I see lots of people playing with their brakes around here, and I can't help but wonder if I am utterly incompetent, or if there is some sort of trick that I am unaware of. I have posted on this topic before, but with little response, so if you have any ideas, I would really appreciate your feedback.

When replacing worn rear pads with new, or at least thicker, pads; I'm inevitably faced with a piston that doesn't allow the necessary room for the new pads. Therefore, I must compress the piston. I am using the method learned from Ryephile (I think?) by which I insert the points of needlenose pliers into two of the holes on the piston face, and I push hard into the face while rotating the piston clockwise. This does eventually compress the piston, but sometimes I can turn and push all I want and nothing happens. Then suddenly it's like a switch is flipped and the piston retracts into the boot like magic. I've tried opening the cap on the brake fluid reservoir, and I've tried opening the bleeder valves, and nothing really seems to help so much. So there's GOT to be a trick to it, right? How are all the rest of you doing this with such amazing ease all the time?

 

use a "C" clamp to compress the piston.

The how to replace the rotors and pads-
https://www.northamericanmotoring.co...pic=6934&0

 

I've got a "brake tool" that sort of acts like a C-Clamp (but is portable). It's great for the front piston (which, of course, requires no rotation), but it doesn't "grab" the rear face to rotate it. I guess I'll go out and buy a monstrous C-Clamp to get the job done in the future! Thanks for the reminder a la Randy!

 

I really don't know about rear brakes on a MINI but on most German cars the rear pistons must be rotated in to retract them. I wouldn't force them in with a C clamp without a definate answer. The reason for the rear brake pistons needing rotation in has to do with the emergency brake function.

 

Yes. This is the case. They must be rotated while being depressed. I'm guessing that perhaps the C-Clamp head does the job by "grabbing" the face well enough to rotate them with each turn of the handle, while applying pressure. My handy dandy "brake tool" has a "loose" face/contact area, so it is made specifically to NOT rotate while applying pressure, which again, is fine for the front, but not for the rears.

Can multiple brake-fiddlers attest to the efficacy of the C-Clamp method? (Not questioning Randy/God, but just wondering if anyone else has had success with alternate methods! :smile: )

 

(This whole post is excerpted from another thread, but I'm hoping to get more responses before tomorrow morning.)

For the rears I've tried the needle-nose method. That's been the only one that has ever worked for me, but it alwasy takes an amazing amount of muscle and patience to get them to retract. The last time I did it, I pushed and turned for the longest time on both of them, and nothing happened. I then cracked the bleeder screws and that didn't seem to help, but then on about my 10th try (and maybe 100th rotation) they went in like butter. This happened in a similar way on BOTH SIDES. It was really bizarre, and I have no idea what finally "flipped the switch" as it were, to make them decide to retract. I've also had a problem with the rubber boot "sticking" in such a way that it gets all crumpled up when rotating the piston.

I've got to change my brakes tomorrow morning (got an appointment with the dealer on Monday...looking for some warranty rotors), and I'm going to try the C-Clamp method. I still don't understand how that's going to work since the "face" or contact point of the C-Clamp is loose. What's going to make the piston rotate?

Is no one else having any difficulty with this? Is it possible that I'm pushing TOO hard on the piston while rotating? I am supposed to be turning clockwise, right? What's the matter with me???

 

I have a brake tool that I got at Harbor Freight tools that works well on the MINI and my Audi. It turns the piston while pushing it in. It comes with a variety of adapters that fit most cars.
I'm doing mine this morning too. TO bad we can't video conference our garages together!
CALIPER TOOL

 

I've looked into that tool before, and I just didn't want to spend the money. But I might as well, considering how often I'm doing this!

Along similar lines: do you brake swappers find that it's never an easy proposition to get the rears off the rotor? I almost always end up spending 10 minutes or so prying and banging with a screwdriver and a rubber mallet. I even tried (the most recent time) to not use the parking brake for A WEEK, hoping that they would stay nice and loose, but no dice.

Why do I have such a hard time with my brakes?

 

I just did mine on Sat., and had some difficulty. One of the rears came on and off and on no with problem and the wheel spun freely afterward. The other was difficult and I realized the wheel was basically locked into place. So I took it apart and used the C-Clamp method and the wheel spun freely once all together again. The C-Clamp seemed to move the piston just a tiny bit, and it all went back together like new. Double checked everything, drove around the block (I live in the country) did some mild and moderate stops, and put the car back up on stands to triple check. No problems and took it for a longer spin.

Having the brake tool would be the ticket it seems, especially if you are changing them for the track and such.

Brake change 1 hour, Cleaning and waxing wheels from 5k of dust crap, almost 3 hours.

 

As far as removing the rear brakes, it did require a little muscle. I found a large screwdriver between the caliper and down the spine of the rotor between the pads from the top worked wonders. Like shelling a lobster or a shrimp.

I have done number of brakes on different cars, but this style was new to me. Next on to my winter car for rotors and pads (95 Saab) which I am sure will be a real rusted pain in the...

 

Big A$$ C-clamp works peffectly fine. The C-clamp binds up on its own, then twists and pushes the piston in all at once. I used this method for both of my rears (brakes that is) Works great, is really cheap. You do end up turn the whole thing quite a bit, but the second side you do takes 1/2 the time the first side does.


Some of the secret tools I use:
Big A$$ c-clamp
Natural Composite, CNC Milled, Driver's Front Stock Shock/Spring remover
Large Native Georgian Driver's Front Koni/H-sport remover
Wrench' d'impact for the front swaybar, no need for the allen no more

And my ultra secret, Extra Chunky Georgian Speed Wax, in natural Red

Seriously, just use a big A$$ c-clamp.

Ben

 

You can buy a rear caliper tool for just a couple of bucks at most any parts store. It is shaped like a cube with a 1/4 square whole on each side. You plug in a rachet with a short extention and turn it in while pushing down. It is shaped like a cube because each side works on a different type piston. Try to find a small one as the mini has a very small pattern. This is dirt cheap and the proper way to do it. visit any shop and you will find the mechanics using this tool.

 

The standard "cube" doesn't fit the MINI's pattern. I've got one in my toolbox.

 

One side of the cube will work fairly well, except that one point will fit in a hole in the piston and the other will ride along the outside of the piston. This still works but a cube with smaller patterns would be better.

 

the cube is a poor substitute for this tool, the things cost a lot more when you buy from an OEM tool supplier I think the techs out back said their kit ran about $150
The rear brakes have a self-adjustment device, adjusts every time you step on the pedal, this is so that the park brake always grabs.

edit: BTW to those of you who use a c-clamp on the rears, the threads inside the piston adjuster can be extremely sensitive to axial forces, depending on age, and as they get older, they will tend to strip out more easily

 

I hadn't thought about the threading of the thing. Come to think of it, I've had the easiest time with it when I've backed it off a bit (turned counter-clockwise to extend the piston a bit) and then gone back after it. Maybe my threads have just been missing...? Maybe it's threading is as pesky as the oil filter!

 

I changed over to EBC Greenstuff pads a month or so ago on my car, and found that if you use the C-Clamp method, the "foot" end of the clamp will not rotate like you need it to in order to screw the piston back into the caliper. What I ended up doing was tightening up the clamp on the piston until I had a bit of pressure on it (It doesn't have to be a huge amount), then used a small set of channel locks to rotate the "foot" of the clamp, thereby also rotating the piston. Just keep tightening up the clamp to keep some pressure on the foot and piston, and this should work.

Hope this helps.

 

ColoradoMark: It's hard to see the patterns of the attachements on the Harbor Freight set, is there definitely one that fits the four-hole MINI rear piston?

Thanks.