Anybody ever come across a cracked / broken piston when doing a brake job?

Finally had to put new pads on. The guys at NTB told me the RR was down below 2mm and wanted to do the job at their rates... yea right.

When I popped the RR caliper off the pads were a little thinner than the rest, but I didn't notice anything. As I went to push the piston back in I noticed two cracks. Basically a V notch about 3/4" on a side. As I pushed I started getting fluid. Kept it up high till I got back with the new caliper, $43.00 @ O'Reilly, Swapped it out and bleed it.

In the past 25 years in doing brake work I've seen little nicks, but never such a big notch cracked out of the piston.

Truck was hit on the opposite corner last fall, but as far as I can remember it's never been hit on the RR.

 

never heard of a piston cracking before.as far i i knew they only leak when the seal around it goes bad.

 

At approximately 37500 was in the dealer for a oil change. Service advisor came out and told me, I needed new brakes on the rear. I thought boy not many miles on the truck so I asked if I could see them-just to make sure I wasn't about to take one in the rear. Looked at them, and gave the okay. About 15 minutes later he was back, saying the piston caliper was cracked. Went back took a look --two deep cracks about an inch apart. Talked to mechanic-he stated not the first one he's seen on new F150'S. Mine was the driver side rear. Turned out to be an expensive oil change!

 

yeah, sounds like your gunna need a new caliper

 

Forgot to mention, THE PISTONS ARE PLASTIC !!!!!

The guy at Oreilly's pointed it out when I picked the new one up. It looks like steel, but scratch it with my fingernail and sure enough

 

Yeah a lot of pistons today are plastic AKA Phenolic pistons. Whenever you see phenolic pistons make sure not to used a c-clamp or channel locks directly on the piston or it will crack.

 

I had a cracked piston on my 05. Ended up getting a new caliper at Napa and all is good.

 

yea my 96 crown vic p71 has phenolic pistons. i went to replace the front pads and the autozone guy asked" plastic or metal" i assumed since it was a ex cruiser they were metal so.. they looked like they were lol... got the pads took them out of the box.. no fit lol. i always doublecheck now.

 

I have actually broken 3 calipers each one had shattered pistons,this is basically the only thread I can find on this so any new info on what could cause this would be awesome. Oh and I push them in with my hand not pliars or anything.