95 GMC Sirerra 4X4 Inconsistent brake pedal

Bought the truck used with 155,000miles. The brake pads were replaced all around. Brake hardware on rear was replaced and drums turned. Master cylinder was replaced. ABS module was replaced. System bled several times.
I continue to experience inconsistent brake pedal. Sometimes the pedal has very little travel and other times it goes halfway to the floor. No lights on panel suggesting a problem with the system. Sometimes I get a feeling that something is out of round beacuse I detect a wobble/hop when braking, but that doesn't happen all the time either. All wheels/tires are tight. Need suggestions as to the cause/fix. TIA. TomC
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Could be that the rear drums were turned past they're maximum diameter, and are a little out of round because of this.
Brian
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all
times.
has
lights
feeling
braking,
tight.
and

Rear drums were turned at a parts/machine shop because they were out of round; plenty of metal left; but, thanks for the input. TomC
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I had a somewhat similar problem on my truck not quite as severe, but have you made sure your rear brakes are adjusted properly? When I first looked at mine, there was literally a 1/4" btwn the shoe and the drum.
Do you have hydroboost or vacuum brakes? If hydroboost make sure you have enough power steering fluid. Have you had any power steering issues at the same time?
TomC wrote:

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When I replaced the rear hardware, I adusted the shoes as close as possible. Once the drums are on, there's no access to the adjuster (Weird setup); so, I have to rely on the self-adjuster to tighten them up. I recently had the truck inspected (Pa.) and the mechanic adjusted the parking brake for some unkown reason. Seems like there's more free play in that now, but I don't think it should affect normal braking.

Vacuum brakes. They're kind of hissy when applying the brakes. Normal?? TomC

pedal
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Sometimes when I encounter this problem I am able to 'cure' it by making several ABS assisted stops. You can do this on a wet road or better yet on a dirt road. get some speed up and slam the brakes on till you stop, oh, make sure you take all of the potential flying objects out of the truck :-0! Seems that some gunk can get caughtup in the valves and what not. Some trucks take more than 20 ABS assisted stops to 'fix'.
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on a

make

Yes, I did that last winter on the ice. I understood that to be a fix to get air out of the ABS system. Worked for awhile but, it didn't last. :-(
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