brake shudder (again)

[adiabatic]

Our 98 truck has developed brake shudder again. This after replacing the original drums about 3k ago. Initially I set them up fairly loose and they were fine. Last week I adjusted them up till they dragged, then backed them off about 8 clicks each. (This has always worked fine on our 97, it has never shuddered. )

Now the 98 shudders again.

Has anyone found the real cure?



(Buying a new truck with disks is not an option)

 

[Doc Tinker]

A couple of things to consider, when replacing your brake drums:

Don't buy foreign made brake drums.

Have the new drums resurfaced.

Don't touch the machined surface and clean with brake cleaner before installation.



You might have already done what I suggest and in that case I have nothing more to offer. By following these rules I never have brake shudder problems.





Doc

 

[Bigramguy]

My 97 shudders if I adjust the brakes up fairly snug,yet we have newer trucks that won't. I have to run them a little looser that I would like. One other thing that will make it seem worse is worn rear shocks,or shocks with very soft valving.

 

[adiabatic]

Doc, the new drums came from NAPA (premium) and I was very careful to keep the inner surface clean. I would hope they are true as delivered, I did not have them checked.



Interesting that Bigramguy has observed the same effect of adjustment. Maybe the servo effect is different depending on adjustment, making them too strong, leading to axle oscillation.

The truck in question still has the original shocks so maybe it is time for some stiffer units.

Why some trucks shudder and not others is still a mystery.

Thanks for the replies.