Rotors getting VERY hot

[NebRanger]

Thanks for the tips guys. I believe it is 4 wheel abs, 2 lines from master to abs and 3 lines out of the abs (2 to front wheels and 1 to the rear).
, both wheels seem to be affected the same, so something at the top end that is common to both, I would think

 

[55trucker]

Recreate the situation again.....when the truck is driven & all is hot under the hood... do the rotors drag to a degree? .......get the fronts up in the air & try to turn the rotors by hand, if they are dragging back off the retaining nuts to the master cyl, half a turn should be enough, does the situation lessen?...if so you've found the source of the issue, the master cylinder piston isn't coming to full at rest & the transition port is partially blocked causing a pressure build up when everything gets hot.

 

[Shran]

Should have four wheel ABS. My old 89 had either a bad master cylinder or a bad ABS valve, the brakes would lock up solid after driving a mile or so. Let it cool off and it would move again. I deleted the RABS valve (not advisable in your case) and replaced the master cylinder at the same time so I'm not sure which one actually caused the problem but one of them did. Zero issues after that. Had trouble with the RABS valve on my Explorer too but it was leaking and causing weak brakes.

Might not hurt to go through the rears and make sure the adjusters aren't rusted solid, wheel cylinders are free, parking brake cables free... Not sure if you ruled all that out already, I skipped ahead a couple pages.

 

[NebRanger]

Another update... A week ago, I adjusted the pushrod on the booster, I backed it off about 1 1/2 turns. Didn't take a measurement, as I couldn't get my caliper in to get a measurement without disassembly of the lines to the master cylinder. I now have a much better pedal travel distance, (not perfect, but better). The rotors are in a much better place as far as temperature as a result.
So, 2 birds killed, because obviously my measurement wasn't correct to start with.
The brakes still seem a bit "grabby" at the far end of the stroke, but it is tolerable for now.
I'm probably going to live with it like this for the near future, as the temps here in Omaha have been, and will continue to be frigid. We're looking forward to more days of sub-zero on the horizon, and I am pretty good with how they feel right now, so no, I'm not going to try to heat the garage in these temps.
When the weather gets a bit more tolerable, I'm going to inspect the whole system, front and rear to see if I am missing something.
For now though, I want to thank all of you for your help and input

 

[55trucker]

Good to hear