I just purchased a 1965 f250 custom cab. The truck is modified with a 390 motor, march pulley system, intage air, etcetcetc.... my question is concerning the brakes. It has had a 4 wheel disc brake conversion, only the rears and the fronts are off of diffrent vehicles. The fronts i believe are off a 75 or so f250. They are the single piston calipers... When i purchased the truck the front drivers side caliper was locked up.. after figuring out what i was working with I replaced the caliper and brake pads on that side in order to get the vehicle home. Everything matched great. However i noticed that the pads are shorter than the piston in the calipers meaning when i look at it all bolted up i can see an inch or so of the top of the piston past where the top of the pad sits?

Firstly is this normal for this set up?
And secondly i have a very odd groan from the brakes up front...almost like something in dragging or binding up slightly.. It vibrates the truck but goes away if you apply mor presure to the pedal...??

Also can or will the dual piston set up bolt onto the factory set up for a single piston caliper? I though maybe the guy before me put the wrong calipers on the front conversion?

any help would be of great assistance

thank you so much

 

sounds like you may have the wrong pads and need new discs/rotors- post a pic

 

I have the dual piston calipers and I don't think there's any resemblance to single piston calipers. I also have ginormous rear drums from a SWD 1-ton and the master cylinder/booster from a '76 1-ton and new brakes hoses for the same. The brakes are phenomenal. It's right up there with my '12 F250. They may fade under hard braking, I don't know, but they will stop on a dime and give some change back.

I also know that for dual piston trucks there was a change in calipers at serial #XXXXX and up. Perhaps you are running into similar?

 

Dual piston caliper disc brakes: Optional 1968/72 F250 2WD & F350.

Single piston caliper disc brakes: Standard equipment 1973/79 F250 2WD with 6,100 & 6,300 lbs. GVWR's.

Dual piston caliper disc brakes: Standard equipment 1973/79 F250 2WD with 6,900, 7,500 & 8,100 lbs. GVWR's.

1973/79 F250 2WD with single piston calipers use the same disc brake pads, calipers and caliper pistons as 1973/79 F100 2WD; 1975/79 F150 2WD & 1975/79 E100/150.

GVWR stamped on the 3rd line-far left of the Warranty Plate, riveted to the left door face below the latch.