2000 2500 4x4 Diesel
Okay, this is now the second ram I've had that this has happened to. Don't think it's just my imagination now.
So, new front rotors, and pads, fully greased hardware, went together fine. New rear drums, shoes and wheel cylinders. When I'm on the brakes, I've got a shimmy I want to say in the rear, but I'm not sure.
Now, on my old 1500 4x4 I got a shimmy similar to this problem after I did the rear brakes and front brakes, master cylinder, calipers, wheel cylinders. Everything was new, and I had a shimmy.
Now, everything is new, and I have a shimmy. Its irritating the hell out of me. The shimmy happens when braking roughly between 30-15 mph. But, when coming to a slow stop, you can feel something like the drums or rotors are out of round or something. I'd call it a wiggle so to speak. It was doing this wiggle before I replaced the drums and rotors. It was just much worse because the drums were out of round and the rotors were starting to delaminate from my last long haul when frankly I was overloaded. I was expecting to have to replace them.
I had a thought tonight. Is it possible that the wheel cylinders aren't expanding at equal rates front to rear, making one shoe have more contact than the other? How to hell would I go about diagnosing that? I mean, I dont want to take the drum off, step on the brake pedal lightly and have the freeking thing shoot a shoe off.

Ideas guys. Need ideas.

 

If you feel the shimmy in the steering wheel, its usually the front brakes. If you feel it through the floorboards, its usually the rear brakes... I have had some cases where I felt it in the steering wheel, but it was actually the rear brakes, so check both front and rear for excessive runout. Check caliper slides to see if they are seized, also lubricate those. Check for correct adjustment on the rear shoes, if not adjusted right, adjust it. What you can possibly try is bleeding the brakes with a pressure bleeder, that way you can for 1, make sure no air in the system, and 2, you can also eyeball it to see if there may be a blockage in one of the lines.

Hope that helps. Good luck.

 

And this is why I routinely turn NEW drums and rotors before installing them.

 

Caliper hardware is fully greased and functioning well. I replaced the slides and pins every time I do a brake job. Cheap assurance i suppose that the hardware is good.
Adjustment on the shoes is correct, the adjusters aren't seized. light drag on the drums as it should be.
I dont feel the shimmy in the steering wheel, i feel it in the floor and seat. I know that trick about front or rear.
I guess I will check the drums for run out.

 

Update:

One of the drums I got was cast wrong and way off balance. One new warranty drum and some machining and she stops like a dream again.

 

Thanks for posting the fix for your problem!!!

 

+1... Thanks for the update.

Problem solved.