Alright so I have a 1978 f100 2WD that had manual brakes, the master cylinder went bad so I decided to change the whole system over to power. Went to the junk yard and took everything from a 1979 2wd, the brake/clutch assembly as well as the master cylinder and brake booster. After some negotiating I got the power parts installed. Guess what, no pedal return.
The brakes have been bled and I've now purchased a new master cylinder, my next move is to snag a new brake booster, (so much for junk yard savings). But i'm not necessarily inclined to do so until I know that will solve the problem. Last thing the engine is poor and needs to come out, thinking that it might not be making enought vaccuum. But hey it still does 55, just screams like its got a bag of tin cans stuck in the fan. I love this truck and need to be able to drive it, any help is welcome.
Brent p.s. anyone in the portland or area with a 302 let me know

 

Did you in fact use everything from the '79 donor truck?
There is something different about the '79 as I recall.
I got a replacement booster setup years ago from a junkyard for my '78 F150 2wd and as I remember I had a real bad time getting it to work.
You should make sure you got everything from the donor from the m/c to the pedal including the firewall brackets, and install all this onto your truck.
How about the vacuum to the booster?? how about the check valve @ the booster?? I'd replace IT before you get anouther booster.
Hope some of this helps!