Be carefull when installing new brake pads !!

pcb

The Diagram Dude
:
2002 MP5
I noticed when greasing my front caliper slider pins that my brake piston dust boot had a big rip in it.

I checked my parts car and it had the same rip in the same spot.

These are pictures of my parts car with the brake piston siezed part way out.





I realized that when you install new pads you push the brake piston all the way in and the dust boot ends up sticking out further than the piston then ends up getting pinched between the piston and the edge of the brake pads.

I remember when I did my car the caliper was really tight on the pads and I had to kinda hammer it closed.

I probably had the boot pinched in between.
Oops.





If the boot is torn, water, salt and crap gets in and rusts the piston but only the exposed part which increases as the pads wear then you can't push the piston back in when it's time to change the pads again.



I bought new dust boots for my calipers as well as some Sil Glyde and intend to replace the boots and fill them with the brake grease.

You can use Sil Glyde on brake pistons and piston seals.



 
Last edited:

pcb

The Diagram Dude
:
2002 MP5
Yea, it has nothing to do with the rust.
The caliper is really tight with new pads in it and the boot easily gets pinched.

I didn't take any pictures of my DD so I took some of the parts car.

The original owner got his boots pinched too, so it isn't just me.
 

pcb

The Diagram Dude
:
2002 MP5
I took a couple of pictures of my DD while I'm trying to install my new boots.

This is the torn boot. (it kinda pulled out of the caliper a bit)



The pads are only a little worn so the brake piston is almost all the way in.

You can see how the boot gets caught on the edge of the brake pad.

 

pcb

The Diagram Dude
:
2002 MP5
I got my new boot installed.

I pulled the old boot off (which was "hooked" into the caliper with lip into a groove) then pushed the brake pedal 9 times to push the piston out.
Being careful not to push the brake too many times and blow out the piston.





I sanded the piston with 1000 grit sandpaper to clean it up a bit then put Sil Glyde on the piston.

I rotated the piston with a big adjustable pliers to get access to the whole piston.



Then I pushed the piston back in with a big C-clamp.




Installed the new boot and I'm good to go.

I couldn't get the lip of the boot into the groove of the caliper but it's pushing up againt it and there's lots of grease protecting it.





I don't really recommend doing what I did.
To do it right I should have just replaced all four calipers but that would cost ~$500 and my car is only worth that much.

I don't think my car is unsafe in any way and would probably just leak fuid if it fails but I can't see any catastrophic failure happening.
 

pcb

The Diagram Dude
:
2002 MP5
The drivers side piston boot wasn't torn so I didn't replace it.

I did push the piston out, cleaned it up and greased it.





 
Top