2001 Dakota Qcab 4x w/ rear wheel abs.
After stop and go driving, the front brakes only start locking up. Can jack the front up, can't move front wheels. Checked calipers, slides and pads, they are okay.
Crack the bleeder and they free-up.
What do you think? Moisture influid, master cyl.?

 

Is it both brakes or just one?? I had a similar problem not that long ago with a rear. When I released the bleeder my brakes didn't release. That meant it was the caliper. Now if it had released, I was told that the rubber line was bad to the caliper. Not sure in your case if that is the same, but it may be a possibility too.
Hope you get it figured out.

 

I would replace the brake hoses.

 

change ur hoses, you grease the pins and stuff when ya had it all apart rite?

 

its the flex lines

 

I had that problem on a 95 Neon i had. it was the hose to the caliper.

 

Think I found the problem.
The rear brake shoes looked okay, but decided to checkthe operation of the rear brakes anyway.I used a long 2x4 to push the brake pedal while watching the l/r shoes. No movement at all, r/rear was okay. Started w/ bleeding, but no fluid from the bleeder at all.
Checking further I found a pinch in steel brake line going to the wheel cyl. Replaced the steel line and then road tested, so far so good.
That means the fronts were doing all the work.
Being that both frontswere locking up, it seems a brake hose would cause only one side to lock-up.
Thanks for the replies!