I've been reading a lot of threads here regarding the fading brakes issue and the fix for it by installing a zero loss booster. I also have the Ford part # for it. What I have not been able to find is if this problem and the fix is only for Diesel trucks, or gas trucks also. Seems all the refferences I've come across are from Diesel trucks. I have a 1993 with a 460 and have the fading pedal.
Just want to make sure before I start on the brakes. I have not yet checked out any of the brake related components. I towed the truck home a few months ago and rebuilt the engine. My first rebuilt, did the first start a couple of days ago and everything went fine. Drove it around the block and found the fading pedal.

The truck seemed to stop fine, but like I said it was only a 5-10 MPH drive and lasted a few minutes. The only thing I checked is that the pedal felt equally mushy with the booster connected and than disconnected. And although the truck does stop from slow speeds, the pedal goes to the floor and has to be pumped to regain some pressure.

Thanks

 

Sounds more like a fluid issue, are there any external leaks? If anything has been opened up there will be air in the lines, and will need bleeding, the rear shoes might need adjusting, or the master cylinder may be bypassing internally.

If it were only the booster the pedal would just be hard, and you would have to "stand" on the pedal to stop, but the pedal would not be mushy or go to the floor.

 

Thanks,
This gives me a starting point.

 

I deal with stuff like this on a daily basis. If you run into a dead end send me a pm and I'll give you my number. I can walk you through what to check and look for.

 

I appreciate that very much.
I will start looking through it and post back with what I found and what did, or did not help the situation.

Thanks.

 

I wanted to update this thread since this is a common issue.

Seems the fading pedal was caused by several worn components.
I have replaced almost the entire brake system including rear pads and cylinders, all new rubber lines, new front calipers and shoes and new rotors. I also replaced the master cylinder, but I don't know if this was a problem or not. This was the starting point.
Everything was worn and leaking.

I drove it and it still had the fading pedal. I then kept adjusting the rear drums until the fade went away. The only thing I did not replace was the booster and as it turns out, if I had it wouldn't have helped anyway and a waste of money.