ok...here's the history...
99 1500 5.2 4x4 automatic..
brakes have been fine, no issues, until i discovered a blown wheel cylinder in the driver's side rear drums.
replaced the wheel cylinders, shoes and drums on both sides in the rear.
take it out for test drive and after a few minutes noticed very violent shaking when breaking...shaking the entire truck...
thought it was coming from the front, thinking the front rotors warped from working too hard since the back brakes were not working.
so we put on new rotors and pads...still shaking...thinking caliper was sticking, so we put on new calipers...still shaking...
new thought, maybe we didn't get all the air out of the lines in the rear..so we bled the rear brakes again and also pulled the drums and adjusted the rear brakes...still shaking...

not sure what to check next...Rear ABS?? Rear Axle bearings??

couple other notes...after the brakes shake...if we drive in reverse and brake (no shaking) and then drive forward, the shaking stops for a couple uses of the brakes, but then come back. Also, the driver's side adjusting lever doesn't come in contact with the star wheel on the adjuster, looks like the horizontal spring above the adjuster is just barely in the way.

from all the few pictures we could find on this brake setup, everything appears to be installed correctly (not new at this, been working on and restoring cars for 20+ years)...again...just baffled...

any thoughts?

 

I had a similar problem on my durango a while back. turned out to be the rear flex hose was deteriorated which created a flap that worked like a check valve and would hold light pressure on the drums which caused a massive vibration. does it go away if you let the truck sit for a little while?

 

we let it sit for a few days and it never went away....
this immediately started right after we replaced the rear brakes (cylinder, shoes and drums)

one other thing to note...the brake drums...one has a large weight welded to it (for balancing) but the other drum did not....there is no noticable vibration while driving....

 

if thats the case i would have your drums checked for out of round (i have had several new sets at the shop that were way out of spec from the manufacturer). check the shoes to make sure there is no damage to the linings and that the primary and secondary shoes arnt mixed up. the tops of the shoes should fully contact the anchor when the hardware is installed properly. also make sure you didnt mix up the side the shoes go on.

 

also did you let the line run empty when you changed the wheel cylinder? if air got in the abs actuator it will cause problems like this. you would need to have the abs cycled by a factory scan tool a few times to get it out. ive heard panic slamming your brakes can get the air out but isnt very effective.

 

pulled the main ABS fuse, still shakes...

is there a "left" and "right" side to these shoes?

 

No, but there is a definite front, and rear. Short shoe goes to the front.

If this all started right after you did the rears, I would check and make sure you have the shoes on correct, and if you do, take the drums and get them turned.

 

Hey You is correct the short front shoe is the primary and the long rear is the secondary. When you apply the brakes the primary show creates a wedging action and forces the secondary shoe harder against the drum having them mixed up can cause some strange brake problems. I would double check all your hardware to make sure nothings binding and that its all in its proper place. It might also help to put some white lithium grease on the shoe seats on the backing plate. if they are really dirty or rusty they can keep the shoes from returning.

 

Always turn new drum and rotors, had pulsing and shaking on 50% of new rotor drum installs.

 

Thats gonna be our next step, take the drums back and have them checked/turned