Shudder RWD Braking in the Air

Did the lifted brake test to ensure my drums are installed properly. Brake pedal press successfully stops the rear wheels on both sides, but the truck experiences a shudder when I hit the brakes. No shudder when releasing brake pedal, no shudder when actively braking (the rear wheels don't lock up instantly, instead they slow down to a rapid stop). Only getting shudder for the first second after pressing the brake pedal. No shudder experienced when driving.

Is this normal?

Truck is up in the air, lifted all 4 wheels.

 

Antilock brakes?

 

My ABS is disabled (ABS light is on ever since I bought the truck).

 

My best guess is that it's out-of-round drums.
Guess #2 is that the drums are round, but the brake shoes are not engaging evenly. Is this a possibility or is it probably just option 1?

 

You said it only does it on initial braking but not while holding down pedal right? Have you driven it yet to see how it feels? I've definitely seen brand new drums warped on a tundra. What brand?

 

How was the truck lifted? Did you have the jack stands under the axle so the suspension was still compressed? If the suspensions decompressed it could just be because of the LSPV being unloaded


Assuming all 4 wheels means it’s on a lift..

 

Yep! Only on initial braking, not while holding the pedal down. When driving the braking feels completely normal which is why I never noticed it until now.

It's the full Power Stop Z36 package, drums and shoes. When I bought it that's what I discerned to be the best.

 

Yessir, lifted all 4 wheels in the air. Jack stands are under the axle tube on each side of the rear diff pumpkin.

 

Ah so suspension was compressed. Could just be slightly out of round drums. If you don’t feel it while driving I wouldn’t worry about it