kwm1971

I changed out my passenger front caliper last wednesday when it locked up. I then replaced my driver front caliper monday when it locked up. I had a bad vibration Today from 48-55mph which revealed the back driver side caliper dragging. Ive replaced 3 and may have the 4th acting up. What is going on? the back brakes didn't lock & smoke, they just shake the back horribly

johnny_tucson

did you flush and bleed? What year? How many miles?

kwm1971

2005, 140k, installed brake lines, opened bleed screw till fluid flowed. Closed screw. Worked brakes

lewissa81

You need to force the air out. Either get a friend to help, or a vacuum pump with a brake bleeder kit.
With a friend, attach a clear hose to the bleeder. Have him (or her) slowly push the pedal. When he does, open the bleeder. When the pedal gets all the way to the floor, close the bleeder quickly. Keep doing this until there are no more air bubbles coming out.
With a pump, (I use the mighty-vac), pump it up a to some vacuum on the bleeder, then open it up. Watch the guage and close the bleeder before the guage hits zero. Do that until there are no more air bubbles.
It's quicker with a friend pumping the pedal though. Those are just my two methods. I'm sure other people will have their own.

wOrker

I recently had my brakes lock up, and am still trying to fix the issue. I believe it's collapsed lines as I replaced all the calipers, pads, master cylinder, check valve.

Your issue may be, once the brakes started grabbing - they heated the rotors so now when you brake you get vibrations?

Are the brakes still slightly grabbing?