Brake pad replacment (pesky pistons)

[stateofidleness]

How in the HELL do you get the pistons pushed back in the caliper??
I got everything all dis-assembled, got the new rotors on, everything is going swimmingly...

I opted not to do the fronts only because the fronts looked fine (were good pads, Brembos) and I didn't have the new pins/clips etc (not a big deal). When I got to the rear, they were more worn, so I figured I'd do them while I had it all apart...

Get the old pads out and following numerous tutorials about using a wood block or metal rod to push the pistons back in, they aren't moving at all. I didn't want to rip any seals, but I was pushing pretty hard and they weren't moving at all...

I read one tutorial that said something about opening the bleeder valve, but I REALLY didn't want to have to bleed the brakes and all that if I didn't have to. My pedal feel is great and I don't want to disrupt the harmony

I read something about a tool that can be used for this ( a "pad spacer") but haven't gone to the FLAPS to find one yet. Do they work?

What's the trick here?

[ekam]

Use a C-clamp but make sure you cover everything with a piece of cloth so you're not scratching/dinging anything, also open the brake fluid resevior.

[kabel]

mechanical leverage is often needed... I bought something similar to this
Brake Pad Separator:
http://www.grainger.com/Grainger/KD-TOOLS-Brake-Pad-Separator-2ZPN2

[stateofidleness]

if I open the brake reservoir (the tank in the front, not the caliper right?), do I need to bleed when I'm done?

kabel, did that tool do the trick? would the tool + tank open be the solution?

when I did the "wood" thing, it didn't seem like they wanted to move AT ALL!

I'm having trouble envisioning the C-clamp method on our calipers... how's it setup?

[thstone]

+1 on a using a large C-clamp to push the caliper piston back in. Use a thin piece of wood or one of the old brake pads to cover the piston so you have a nice flat surface to push on with the clamp. Cover the back of the caliper with a rag or something soft to avoid damaging the surface of the caliper (especially if they are painted like mine are).

Open the brake fluid resevoir (tank in the front trunk) to lessen the pressure as the fluid is pushed back into the resevoir as you push the piston back into the caliper. Be sure that the resevoir doesn't overflow as you're pushing the piston back in or you'll have a nice brake fluid mess in your front trunk.

It might take some pressure on the piston to get it to move back into the caliper but not a huge amount. Try using a slow and steady pressure so the fluid can flow smoothly back into the resevoir - if you try to give it one big push it ain't gonna move at all.

If you can't get the piston to move at all, then you may have a frozen piston and the caliper will need to be removed and rebuilt. This is pretty rare.

This is a pic of the general idea of using a C-clamp...

[stateofidleness]

I can't see how to rig up the C-clamp on the boxster calipers though. I see pictures of it being done on other cars, but the calipers allow the "bar" part to go "through" the middle of the caliper.