Brakes lock up

[Rhine620]

So I'll be driving then my brakes will start to gradually lock up until it won't move then have to get out and open the brake bleeder vavle on any tire doesn't matter and it will start rolling again could this be the brake booster? And also when I apply pressure to the brake pedal when truck is idea long it will die?

[kelowg]

i suspect brake shoes dragging or moisture in brake fluid. my 521 did this, went thru brakes and lube all pivot/sliding point with anti-seize compound. that seemed to work.

[datzenmike]

Which wheels are locking up? Front or back? The front's are separate from the backs so opening one bleeder shouldn't work for both.

 

Have you replaced any brake parts recently? as these things rarely start by themselves.

 

 

 

Check the pedal free play. Push down on the pedal with your thumb. It should move easily for several mm or 1/16" before firm resistance is felt. If no play the push rod between pedal and master cylinder can be adjusted.

[laotsu]

try pulling back on the brake pedal with the tip of your toe when the pressure has built. My push rod is just a little out of adjustment and this releases the pressure.

[Marsh510]

I am currently experiencing the same thing on my 510. The rear brakes are locking up on me. Have no idea. I have already replaced both wheel cylinders also if it makes a difference. Running stock drums.

[ggzilla]

Adjust the pedal rod. The spec is in the repair manual.