I have a 1994 1500 2wd that all 4 brakes started dragging. I've replaced the Master Cylinder and checked the lines and calibers but its got me scratching my head..Brakes are good but when you put it in neutral it doesnt want to roll. tried looking up the combination valve and cant find anything on it...any ideas??

 

You sure that all 4 brakes are dragging? Dragging parking brake, on a one wheel, is enough to keep vehicle not rolling.
Does any of them get warm or hot after driving?

 

Jack it up, spin the tires by hand. See how they feel. Now, step on the brake hard once, and spin the tires again. Feel any different?

 

Yeah unfortunately all 4 are dragging I drove 2 miles from home and smelled burned brakes and noticed a drag when i let off the accelerator. Got home and all 4 wheels were hot. I replaced the master cylinder thinking that maybe they werent getting the proper amount of fluid but still have the drag i havent driven it but around the block since

 

Is the master cylinder push rod adjustable? If so, It might be adjusted too long so the brakes are always applied. Could also be the pedal. Something could be bent or interfering with it moving up all the way after being pressed.

 

Tried to spin the wheels and the front passenger one wont budge

 

Crack open the bleeder. If it now turns, replace BOTH front soft lines.

 

Check the brake booster if you don't find anything else. Remove the vacuum hose from the booster and plug. Take a spin and see how the brakes feel.

 

Keeping in mind that without the vacuum boost, you will have to step HARD on the brakes to get much action out of 'em.

 

When the flexible brake hoses are old they will deteriorate on the inside. Then they can work like a check valve and prevent the brake fluid from releasing out of the brake cylinder.