I have had a rear brake shudder in my 1997 for about 16 months now and I can't trace the problem. I wanted to upgrade the vehicles suspension and brakes and figured the problem would be resolved with the upgrades and refreshing but it hasn't happened. When I apply the brakes, there is a pulsating at the pedal and a shudder that's pretty bad. ABS light has been on since I bought the truck 16 months age. Here's what's been replaced or tried.

Pulled ABS relays and fuses.
Replaced entire brake hardware front and rear including hoses, calipers, front discs, drums, shoes and pads.
Replaced entire rear end with one that was absolutely perfect.
Replaced rear leaf springs and shocks. Still running original shackles which do have worn bushings.
Checked frame for cracks.
New u-joints
New tires and wheels. Have tried 3 sets and none have fixed the problem.

Clue: Truck is a standard transmission. When I decelarate using just the transmission braking, it does not shudder so I think the transmission bearings and bushings are not a contributor.

Any ideas? It's the only element making an otherwise nice truck, drive great.

 

Seems like you got your rear end covered pretty well yes pun intended sorry couldn't resist

Have you checked the tranny mount? see if it is cracked, decayed or loose.

Have you had the drive shaft checked for balance?

Are you sure that the engine isn't giving a misfire and It just feels like it coming from the rear?

Does this happen only at certain speed MPH or RPM?

Is there check engine light on?

 

Thanks for the response. It only shutters at braking. Otherwise it runs smoothly. The transmission mount seems fine but I'll try changing it.

 

No use changing the mount if nothings wrong with it.

 

thanks for the clarification, in light of that I agree with JCR 56, that if all appears good I doubt that is the issue....you might have to get a bit extreme, and mount a gopro or a similar small camera and video key components and repeat until you can zero in on whats is shaking/shuddering.

Have you replaced the ABS module itself? not just fuses and relays
Have you re-blead the brakes lines to make sure all the air is out?

How does the brake pedal feel? firm or kinda soft.
Have you checked for vacuum leaks?

 

With rubber mounts it's easy to miss a hairline fracture. I have a new mount and was going to replace the old original anyway. I have not replaced the module. I purchased the truck as a mechanic special with a hydrolocked V6. The fuses were already removed and the rear electrical line to the ABS cut so I suspect the truck had issues when I purchased it. A replacement module might be in order. I added braided steel brake lines to compliment the EBC Green Stuff pads and made the problem worse so I suspect the module is the problem even though it's deactivated. Now the pulsating I feel at the pedal is harsh. Don't know enough about how ABS works.