Rear brake shudder

[85 Squarebody76]

Say I am having a problem with braking on my 1985 GMC 1500. Power disc front and drum in rear. When I apply moderate braking the back end has a tendency to shudder and start hopping. I have replaced the brake shoes and turned both rear drums. Had the all the tires balanced. If I brake gently there is no problem but moderate or hard braking causes the issue to happen. I pulled the drums off and made sure all is dry and clean and adjusted correctly. Has anyone had a similar problem ?

 

[Vbb199]

Back the star wheel off a tad, they could be a touch too close to the drum and grabbing too hard.

 

[mtnmankev]

And the short brake shoe goes towards the front and the long shoe to the rear ?

 

[85 Squarebody76]

Back the star wheel off a tad, they could be a touch too close to the drum and grabbing too hard.

I will give that a try... Thanks for your

 

[85 Squarebody76]

And the short brake shoe goes towards the front and the long shoe to the rear ?

Yes the short in front and the long in rear... The problem started with the factory shoes. I thought maby new shoes and turning the drums would correct the prob... I am the second owner and it has 55,200 original miles on it...Thanks

 

[GMCSHOPTRUCK]

Did you resolve the issue with rear brakes? I'm having the same issue, was thinking drums could be warped!?

 

[85 Squarebody76]

Did you resolve the issue with rear brakes? I'm having the same issue, was thinking drums could be warped!?

Have not found the problem yet. New brake shoes and both drums turned. If I have weight in the bed it brakes smooth as butter but when empty it starts jumping

 

[fast 99]

shocks or other suspension bind?

 

[GMCSHOPTRUCK]

My truck also starts jumping when hard braking, thanks for the reply

 

[BKING33]

Double check that your e-brake cables are releasing properly. I had 2 different trucks that would have brake problems after using e-brake.

 

[IdahoJOAT]

Yeah I'm curious if it's a leaf spring issue. When under load it doesn't do it... so I'm wondering if a spring bushing is bad. When the rear brakes, the one side comes forward, throwing everything out of alignment in the rear and causing hop. I would think the bushing would have to be pretty bad though to cause what you're describing. Interesting.