81 c10 brakes sticking

[Isaiah molina]

I've got an 81 c10 that has been sitting for a year or two. I got it running but now I'm having issues with the brakes. It has a new master cylinder and I replaced the calipers because they were siezed. When you hit the brakes normally the pistons dont move at all. When you really lay on the brake pedal the pistons will engage but then won't retract. I was thinking maybe theres a proportioning valve that's failed. And ideas?

 

[Dmack]

You usually can't see the caliper piston retract. Pressure is released and the slight movement of the disc moves the pads out of contact minutely.

 

[Isaiah molina]

Yeah, but when the pistons do engage they just wont let got at all and the rotor wont turn. And if I pry the caliper off I cant press the piston back in.

 

[1985c20]

Did you replace the brake hoses? They can collapse inside and act like a check valve. To test this, press the brake pedal down and when the brakes are stuck applied open the bleeder screws to relieve the pressure.

 

[Honky Kong jr]

Congrats guys, new members with intelligence!!!! Parts are cheap replace the hoses and calipers total job may cost you less then 100

 

[Isaiah molina]

The rubber lines are about $15 each so I'll go ahead and replace those and while I've got them off I'll try and pump the brakes and see how much fluid I get out of the hard lines and decide whether I need those too. Probably wont be for a little while but I'll post updates when I get to it