floor. Please advise!!! Thank you in advance.

 

Has the brake fluid ever been replaced.... From your manual:

But really, with today's computerized cars (20 some computers on board!) and the safety systems controlled by such ABS + CBC + EBD ....... I do not plan to ever work on the MINI beyond checking fluid levels and tire pressure. Niot to mention the 1st 3 years maintenance is FREE bonnet to boot anyway.......

This may just be the 1st vehicle that I don't change the oil myself.......

 

Well My Mini is a 2007 and is well out of the free maintenance period. I plan to have the fluid changed next week.

 

Having these systems doesn't mean that changing fluid is any different or any more difficult.

 

Bleed it. Start from rear passenger, rear driver side, front passenger, and last on the driver side. It's most likely that air went in.

 

Did you compress the piston in the caliper in too far when you replaced the pads? Sometimes, if you overdid it, it could get stuck. Take the caliper off again and make sure that you can see that the pad shows contact with the piston. If you don't see any evidence of contact between the piston and the pad, you can turn the piston a few times by hand to get it to move out enough to reach the pad.

 

I am pretty sure the pistons have contact but I will double check tomorrow.

@Ed955S I am thinking along these lines too. Perhaps air got in somehow. If that is the case I think I better go on the side of caution and have a professional have a look.

 

Get a vacuum-operated bleeder kit (I believe you can "rent" them at Autozone for free) and bleed each line, in the order listed above.

You can get brake fluid with colored dye in it so that you know when the new fluid has filled the system. have someone stand by the master cylinder and fill it as the level drops. Make sure it is someone you trust, as brake fluid is nasty, nasty stuff on paint and finishes!

You've come this far, go ahead and finish the job! If it doesn't work after all that, call a professional!

 

Some things are best left to the professionals....... They check rotors for wear, turn them or replace them. Have all the correct tools and experience.

Brakes especially - your life could depend on them!

 

My experience has almost been the exact opposite it sounds like. Many years ago I used to do a lot of my own maintenance and repair work on my vehicles. But as they became more complicated and advanced, I started relying on shops to take care of everything.

Since having my MINI and access to all the community resources, I'm finding myself doing more and more work on my own.

 

Thanks for the good advice all. The dealer is not always the best mechanic. I took the Mini in for an oil sensor and new catalytic converter recently. Had to go back twice! Doing this brake service I noticed that there is some sort of a plug that was left dangling just under the place where it should be plugged into. I cant describe it because I do not know what it is yet. Also the air intake piping is loose. A bunch twenty-something recent mechanic school graduates are not always the best choice. Thats what it seems you get at BMW dealerships. BMW wants to charge me over $500.00 just to change the oil pan gasket on my old 7 series!

 

All BMWs and MINIs are designed to have the rotors replaced with the pads. Dealers won't turn rotors.

 

Use something like ATE Superblue fluid. That way you'll clear;y see the difference when the new fluid is in the system and the old is flushed out.

 

If you used stock pads, made sure everything is installed correctly and the guide bolts are tightened to spec, I can't understand how the pedal could be soft and go to the floor unless as jdmef8 said with regards to compressing the pistons "if you overdid it, it could get stuck." Really the pad replacement isn't that error prone and even if the rotor was too thin, it would not cause the feeling you describe.

 

No, I checked it again today pulled all apart and put it back together. Pistons are grabbing correctly. Pedal is hard (normal) engine off. The Mini even stops when the brakes are applied. The pedal just slowly goes to the floor. It come back up when released. Going to try and bleed them tomorrow.

 

Question if the piston is or was stuck, how would I un-stick it?