Brake booster/master question 3/4 to 1/2??

[Furno68C20]

I have a 67 1/2 ton that has manual brakes. The master cylinder is filled with debris and no fluid since its been sitting for a number of years. This truck is Drum/drum

I have a 68 3/4 ton that i just put disc conversion on, it was previously Drum/drum with power breaks. This master and booster is in good working condition.

My question is can i put 3/4 power brake set on the 1/2? I see that the booster extends the master cyl / distribution valve brake line ports forward. What would be the best solution here..new lines? just extend the lines? any size difference in brake lines?

here are a few pictures.

1/2 ton on the left 3/4 ton right.

What is that rubber washer? does that go between the master and booster?

sorry about the side way picture.

Thanks in advance!

[Sheepdip]

The rubber washer is the end seal for the booster that is held in by the master cylinder, it goes on the push rod just like you've got it in pic 3.

Install the push rod, slide the rubber washer on and seat it in the end of the booster, then bolt the master up.

The push rod will have a little adjustment screw on the end that goes into the master, there should be about a 1/32 to 1/16 gap before it makes contact with the master piston. You can check it with contact grease/putty to assure you're gap is correct.

[Furno68C20]

Ok thank you. anyone else??

[notsolo]

This is a common upgrade, I put a bigger booster and MC...on my 72....works fine.