Newbie DIY mechanic here. My R53 had the misfortune of being left outside a garage for the salty months of spring as it was set to be repaired just before COVID closed all garages down. I felt like the brakes were very front-biased since then and the car was definitely screechier than usual while in movement although the pads had lots of meat on them (I'm assuming I had drag). I was greeted with a seized, rusted mess in the brake area as I checked things out and was set to change the pads. Everything was very stuck as I tried to push/rotate the caliper piston in. I'll mention that the brake fluid has 8 months / 2k miles on it.

After a bit of research, I opted to use the hydraulic system to induce some movement in there. It did work, but I'm having the hardest time putting the pistons back in. They do rotate, but with quite a bit of resistance and without making any headway inside the bore. The retaining clip is frozen inside the mounting holes due to rust and I have had to bend it.

Given the condition of the calipers (see below) and my usage (weekend driving and occasional track), what should my course of action be? Get the appropriate tool to push the pistons in? Get new ones altogether? Thanks, NAM!




(hopefully this is in the right forum - apologies otherwise)

 

in hindsight it would have been a good idea to have someone familiar with this job help you first time out ... did you have a MINI specific reference to guide you, like a DIY from here or the Haynes Manual?

I think your basic problem is lack of familiarity with how it should work. I'm very surprised you could not get the spring clip off and pretty sure you've trashed the one I see ..... IME it doesn't make enuf contact in the holes to establish a 'freeze' .. ya just need to know where to pry . . . it is under tension

The rear piston needs both the turning motion and the press motion at the same time to retract properly. Sounds like you expect it to 'screw' back in and this is not the case. even with the 'tool' it often takes a few times to get the feel for the right amount of press plus turn required ... it also is a good idea to release the pressure in the fluid system to easy the push back. This can be accomplished by loosening the reservoir cap or opening the bleeder at the caliper (each has its fans) <if you loosen the cap be aware that you will push some fluid back to the res' so the level will rise .... watch for overflow.> Since the piston DOES turn it does not appear to be frozen ....

I've shown many a first timer how to do this job in my garage .....

 

Thanks. Truth be told I'm a complete ******* as a mechanic, but am afraid I don't have any friends that would be more experienced. I was looking to inspect/change pads following Pelican + Mod MINI's instructions and backed myself in a corner after I deformed the spring clips which unseated the old pads. When the piston seemed completely frozen a quick search recommended pressing the pedal. The brake fluid reservoir is open, but I haven't tried the bleeder screws.

That being said, the spring clips in the front were very easy to get off, and I still haven't been able to remove the old ones with any combination of products and tools. They do seem to be frozen in there. I will put more time in it with more patience and trials with an eye on finding the force/rotation feel (I am using one of those cube ratchet attachments) - and is there anything else I should do? TBH, telling me that I'm not cut for this and that I should get it towed / get new calipers altogether is a valid answer.

 

are you familiar with 'pb blaster' good for unfreezing bolts and the like (don't get on the pads tho) https://blastercorp.com/product/pb-blaster-penetrant/

you're trying the $10 cube thing? The 'proper' tool is about $45 - $50 from various sources. I got mine from Harbor Freight years ago .... https://www.harborfreight.com/automotive/auto-maintenance-repair/brakes/disc-brake-pad-and-caliper-service-tool-kit-11-pc-63264.html
p.s. some major autopart chains will LOAN a similar tool (leave a deposit)

profile says you are in CA ..... true? Have you sought out a local MINI owner group?

the e-brake is OFF while doing this I hope ..... did you check the caliper to see if the e-brake cable is moving when you move the handle . . .

 

I've heard great things about PB but don't have it handy. I went for Fluid Film / WD40, which may both be inappropriate here. I'll try it out.

People said you could get away without the tool and just use needle-noses and pressure but that's probably before pushing the piston out like I did... I'll get the tool off the web. CA as in Canada (Québec) in this case, so not a ton of MINI activity unless I'm missing social media groups.

And yes, e-brake off - but I haven't done that test, I'll report on that.

Thanks again!

 

You're not "not cut out for this," and don't let anyone tell you different. If anyone tries to imply they didn't make mistakes while learning to wrench, they are either lying or haven't done anything, or both.

Throw the cube in the trash, and go buy a good tool. You can get away with the cube, or even the needle nose trick, on a clean, well serviced caliper, which you don't have.

A lesson that's never learned too early (but often learned too late): the right tool makes a novice mechanic look much more skilled, and makes challenging jobs bearable.

You mentioned track duty. I'm not an expert on these brakes, and haven't torn mine down yet (hopefully this weekend when the rest of my parts come in) but I've serviced similar setups quite a bit on Mustangs. I would not put that caliper back on a car without first tearing it down and rebuilding it. If your time is more precious than your money, you might be better off just replacing the caliper(s), although you will miss out on the learning experience. I'd also throw on some stainless lines since you'll have to bleed the system anyway.

Have fun. Even the best pros have wrench-throwing moments. 😁

Oh, and PB Blaster is a different animal than WD40. Buy a can. You're going to need it.

 

I had a little trouble with one of the pistons on my rear calipers and I used a c clamp to put a little more pressure on it then turned it some more. It moved enough to slide over the pads.
Imho, if you're interested in tracking the car remove and replace all the calipers and put Goodman's brake lines on it.

 

A lesson that's never learned too early (but often learned too late): the right tool makes a novice mechanic look much more skilled, and makes challenging jobs bearable.


I agree kinda sorta ..... I'd say that if you are wanting to be a wrench turner .... it is a good idea to buy decent tools. And don't be afraid to buy a 'special tool' if it will get the job done (probably still less cost than a mechanic <who HAS this tool>)

 

Following up on Husky44's post, if you opt for new calipers, tear the old ones down just for the learning experience.

 

We already know he's good at tearing down... 🤣



Actually this is a really good idea. I'm just a smart-***. 😁

 

Smart-assery is always appropriate.

Maybe we we need a mistakes-I've-made thread in General Mini Talk. I know I could contribute.

 

Not sure I should contribute. There's only so much space on the internet... 😲

One of the forums I belong to for another car model has a "Doofus of the Month" award. It's actually a high honor. Maybe we could start something similar?

 

... whoops .

I've opted to do exactly that - get the new ones, figure the old ones out. This comes at the wrong time given that it's my daily/vacation drive and because a lack of confidence in making it work well and safely in short order. I hear ya, Husky44, and I don't intend on giving up but I'm better served with the shortcut here.

My wrenching experiences have been pretty humbling up to now (first car). This car is giving me plenty of opportunities to build the skills up so I should be up to speed soon enough .

 

Sounds like a good approach, and a good attitude.

Changing calipers means you will be opening up brake lines which means more opportunities to learn.

First, buy a set of flare nut wrenches. Do not attempt to remove brake lines with a standard open end wrench. You will ruin the flare nut.

If you have the time and money, replace the rubber hoses with stainless steel, particularly if you are fairly certain about tracking the car. If that's down the road a year or two, and budget or schedule is tight, then they can wait, assuming your rubber lines are in good shape.

Brake fluid is bad for paint. Be careful to keep it away from finishes, have lots of rags, and clean up asap.

Whatch several good videos on brake bleeding. It's a source of great frustration. Consider buying a pressure bleeder or Mighty Vac. But this is one task that you can do the old fashioned way, with a helper and patience.

Have fun.

 

Thanks again. I'm going to get the stainless lines on all four. I actually already have the Motive power bleeder and have done the fluid change at the beginning of the year, and I guess that was one example of the proper tool making the job easy as it was very smooth and satisfying. I'll get the flare nut wrench and some courage for the weekend.

I am tracking the MINI to the tune of a few times a year already! What an insultingly quick car on tight circuits. With the new pads (EBC Yellowstuff), calipers and lines, hopefully the brakes will have a bit more stamina as the fade gets real quick.

 

Alright, got the calipers yesterday, PB'd everything overnight. Wish the prep would've gotten me past step 1 today . I cannot for the life of me get the emergency cable off the old assembly. Any tips here?



Edit: reply #3 here doesn't sound great for me, as does this... yeeesh.

 

Hope you got your e brake cables out. I got lucky. Mine just popped out.

Be glad you bought new calipers. Rebuild kits don't seem to exist. I had one torn boot. Got my calipers painted and supposedly have a new boot being delivered tomorrow by Amazon.... Or sometime between Monday and Wednesday. 😜 They don't seem to know for sure.

 

Happy the job went smoothly for you! Our R53 are similar-ish as far as the Valeo clutch, pulley and camber plates go.

I'm sad to say that the tool rental shop recommended going at it with heat and that even piping red and deadblows aren't getting the thing out on either side. The Mini will get towed tomorrow and I'd be hella surprised if it didn't come with a e-brake replacement on top of everything else at this point. Not sure if the e-brake could have or should have been saved. Quite disheartened by the results, especially as it's going to cost more than if I just drove it there in the first place.

 

That stinks. But it happens.

If you're replacing your calipers, couldn't you just cut the cables, and replace them? Wouldn't require a tow.

Looks pretty simple from the Bentley manual.

Hope you have found a good independent shop to work with. I'd avoid dealership service departments, especially for a task like this.

 

Took my sweet time here to reply, but here goes. Found no one willing to finish the job, so I went about it myself. I think I was hoping to save myself the trouble and to find someone who wouldn't have to sacrifice the parking brake. The rest went okay enough, and the car definitely braked and accelerated much better outside of the handbrake pulls to nowhere.

Unfortunately, I had gotten Koni FSD shocks that (similarly) no garage was willing to install so I got a single joyride out of the MINI given that my very own strut replacement job feels unsafe (random noises) . See ya in another thread...