Newbie Changing Brakes on 2008 M45

[JacopoBelbo]

This forum is great and the info provided is very thorough.

I have several German cars (Westy, 911) I like to tinker with but I recently purchased a 2008 M45 Sport with 50K miles. I thought I'd change the brake pads and rotors myself so I read what I could find and watched many videos. However, when I could not remove the rotor (after 30 minutes of banging) I thought I would double-check the parking brake even though it was disengaged. I thought I'd put the car in neutral and without thinking I started the car, put it into neutral, saw the wheel spinning and turned the car off. In doing so the piston popped out of the caliper...which made me rethink the entire DIY option. I did finally remove the rotor.

My question is, does that boot come off of the caliper or is mine melted on there? If no, then can someone please recommend how to reinsert the piston? I know how to do it with the boot off but with it on it seems tricky and I feel like the boot will tear. Also, did I potentially do any other damage? Thanks in advance.

[Ilya]

Welcome to the forum.

Do you have some pictures? Honestly this is a new one for me...no offense. Try to get it all back together and then read the FAQ thread in my signature which has many DIY threads with pictures (including how to do brakes that I wrote).

[BlackCat81]

Run to Carquest and buy a new caliper. They're cheap and have a lifetime warranty. It'll save you a lot of time rebuilding it. Replacing it is easy, we can walk you through bleeding it if you decide to go that route.

[Ilya]

Actually, that's a smart idea to just replace the caliper. They really aren't all that expensive. That way, all you need to do is just remove the bolt holding the brake line to the caliper (warning: you will leak brake fluid so be ready) and just install that and a new crush ring or whatever (new caliper should come with it) on the new caliper. Fill up brake fluid reservoir after done and bleed the system.

[JacopoBelbo]

Thanks for the advice to buy new. I may go that route tomorrow halt although I am curious as to whether or not anyone has removed the boot before to install the piston into the rear caliper. There is also a piston seal and retraining ring that I can't locate anywhere. Is the seal what's securing the boot in the caliper? If this is too much more trouble I'll head to the store but I know that on my old Ford truck I could compress that piston back in there with a c-clamp. Thanks in advance.

[Ilya]

I've compressed many a piston with a c-clamp, but I've honestly never seen a piston come out like that completely. Unfortunately, I don't know how you'd go about getting it back in there. Perhaps one of our other members can chime in for ya...