69 f250 problem with brakes

[69fordtruck]

Hi everyone im new here. Glad to be a member. I hope I can get the help I need to fix my problem. ok I have a 69 f250 that had a disc brake swap. the master cylinder and booster were still the drum brake ones and the proportioning valve was also not installed. well my brakes actually worked great but my power booster was leaking so I replaced it with a new one and master cylinder and this is where my problems start. I put a new master cylinder and booster and make brakes will not work properly now. so I replaced the drum master cylinder with a disc brake one and it did not change . my symptoms are that when you press the pedal its soft about 3/4 of the way then its hard and you have to real press on it to get the brakes to work. any ideas what can cause this? the new power booster I put on I noticed wasn't as big as the one I took off. im thinking the power booster is the problem. im wondering if a 1973 f250 brake booster will work on my 69? any and all help is appreciated thank you

[Mach428]

Wow, where do I start. I'm confused as to what you had and what you now have.

Okay, if the master cylinder was never changed from drum to disc, the brakes were not working as good as they should. The disc caliper requires more fluid than wheel cylinders. That said, it appears that the brakes DID work before you changed the MC and booster and now they don't.

Did you thoroughly bench bleed the master cylinder? Afterward, did you thoroughly bleed all of the brakes? Also, do you have the correct proportioning valve on there now?

Your brakes will never work properly unless you have the right equipment and bled.

[carnuck]

Sounds like the new master may be bad or the rod fell out between them (no fluid would happen)

[69fordtruck]

Ive been researching and found out that the booster i bought is for the drum brakes and is tje reason why its smaller than the one i took off. The disc brakes tale a different booster and is bigger like the one i took off and replaced. The boosters even specify for disc brakes with single or dual piston calipers. Theres a different one for single and a different one for dual piston calipers. Now the problem is the boosters ive found dont have the adjustable rod. Will it still work? Also do you think the booster is the problem?

[carnuck]

If you have the old master/booster, measure the rod stickout new vs old and the depth of both inputs..

[69fordtruck]

Thanks for the help. I swapped out the booster with a 1 ton booster and it fixed the problem.