Well after the wife deciding that we were not going to spend the summer holidays with her parents, and that the camper had to go, and that we had to buy a fifth wheel, I finally get around to getting the truck ready.
It is a 77 F-250 supercab, 2wd auto, heavy duty brakes, 400CI
We only use it about six months a year, for holiday time and such, so it does sit outside on ashphalt and unfortunetly the driveway floods pretty good, so the water is hard on the truck, anyway I fire it up after putting the batteries in it, that I keep in the garage on charge.

And I drive it up and down the driveway, well the brake line to the back blows behind the fuel tank, okay so I get under there and see that the driveline is pushing right into the tranny, so now I have to do the steady bearing on the two piece driveshaft.
So I take it out and it has to be hammered to seperate both splines, then I take down the fuel tank and get at the brake line and fix it, now I have the line in and brakes bled, replace center bearing, all three u-joints, and the rear tranny seal just to be on the safe side and the splines are tight going together even though I lubriplated them and then I go to move the truck and it is sluggish, so I realise the brake lights are on, so I pull up the pedal and lights go off and truck moves quicker, so put brakes on again and sure enough truck doesn't really want to move till pedal is pulled up to make it move and take the rear lights off.
So my thought is that the master cylinder that is not that old must have buggered up from not getting used.
It has heavy duty drum breaks in back and dual piston calipers in the front, but the only way I can see the brakes hanging up is the master cylinder as lifting the pedal seems to release them.
Any other ideas? Or have I hit on the reason for the problem?

 

I had a long bed 78 a while back that was doing the same thing and I took
a can of PB blaster and spray the linkage behind the booster and it seemed
to fix it for a few months, but this truck was sitting a lot also, and I sill ended
up having to change the master cylinder, after a while!

 

My 79 sits a lot and I had the same problem.I lubed the linkage behind the master cyl.

 

I had the same problem with the pedal returning on my 79 F250 4X4. I put a master cylinder on, nothing. I lubed the linkage, nothing. I put a new power booster on and bingo, brake pedal returns with no problem and have excellent stopping power.

This truck sat in a field for more than 4 years, so I can understand why booster was bad.

 

Excact same problem with mine.Replace the booster works great now.

 

Thanks for the advice, I actually had not thought to test the booster, if I recall, the way to check it is to have your foot on the brake pedal and start the engine and you should feel the pedal drop a bit.
So hopefully I will try that and see if I am right.

 

Well it is my back brakes hanging up I found out, I looked at the proportioning valve and the little tit is not sticking out at all, I could not get a hold of it or anything.
Borrowed a guys pressure bleeder and flushed the whole system and got lots of dirty fluid and stuff out, but I think I will have to take the piece out of the valve that is supposed to stick out and see if I can fix it.
I am hoping that is the problem.
What do you all think?

 

How about replacing the wheel cylinder's.
Up here they are only $10.00 each for new one ?

Also consider buying a new hold down kit for both sides.
It includes New return springs

 

its the booster