So I decided to upgrade my brakes on my EM1 to Brembo blanks with Hawk HPS pads. I did the installation this past weekend, but ran into a problem when I tried installing the rear caliper over the new pads. There wasn't enough clearance because the piston wouldn't sit flush with the caliper. I tried using a C-clamp to get the piston to go back into the caliper, but after a certain point (about 1/4"), it wouldn't budge. I didn't have this problem with the front calipers. The front pistons went in really easy. But the rear ones were a pain in my a$$. A buddy and I spent a couple of hours trying to get the piston to go in, but we had no luck. We ended up putting the stock pads back in just so I could get the car back home.

Has anyone else experienced this? It looks like the E-Brake unit is built into the caliper, and we were thinking that the issue had something to do with this design. The E-Brake wasn't set during the install, and we even tried releaving the brake fluid pressure in the line. If anyone else has any ideas, I would really appreciate it.

I tried searching, but most of the hits were about rear disc brake conversions. We found one that was useful, but it said to use a C-clamp, which we did.

 

You probably broke the rear calipers. They screw in (hence the cross-pattern marks on the caliper piston surface) and if you made them move at all with the C-clamp, you 99% fucked them up.

Maybe do a little research next time so you don't break parts, hmmm? It's possible that you only damaged the rear calipers, but it's unlikely. I won't be surprised when I see the thread from you, "Rear brakes not working right! Help!" in the near future.

 

Correct, they screw in just like a screw/bolt.

 

Well that sucks. With all the threads that I read about changing the brakes, not one of them mentioned screwing in the rear piston.

So, can you be a little more elaborate on what kind of damaged we may have caused? Striped threads? No longer sealing and not functioning? Torn seals? The rear pistons appeared to push just fine while we were bleeding the brakes, and there were no leaks after we test drove it.

I did notice on the test drive that during one of the hard stops from 50-0, the rear brakes couldn't keep up with the front brakes, which caused the rear end to come out a little bit. But that only happened once, and I just assumed it was due to having stock pads in the rear and HPS in the front.

Thanks for your help!

 

Can you comment on what type of damage I may have done to my calipers?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jadmEM1 &raquo;</TD></TR><TR><TD CLASS="quote">Can you comment on what type of damage I may have done to my calipers?</TD></TR></TABLE>

Irreparable damage. New caliper time