Darien

Should all 4 pistons have the same amount of travel at the same time??? I pulled the wheels off and applied pumped the pedal 5-6 times and this is how they look!! This looks a little scary

hacker-pschorr

I think the two same size pistons should move together, but without any resistance (brake pads) I'm not sure how accurate this test is. If you keep pumping, will they eventually catch up?

I have stuck pistons in my brembo's, causes some unsteady breaking at about 135mph on the track. Street use I cannot tell anything is wrong. This weekend I'm going to pump a few bottles of el-cheapo fluid through them, then flush again with Super Blue, hope they free up.

FBIII

Why would you do that? Now you have a much greater problem of trying to push them back in without getting cocked.

928drvr86.5

This test means nothing. Piston force under load is really what you are concerned about. The best way measure piston force would be with a compression load cell between the inboard and outboard pistons.

Darien

Yea, yea, I know I only wanted them to move slightly and the top ones slid all the way over, don't worry, I'll get it back

Darien

Thta's all I needed to hear for now I'll get deeper into the calipers when I have more time. I was trying to get the pistons out enough to clean them. I've got one or more sticking

928drvr86.5

You could strain gage the rotor and measure lateral deflection as well, that would tell you which side is stronger. Piston pressures should equalize on all four though, so i doubt you would see any deflection.

piccardo

I would not do that because you are exceedig the normal travel of the piston. If you applied more pressure to the pedal they would equalize.I would not expect the pistons to travel the exact same distance as the fluid will take the path of least resisitance and these pistons while very close in tolerances are not exactly the same.

hacker-pschorr

My mechanic recommended I have someone push on the pedal as I work the pistons back and forth & using a ton of brake clean to work them loose. Then a good flushing of brake fluid.

Darien

When I get ready, how do the front caliper come off? I didn't see any other threads discussing it?

heinrich

what he said

Shane

Two bolts on the inboard side.

MarkRobinson

You'lll need multiple long/flat screw drivers (if nothing else) to pry those pistons back in at the same time...lots of fun!! Or, remove calper, put old pads in, then pry against the pads in an X configuration to return the pistons, then swap in new pads & replace caliper.

Gretch

Use a C clamp instead. Much easier.

928drvr86.5

yep, C clamp! Put rags on the face of the caliper though so you don't mar the finish.