My toad rear brakes wear out

Agree on the emergency brake not fully disengaging as the likely cause.

Well, our 2004.5 Chevy 2500HD Dmax diesel CC LB 4X4 truck ordered new in 2004 which has only been used for RV towing/hauling still has the OEM rear brakes still on at getting close to 200,000 miles on them. Front brake pads were changed at about 126,000 miles. You have something seriously wrong with your truck/rear brakes if only getting 5000 miles on a set of rear brakes if they are decent quality. They must be dragging almost constantly. Nope, not normal at all!

Emergency brake binding and not fully releasing?

I'd say you have your braking system set way too high. What happens at low speed on a loose gravel road when you apply the brakes, do the rear tires lock up and drag?

Bill