My friend and I replaced my rotors and pads this past Saturday. He's done hundreds of brake jobs so we know the work was done properly. (We did NOT think to adjust the "self adjusting" handbrake with the new hardware.)

I noticed (on the way home, of course) that there's a high pitched constant squealing of the brakes... it's almost as if the pads are lightly riding on the rotors... it hit me on the way home from work today that we did not adjust the handbrake. I'm thinking the rear pads may be riding on the rotors slightly... any thoughts?

We installed TSW rotors and Carbotech Bobcat pads as recommended by Dustin at http://www.autocrosscooper.com

TIA

 

This might sound overly obvious, but I'll ask anyway - did you screw the rear caliper piston back into its bore prior to installing the new rear pads?

I don't remember the exact setup our MINIs use, but don't they have a couple of anti-rattle clips, or anti-squeal stickers for the brake pads? Did you install any of these (if there were any to begin with?)

 

a) you DID turn the piston as it was pressed back in to allow for the replacement pads? (you can do a lot of brakes and not see this requirement...but it IS a MINI thing) {btw...this need to turn is connected to the e-brake system}

b) the spring clips on the rear pads are properly seated in the grooves in the piston? (ditto)

 

ditto, the rears can bite back if not done just right. Please check the above info and report back. Thanks Dustin

 

Thanks for the info guys, I'll have to look into this over the weekend. I also noticed that the wear on the rear rotors is not all the way across the rotor surface. On one side it's about 60% and the other rear is about 95% across the surface. The fronts look normal.

 

Dave here's a link to a post about a similar problem. I'm thinking it may be the same issue that you are having. Hope it helps you.

https://www.northamericanmotoring.co...d.php?t=150148

 

Thanks for the link, Crashton (I did a search this morning for squealing brakes but overlooked this one apparently).

The rear piston was indeed rotated and pushed in prior to installing the rear pads. I watched the fluid rise in the master cylinder as it was compressed for each side and we siphoned some out before it could overflow. I know the pads snapped into place in the cylinder channel.

Do you guys think I'll have to take the rear assemblies apart or should it be readily obvious that something is out of whack?

 

Take them apart for the best view and make sure the inside pad clip is clipped to the piston.

 

I could just be pad vibration, I hope you plenty of "brake lube". Mine made a ton of noise until I pulled them back apart and re-lubed them

 

Dustin, do these pads need to be lubed?? And, forgive my naivete... where does the lube go??
My coworker had an idea for me to check this weekend: Jack up the back end of the MINI and rotate the wheels to see if one may be "grabbing" more than the other... also to make sure the pads are seated properly in the slots they rest in. We know they snapped into place in the piston tunnel and the pads were freely moving in their respective slots so maybe it is a lube thing.
One thing I noticed is that going around turns the noise seems to go away... weird.

 

This is the exact same symptom we observed when we had trouble with my friends MINI brakes. We also thought the pads were snapped in correctly as you do. When you check those rear pads you are going to find at least one that is not snapped in correctly.

Look at post #33.
https://www.northamericanmotoring.co...Harbor+Freight

 

Yes, the lube is called disc brake anti squeal or such. It may be by the grease and stuff at the parts store, may need to ask at the counter. It USED to come with pads. It goes over the back of the backing plate. Do NOT get any on the pad itself or rotor of course. And don't feel bad, most people omit this step and they're most of the ones with squealing brakes. For some reason it's often omitted, including in directions. Sort of like a recipe doesn't usually say "season with salt and pepper to taste" at the end. Most of the time if omitted it doesn't matter, depends on the car, pads etc, but if it does you gotta take it all apart again. The experienced shade tree mechanic will always use it to save doing the job twice.

Any remaining grease left after lubing the back of all 4 pads should be spread liberally all over your friends face (who's done hundreds of brake jobs) as a reminder for next time.

 

oops, doubled post for some reason...

 

It's funny I mentioned the lube to him this morning and he said was aware of it but that the pads didn't need it because they are painted (Carbotech Bobcats) and that should eliminate any squeaking.
I'm going on the theory that one or more of the pads may have popped out of the cylinder tunnel. Thanks Crashton...
Now that I think about it, I'll buy some brake lube and slap some in there if I pull them off.
Here's a photo of the front TSW rotor with the red, painted Carbotech Bobcat in place.

 

My rear brakes are making noise because the parking brake cable doesn't release well. On one side, I can squeeze the parking brake thing on the caliper by hand, and the spring pops it back out. On the other side, I squeeze the parking brake thing, and I have to pull it back open by hand - the spring doesn't have enough force to overcome the friction in the cable / parking brake mechanism.

Mine makes more noise when cornering. Well... err... the right caliper makes more noise when turning left and less noise when going straight or turning right. Since the parking brake cable runs along the control arms, suspension movement changes the tension on the cable.

At some point, years ago, there was a service bulletin about bending the caliper end of the parking brake cable housing so it wasn't at such a sever angle. I think.

After 126,000+ miles, it's probably time for me to rebuild the calipers anyway.

But, I haven't checked to make absolutely sure I got all the retaining clips hooked in right on the pads.

 

I looked at my left rear brake set last weekend and I've been misstating myself. The rear pads don't pop into place, they just sit there.
With the pads removed the hub/rotor rotates freely. With the pads in place the hub/rotor takes some effort to move. The pads are definitely hindering the rotation and this is what's causing my squeal.
Jeeze, are the pads too thick?? That may be a stupid thought but thought I'd pose the Q.
I ordered myself a HarborFreight tool so that I can rotate and push in my rear piston should the need arise. On Saturday I did not need to push it it at all after taking the pads out. It was recessed already and everything went back together fine -- albeit with the constantly contacting pads on the rotor. Ugh.

 

Okay, I just got off the phone with Dustin at AutoXcooper.com and he told me the rear inside pads have a CLIP on them that is supposed to snap around the edge of the piston head. Makes sense now of course: if the pads can't retract with the piston as it pulls back, how are the pads going to stay off the rotor face... now let's hope I can get the pads snapped into position on the piston face.
Thanks for the heads up, Dustin. Wish me luck.

And the capper, from Wikipedia...

1. Remove the pads - Note how each brake pad is attached. They typically snap or clip in with attached metal clips. Remove both pads. They may take a little force to pop out, so take care not to damage the caliper or brake line while getting them out.
2. Put the new pads on - Spread the special lubricant that came with your pads, (if it's not provided you can get it at any auto store,) on the metal parts on back of pad and the everywhere it comes in contact with the caliper. This will prevent a lot of annoying squeaking. Attach the new pads exactly the way the old ones were attached.

 

Look at post #33.

https://www.northamericanmotoring.co...d.php?t=150148

Look at the pictures & you will see what AX Cooper is talking about.

 

"As I said, the shop found that indeed, the rear inside pads had not been installed properly. They needed to be clipped onto the piston with those three metal wires on the back of each pad."

CRASHTON!!: "I love you, Man!" comes to mind. THANK you! That is THE link I needed.
Now my LAST question on this subject:
When I take apart the rears... do I need to compress the caliper piston in or do you think can I just snap the inside pads onto the piston and then quickly reassemble? If I need to compress the piston, I'll have to wait for my HarborFreight tool to arrive - enroute but a few days away - unless their shipping is faster than 7 - 10 days as they indicated. If not, I could do this job in about an hour for both sides.

 

A week ago

"b) the spring clips on the rear pads are properly seated in the grooves in the piston?"



Actually, you shouldn't need to compress. Now it would seem the piston is riding ON the clip making the pad too tight. Once the clip is properly positioned into the slot the result will be a 'thinner pad' allowing the clrnce you need. BUT there is a possibility that the time spent with the piston hitting the clip may have damaged it.....

 

I agree with what capt said. You should have enough clearance once the pads are snapped in correctly. I be surprised if they were damaged in any way. Go for it.....

 

Capt, I guess I needed the visual to understand the "spring clips." Now I get it... thanks for testing my brain anyway. :-)

I'll do the job after work or tomorrow morning.

When I looked at the piston face last weekend it wasn't damaged at all. I'll hope for the best this time... and apply anti squeak grease to the metal on metal areas (but not the rotor or pad face - that much I get, lol).

 

Case closed and lesson learned!!
I attached the inboard pads the way they should be and now I'm motoring with silent, strong brakes. Took me 45 minutes including setup and cleanup time.
Many thanks to all of you who assisted.

 

Thanks for the update Dave, good to hear all is well.

 

Lol, the saga continues... yesterday I pulled into my parking and heard squealing... going forward and backing up. My guess is maybe the front pads are the issue now that I corrected the rear pads rubbing on the rotor.
I'll lube up what I can on the fronts and hopefully find a pad that's unseated from the piston channel.