Brake Problem (Grabbing, Not Letting Go)

[VerbalKint]

Ok.. Lastnight, figured out what was causing the excessive vibration when I drive around as mid-range speeds (30-60).. And I DO Mean excessive vibration.

Got Home..Smelled hot brakes.

Quick inspection.. Front Driver Tire.

Jack front up, support car, remove both tires.
Slip car out of gear... Passenger side rotor rotates freely, just as it should...
I could NOT turn the driver side rotor. Took the caliber loose (Not the whole thing, just the part that swings down over the pads), and after having to open the bleeder valve to get some slack, finally get it to come up.

Pads still have material, rotor has no gouge marks on it from excessive wear (weird, i know)

I reopen the bleeder valve and get the caliper piston pushed back in, and reassemble the unit.

--snip-- bled both fronts, to make sure no air got in system --snip--

Check.. Rotor spins freely.

Reassemble car.. sit in driveway with car running, working the brakes, making sure everything is set.

Test Drive.. few minutes below 20 mph, just in case something goes goofy.
All goes well.. Crack 60 mph on the way back to the house (On highway) YAY.. No steeringwheel shake, no front end shake, no vibration other than normal road noise.

This morning, go to work, vibration starts to come back, I have a sneaky suspicion its the same thing. I will be replacing that caliper this weekend, but mainly, I am wondering a few things.

1: What would cause a caliper to grab and not release like that?

2: Can I assume the caliper is at fault, and not some other part of the brake system? (Visual and mechanical check of the other 3 wheels show no problems apparent with them)

 

[DiabloRT]

I had a similar problem....I after installing stainless briaded lines and bleeding the system, the problem still existed.

Changed out the offending caliper and that took care of things. Although a caliper rebuild kit would probably do the trick.

 

[RED&BlackGSX]

If you took the bleeder screw loose, and it shot fluid, then the brake hose is the problem, if it did'nt shoot fluid and was still locked up, then the caliper is to blame. Also, the guide pens, can sieze up because of lack up of lubrication. YOU MUST LUBE THE GUIDE PINS WHEN INSTALLING THE CALIPERS OTHERWISE THEY WILL SEIZE UP LATER!. and may cause the problem you are having now.