Which booster is right for my F250 w/disc (8,100lb GVW)?

[robroy]

Hi! I've spent some time browsing through the 1972 shop manual and believe I've found the root of all the confusion. The shop manual doesn't say which booster should go on the F250 with disc brakes!

It covers two boosters for our trucks: a single diaphragm and a tandem diaphragm unit. Just like you'd guess, the tandem diaphragm is the larger unit.

As you can see in this scan, the single diaphragm unit applies to the "F-100 - 350 and P-350 - 400 with Drum Brakes." The question here is: does the "Drum Brakes" part of the application apply only to the P-350 - 400, or ALSO to the F-100 - 350. I'm guessing that it applies to both of them, which means this booster is for trucks with drum brakes only.



And here's the single diaphragm booster:



Now here's the application information for the tandem diaphragm booster; it says that it applies to "F-350 with Disc Brakes." The question here is: does this also apply to the F250 with disc brakes, or is this TRULY only for the F-350?



And here's a photo of the larger, tandem booster.



Thus, according to the 1972 shop manual neither of these boosters applies to the F250 with disc brakes! Or am I missing something?

Thanks for all the great advice folks!
-Robroy

[fordman]

disc and drum brakes use the same booster. it is the master that makes the difference. the dual vs the single is because of engine placement in the truck. the 460 had a hard time using the larger booster because it hit the valve cover.

[robroy]

Hey Fordman! Thanks for your reply.

I'm not 100% clear on what you mean about engine placement differences; both of these boosters, according to the shop manual, were used in 1972 (before the 460 was around in trucks).

Do you mean to say that the engine placement is somehow different in the 1972 F-350?

Thanks!
-Robroy

[fordman]

i could have sworn that i worded that differently last night. the larger booster. in some trucks would hit a 460 when it was installed in them. so they had to change to the smaller booster so the booster wouldn't hit the valve cover. it was just something i heard about. i've never ran into that probelm before myself.

[robroy]

Hey Fordman, thanks for the clarification!

Anybody else willing to comment on this booster application dilemma?

Thanks!
-Robroy

[robroy]

I decided to go with the big booster. Here it is freshly painted with Rust Bullet and mounted on my firewall:



Robroy

[robroy]

Good morning!

Now that I've driven the truck with this booster installed, I wanted to report back.

The booster's performance is superb, and the brakes feel better than they ever did before. I'm not sure how much of this is due to the new booster, and how much is due to everything else being new at the same time! But at least this booster seems to work wonderfully.

There's one thing I've noted that I wanted to warn people about though. This large booster sticks out several more inches than the more common, shorter booster, and that interferes with the tank-style windshield washer bucket mounted on the inner fender! So if y'all choose this larger booster, be prepared to either use the sack-style fluid container, or to move the mount location of the tank-style container forward several inches.

Robroy

[fordman]

i have the same problem with my 4wd. the brake lines were bent by me. and they were bent out too wide of a circle. and they hit the washer tank. so my tank doesnt like sitting there correctly. the lins push against it.