More on disc upgrade

[F100builder]

Hey Keith. You're right. I had pretty much gathered all of the information through this great website and community of bump owners! Your pictures and tech pages are a jackpot of good stuff! Now, I've only had my bump since December and I'm certainly no expert but I feel like I've known these trucks forever due to this website and several salvage yard visits! Thanks for the great info and website Keith!

[mrtleavitt]

Hey guys, mind if I butt in? There's one thing I'm unsure about with reading this thread and the "Disc Brake Conversion" instructions. I have a '69 F100 running gear with a '72 cab, I'm putting on disc brakes from a '75 F150. Can I use my booster and master cylinder from the '72 or do I have to go with the '75 booster and master cylinder? Or can I go with the '72 booster and a '75 mastercylinder?

[F100builder]

Hey mrtleavitt. My answer to all of your questions is yes (I think!). From what I've learned so far, you should be able to use your '72 booster/MC with the '75 discs but I'm thinking you will still need the proportioning valve from the '75 as most '72 F100's were all drum (72 F250's and bigger had disc). Unless.....the ratio is the same; all drum vs. drum/disc. Anyone know?

BTW, I bought your rear sport bumper brackets off of ebay! I can't wait to get them on the truck!

[MustangSteve]

Drum/Drum has only a differential pressure valve to turn on the warning light and limit flow to the rears if a leak is detected. There is no proportioning valve function, except with the disc/drum setup.

[Banjo]

I thought my kingpins went in too easy too upon reassy, but machine shop said you should be able to just lightly tap them in if lubed up well. I used antiseize on mine and tapped them home with a brass drift (no hammer) and mild pressure. Still seemed to light to me, but he said he'd done kingpins before.

[mrtleavitt]

Ya, I have the proportioning valve from the '75 and I know I have to use it. So I can use the '72 booster with the '75 master cylinder? Do they bolt up to each other?