What you are describing is probably caused by bad brake fluid. When I say bad I mean you probably overheated the brakes to the point of boiling your brake fluid.. (like you were thinking) Once you boil the brake fluid you get moisture in the system and the only way you will get rid of it is to do exactly what you are thinking, flush the brake fluid!
FYI, this is true of your truck also.. If you are experiencing brake fade or pedal pressure problems, DO THIS!!! You will not be sorry.. If you can't do it yourself, pay someone to do it, It will be the best money you ever spend.
And as for what Warlock said about tossing your e-brake, I couldn't agree more! To make it work decent at all, you have to re-clock the arm or adjust it till you have a slight bit of drag..
I tossed mine and installed a "park-lok"
Pro's - It works awesome, Put your foot on the brakes, hit the park-lok and your vehicle WILL actually hold..
Con's - It works via hydraulics, so if you had a fluid leak and your brakes fail, so will it. But hey that POS stocker e-brake isn't going to save you anyway!
Hang tight and you will be able to buy the rear disc brake set-up from a XTZ (4 wheel disc) and believe me it works WAAAY better!
XTZ 1000 Motor Swap : MB Cage : Aluminum Roof : Jones Fab Wing and Sheet Metal : Rattle Snakes w/OMF Beadlocks : Morphic Acuated Light bar : 6 4" Fuegos : 8" Lowered Beard Seats : K&R Performance Air Arm : Aluminum Radiator : CVT Blower : PLX Wide Band : Lowrance Baja 450c : Diecast Playcars Long Travel : Driveline Alternator : 4 Wheel Disc Brakes : 3.1 Gears : Full Bore Rear Fenders : Dual HID Head Lights : Horn Blasters Air Horns : Simpson 5 Point Harness : Trick Performance V Gauge :