2001 dodge dakota 4x4. replaced new brake line to rear. when pumping the brakes and bleeding manually fluid flows good. truck off the brake pedal is hard. once the truck is turned on and running the pedal goes to the floor. replaced master and still having this problem even after pressure bleeding and manual bleeding. front bleed ok both ways. fluid will not come out of rear brakes with pressure or gravity bleeding. any suggestions?

 

Combination valve is blocking the rear circuit. (brake lite in dash on?)

Grab a friend, pump up the brakes, and HOLD the pressure. Crack open one of the FRONT brakes. Do that a couple times, then pump the brakes till you get good pedal. See if the lite has gone off.

Going to move this to the 2nd gen Dakota forum for you as well.

Welcome to DF!

 

Make sure you have the correct master as the Dakota has 4 or 5 different ones if I remember correctly.

If correct then you may have clogged up rear lines to the cylinders pull off the rear drums and hardware and inspect the cylinders.

When I did my rear brakes both cylinders were frozen and the brake lines were full of black thick muck.

 

^ that

 

Husband is having the same problem. Replaced both rear cylinders and there is still no peddle.

Posting own thread....

 

I just went through this on my 1988 Dakota - the rear cylinders were plugged up solid.

New master cylinder and booster, new rear wheel cylinders, (actually all from backing plate save for the parking brake parts new), and a full bleed of the system with my vacuum bleeder and the truck now stops on a dime and gives ... well, about 3 cents change *grins* It used to demand an extra quarter, though, so THAT'S better.

RwP