I have a '04 f250 SD with a 6.0l diesel. I have replaced the entire braking system with the exception of the ABS pump. I STILL HAVE a soft pedal that sinks to the floor before stopping. My question is...Is there a conversion kit to install a vacuum boost pump in place of the hydro boost pump?

 

Have you got codes? Having worked with both systems on this platform at the design level, I'd stick to the hydroboost, which provides a higher pressure under panic stops, and look more into what you are doing wrong or not doing. Aftermarket master cylinders suck, can be bad out of the box, and you'll never get a good pedal if you've fully bled down and get air in the ABS. You'd have to use a computer to activate the ABS and clear the valves and accumulator.

Also, the ABS controller can have an inner valve fault. If you have the ABS controller that's down under the driver's battery, it's an easy test.

A quick test to see if the master cylinder is good is a fast, hard push. If it stays high with that, the master cylinder is at fault. It even calls that out in the ABS note. The hydroboost will not ever cause a long pedal.