One thing you may have not tried is check your rear Differential see if it’s low or in desperate need of changing.

The ABS sensor reads notches in the gear set is my understanding it’s possible that if your diff oil is nasty or very low it may throw things off.

Worth a look anyway if the rear Diff oil has never been changed then you can check those sensor teeth for damage you never know it could be the problem.

Just one more thing to check out its only new oil and a gasket

 

Right now I'm waiting on the weather to improve and I really appreciate all the suggestions. I'm going to replace the brake line hoses next and remove the Master Cylinder to make sure I have no leaks there and it's working properly. The Master Cylinder is only 7 months old and was purchased as a re-manufactured. I may just change it to a Brand New Unit. I've heard bad things about re-manufactured Master Cylinders.

I also considered the CAB (Controller Anti-Lock Brakes) device being the issue, but found out it would throw a code if it was malfunctioning.

 

If it isn't throwing a code that doesn't mean its not malfunctioning - trust me.

I've had backfire problems with no codes and changed a bunch of stuff before I found out an O2 sensor was the culprit.

My tranny would not downshift and there was no codes.. turned out to be a relay.

Just trying to make sure you dont overlook anything.

 

sxrsil3nt is correct

No codes showing means nothing you still need to check things out.

 

Thanks for the suggestion. I changed the Differential fluid out and check all the gears for wear. Everything looked great. I did have the typical small amount of metal flakes on the magnet, but the fluid looked surprisingly good. I drove the truck three different times trying to get the rear brakes to lock and couldn't. I tried hard and soft braking at high and low speeds and everything
worked fine for now. Only driving time will tell if this was the true cause.

 

That would be nice

Only time will tell

I just had my brakes chide on me yesterday the ABS started pulsing on a bumpy braking condition you could hear the valve open and close rapidly not sure why that happened other than I was braking on a very bumpy spot in the road.

I guess the ABS was confused as to what was happening

 

Just a follow-up to my my issues. Since changing differential fluid everything seems to be working properly. I have been unable to get the rear brakes to lock-up.
I have also discovered my scanner will no longer connect to my PCM. I'm starting to wonder if my brake issues and rough idle issues might be related to a PCM going bad.
The PCM plug C2 white and orange wire reads the vehicle speed sensor. I tried a second scanner and get the same fault error. Scanner is unable to connect to PCM.

 

Have you taken a super bright flashlight and looked inside were it plugs in it may have some corroded connections check out the backside of them also.

Trace the wires inside the cab someone may have spliced into a wire or two why? Who knows