Parking brake - again - stuck caliper

[rns-e]

So like many others, I have had issues with the parking brakes. I've taken them apart, cleaned them and greased gear and everything and new pins.

Everything seemed to be ok, but then out of the blue, the left got stuck again. I took the wheel off, took the motor and gear off and went to turn the caliper back to release the brake. But it is stuck, as in completely stuck.

Any ideas how I can get it loose so I can move the car and get it home?

 

[tmyl21]

Just reading this post

So what was the outcome!?

Most recently when the parking brakes stuck real tight on my MS the driver's side parking brake pad was pulled off clean and I found it the next day in the street at my driveway entrance.

 

[rns-e]

Have not had time to go look at it again and it is lousy weather. I'll go by again today and see if I can get it loose. It's the piston that is stuck and I have to find some way to rewind it

 

[tmyl21]

Have you not been able to move the car in a week?

And if that's the case where is it disabled?

 

[rns-e]

It's been sitting for 5 days now. I haven't had the time to go and try again. It's about a mile from my house, so not that bad, just inconvenient. Have other cars so we are mobile. Didn't want to call a tow truck as it has to be a fixable issue. It's a mechanical issue, I just don't understand how the piston can get stuck like that. when I cleaned and greesed the caliper I also made sure that the piston was completly smooth and clean.

 

[Russell]

What year is your car? Does it have the separate ebrake caliper?

 

[rns-e]

05/2015 P85D with separate ebrake caliper

 

[tmyl21]

I'm 8/2013 build with a 17xxx vin, also with separate ebrake caliper. I'm parking smoothly with no issues with one ebrake pad missing lol

 

[rns-e]

After trying every single tool we could think of turning the piston back and having no luck, we turned to brute force and took out the Club Hammer and hammered the caliper off. It was not for the faint-hearted, but it came off and the car is driving again. There is something wrong with the pin driving the piston. I'm properly going to get a new caliper, but I will be taking the old apart and see what coursed the failure.

 

[tmyl21]

Nice! At least you got it to move and to further diagnose

 

[Zuikkis]

I'm borrowing this old thread. 2013 P85+ here with stuck parking brake. Separate parking calipers.

It's not completely stuck, but it does not retract completely. I only noticed it when the outer pad worn out completely and started making grinding sound..

I removed the caliper. Is there instructions somewhere how to disassemble it? How is the piston "reseted", just rotate it manually or something? There's no way new pads will fit unless I can make the piston go in.

 

[Zuikkis]

Bah, I found great video from an other thread in this forum:

Should be easy to do. And quite easy to clean and grease the gears that show in the hole.

 

[Julian Hsu]

After trying every single tool we could think of turning the piston back and having no luck, we turned to brute force and took out the Club Hammer and hammered the caliper off. It was not for the faint-hearted, but it came off and the car is driving again. There is something wrong with the pin driving the piston. I'm properly going to get a new caliper, but I will be taking the old apart and see what coursed the failure.

Hey rna-e, I am currently facing the issue with the piston stuck and can’t be unscrew from the “Star” nut. Back then, did you literally use a big hammer hammer off the caliper?

 

[Julian Hsu]

Bah, I found great video from an other thread in this forum:

Should be easy to do. And quite easy to clean and grease the gears that show in the hole.

I tried, but the nut is too tight or stuck to allow any winding to loosen the piston at all..

 

[Zuikkis]

I tried, but the nut is too tight or stuck to allow any winding to loosen the piston at all..

Try to use some CRC or WD40 to lubricate the mechanism. The star shaped axle should move very easily, almost by turning by hand without tools. If it doesn't it's somehow rusted in place or something.

If you can't get it moving, you can try removing the locking spring that's visible in your photo, then you should be able to disassemble it. There's a ton of small gears inside so it is possible things go horribly wrong, but in this state I think your only option is to buy a new caliper anyway..

 

[rns-e]

Hey rna-e, I am currently facing the issue with the piston stuck and can’t be unscrew from the “Star” nut. Back then, did you literally use a big hammer hammer off the caliper?

Yes! A big hammer and then just hammer it off the brake disc and it needed some force too. It didn't damage the brake disc and the parking brake caliper had some chips in the paint, but no real damage as well. Got a 'new' used one and replaced it and no issues since

 

[Julian Hsu]

I'm borrowing this old thread. 2013 P85+ here with stuck parking brake. Separate parking calipers.

It's not completely stuck, but it does not retract completely. I only noticed it when the outer pad worn out completely and started making grinding sound..

I removed the caliper. Is there instructions somewhere how to disassemble it? How is the piston "reseted", just rotate it manually or something? There's no way new pads will fit unless I can make the piston go in.

Try to use some CRC or WD40 to lubricate the mechanism. The star shaped axle should move very easily, almost by turning by hand without tools. If it doesn't it's somehow rusted in place or something.

If you can't get it moving, you can try removing the locking spring that's visible in your photo, then you should be able to disassemble it. There's a ton of small gears inside so it is possible things go horribly wrong, but in this state I think your only option is to buy a new caliper anyway..

Hey Zuikkis, thanks for the advice, however, I took out the spring yesterday but there was nowhere to go from there. Luckily, this afternoon, I took out the pen which secure the brake pad, and tried to hammer the entire caliper out, and it came with success! It is all good now from here I actually got a used caliper from the scrapyard and tried to put it on now and see if it works. Finger cross!

 

[rns-e]

Firm hands-on persuasion is sometimes the only solution Good to hear that you are back on the road again