I can get the system to bleed when the truck is off with. It has solid pedal pressure. As soon as the truck starts I lose all pedal pressure and it goes to the floor. No brakes whatsoever. Also, no leaks that I can spot anywhere. I've asked around to a few folks and it sounds like my issue could be the brake booster. I've found a couple options around the web. Do I need an adjustable pushrod? I'd also be open to any options that I could pick up used.

 

If the basic hydraulic system is in order, the booster will not allow the pedal to go to the floor no matter how defective it might be.

 

I'm not actually sure if it literally goes to the floor. I was just saying that it goes from having pedal pressure to nothing.

 

That kind of sounds like how the pedal acted in my '96 ranger when the booster developed a leak in it.

 

I'm pretty sure what MPH is saying, If your hydrolic system is right its not the booster. The booster aids in the ease of pushing the pedal. Sounds like a bad M/C or bad distribution block.

 

This is a new M/C from Rock Auto that I bought a couple years ago. It was the cheapest one on the list... I can pick up another one and give it a shot. Any thoughts on how I can check the distribution block? Is there another name for that? i don't see it on Rock Auto.

 

 

Brake system, Tires, and Seatbelts. They all involve stopping. USE THE GOOD STUFF!

 

So I ordered a brand new Master Cylinder. I've read that pushing the pedal down too far during bleeding can ruin a M/C and I did have my wife on the pedal pumping away. I think I'll put a block of wood behind the pedal next time, just to be safe.