Pretty close I think.

 

Bleed all the old fluid out and nothing has changed. If the RABS sensor is bad will it cause the pedal to fall half way before any braking power if the rear brakes are adjusted correctly?

 

yes. that is the reason for blocking off the rear circuit. if pedal gets firm, then hook the rear circuit up and try bypassing the RABS. if it stays firm you know it is the RABS valve.

 

Is the Rab's located on the rear diff?

 

It's located inside the driver side frame rail right behind the motor

 

The valve or Senors is in the frame?

 

The RABS SENSOR is the VSS, which is in the rear diff.
The RABS VALVE is on the rear hydraulic line, in the frame rail as described above.

 

Sorry. I was thinking about the valve.

 

I replace the rabs on my way to class will no change in the braking. I did manage to find a parking lot to feel out the brake a little better and it seams as if I have no back brake but the fronts are all that are stopping me. Is it safe to assume that it is the valve? Is there any way to bypass it permently?

 

remove the line going into and out of the valve, get a small piece of brake line and connect the two together.
if the brakes work the problem is in the RABS valve.

 

I finally got time to pull the line and plug it as suggested and the brakes got rock solid. I am assuming the ads valve is toast. Would it be better to bypass it or replace it?

 

Buler? Buler?

 

https://www.ford-trucks.com/forums/6...ml#post5918294

I know there is another thread, can't find it. Besides, I don't know who Buler is but he took the day off!

 

I don't know precisely how much my brake pedal goes down, but it has some travel before it stops the truck, maybe even half way. Is there a standard amout of travel for the brake pedal?

 

More about Zero Loss Booster...
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https://www.ford-trucks.com/forums/6...-problems.html