Wierd Brake problem - ABS, MC or Hydro boost??

[jimmysauter]

So my brakes have been acting up for a while now. (rear ABS only) It is kinda intermittent.

Under heavy braking, the pedal will sometimes release and re-apply like the ABS is kicking in, but it is dry out and the tires aren't slipping. And the ABS light sometimes comes on, which will reset when the truck is re-started and then doesn't come on for a week or month or longer.

Then under normal steady braking, the pedal will slowly step down say 1/8" at a time every second or so. This usually happens if the brakes haven't been applied in a while.

Anyone seen similar issues? Also, my power steering is horrible(can't turn when truck is stopped, and have to rev engine at low speeds to turn), but that seems to be par for these trucks in general. Where should I start at with throwing parts at it? Master cylinder, rear ABS sensor or valve, powersteering pump, ... Thanks

[AgentAustin]

You should be able to turn the wheel when at low speeds, I have no problem doing dry turns when I am stopped, not normal...

IDK about the brakes.

[jimmysauter]

I just determined that if I apply the brakes during low speed turns it locks the steering, which seems like a bad PS pump and not getting enough flow to the whole system.

[alk8778]

I've been having a similar issue lately. I have attributed the abs kicking in during slow turns to the locker i have in the rear, but it has not always done this. I'm also noticing the braking is not as good as it used to be. I just tore down everything and replaced pads but no improvement. I have a feeling these issues are related so any input would be awesome!

[jimmysauter]

I unplugged the ABS fuse for a test drive and the brakes worked like one with out ABS. The rear brakes actually would lock up pretty easily on dry pavement, and I could slow down better.

I think what is happening is that in those situations even on dry pavement, where the brakes lock up, then the ABS kicks in, but it either stays on too long or doesn't apply enough pressure as it is pulseing, so it actually takes longer to . I am still trouble shooting, and put the fuse back in cause my windows and remote quit working with it out. Disclamer: Don't drive on the road with the ABS fuse removed.

I am going to look at the tone ring eventually and ABS sensor to see if they have rust or build-up on them causing false ABS signals,...