Do plastic caliper pistons swell/seize?

[atikovi]

Posted before about my 2003 E450 box truck that's only been driven 600 miles the last few years and that the left front caliper is sticking. Replaced the brake hose and it's 75% better and it doesn't pull to the left anymore, but I can feel the left wheel much hotter than the right after a few miles drive. Lifted the wheel off the ground and I can't turn it. Opened the bleeder and no unusual pressure. So I take the wheel off and remove the caliper to check the slide pins. They are fine. Take the caliper off the hose and to the bench to take apart, Get the piston (plastic) out as well as the seals. Even with the seals out I can't press the pistons back in. Do they swell? Can I use sandpaper to reduce the diameter or will that just mess them up? A new pair is only $17.

 

[eljefino]

Had this exact thing happen on my 95 f150 that gets similar mileage to yours.

I didn't blow it apart- just got another from AA that works fine. Figure the rubber seal etc was old enough to warrant shotgunning.

 

[Donald]

I would only replace a part like a caliper piston or slide pin. Never sand or wire brush.

 

[Silverado12]

Mopar had this problem on Dakota pickups and maybe others. I got new calipers from NAPA.

 

[Linctex]

I bought new phenolic caliper pistons on RockAuto on clearance for like, $3 each?

 

[bionictony]

i never heard of phenolic pistons until i serviced my brakes. i heard they do swell up over time and seize. i'm looking to switch over to metal pistons or calipers with metal pistons