Rear Brakes Dragging

[EHein]

I am pulling a 14,000 lb fifth wheel trailer with Max Brake Controller on truck.

A couple of days ago I noticed that my brakes were dragging a little bit. I

checked my Max Brake Controller and it was showing 2 bars when foot was off

the brake pedal. I unhooked trailer, recalibrated brake controller. Took pickup for a drive (without trailer) and noticed rear brakes on pickup were dragging. Jacked up rear end. When you step on brake pedal and release, it takes a minute or so for the rear wheels to release. Had wife step on brake pedal and I opened the rear passenger side bleeder screw and brakes released instantly.



The question I have is this my master cylinder acting up? Or, could it be calipers? But both rear wheels are doing the same thing.





2003 2500 QC SB 48RE basically stock



EHein

 

[B.G. Smith]

If the brakes relaease when you open the bleed I would say the calipers are ok. bg

 

[JBallou]

Brake hoses, or hose in the case of the rear brakes. The one you need to replace is the one that goes from the frame down to the axle. Should be the cheapest and most likely of all of the components that is causing the problem.



Might as well do a drain and refill of the brake fluid system. Suction out the master cylinder and refill with fresh. Then open one bleeder at a time for a while to drain out the old fluid.

 

[jhenderson]

Try removing the power steering res. cap. If the vent is not working it will put a slight amount of pressure on the brakes through the hyd system. You will know this by the pop when you take off the cap.

 

[SDrake]

Nothing in the rear will affect the Max Brake. I assume you have the max Brake pressure sensor at the master cylinder. The fact that Max brake is seing pressure there simultaneous with the rear brake on the truck says that the master cylinder or what ever actuates it is not releasing the pressure when you take the foot off the pedal. A hose in the rear could cause the rear brake to stick but it would not affact the maxbrake. I would be looking at the master cylinder or brake pedal linkage or the boost setup.