Inconsistant pedal height on bumpy roads

[aipaul]

I'm having a brake problem that I can't figure out. Whenever I drive on bumpy roads, the brake pedal goes down almost to the floor when pressed. After pumping once or twice it returns to normal. I've changed the front calipers and master cylinder so I suspect it something to do with the rear brakes. Could the springs in the rear drums be worn out causing the shoes to move around on bumps?

 

[pimtool]

If your wheel bearing are loose enough they can wabble the tire and push the pistons back into the calipers. Check for any kind of movement with the tires off of the ground.

 

[aipaul]

Thanks pal. Loose wheel bearings was exactly the problem. I was skeptical at first because I just tightened them a few months ago. I wish there was a better way of locking the wheel nuts on manual hubs. They alway seem to loosen after a while.

 

[pimtool]

I am glad it was something simple. Not alot of $$$

 

[pillen140]

they make that warn kit! i dont have it, but ive heard good things.