WA WTT 3/4 ton booster for 1/2 ton

[69SCSS]

I have a 3/4 ton booster on my truck, and my master hits the alternator. I need a 1/2 ton booster which is a bit shorter than the 3/4 ton to make it all fit. I just had the booster blasted, and painted it. I'd like to find one in the same condition, if anyone wants to trade. I only need the booster, not the brackets. Below is what I have and what I need, you can tell they're quite a bit different in length.

Thanks!

[w314speed]

I have changed many 1/2 ton to 3/4 ton booster, as they are far superior.

I think you have they wrong style master cylinder that is two long.

The pics are of a NOS MC which is 8" from mounting surface to front.

My 72 BB has 1" of clearance at the alternator.

Hope this info helps! Thanks, Dan

[69SCSS]

The master clears just barely, but the brake line for the rears hits the alternator. It's just the way the Inline tube conversion is set up. The master I have isn't that long, I'll have to measure but I doubt it's much longer than yours. I may just bite the bullet and grab a new delco one from Autozone if no one wants to swap. Gotta have brakes right?

[Livrat]

Unfortunately its not as easy as just changing the booster as the 1/2 ton booster uses a different master cylinder and brackets than the 3/4 ton.

In fact if you pull your master cylinder off of your current booster I suspect you may find your master cylinder has the recessed hole in the piston and the rod in your booster will not reach.

Here is a write up I did a few years ago that may help you out a bit.

http://67-72chevytrucks.com/vboard/s...d.php?t=214559

[69SCSS]

Originally Posted by Livrat

Unfortunately its not as easy as just changing the booster as the 1/2 ton booster uses a different master cylinder and brackets than the 3/4 ton.

In fact if you pull your master cylinder off of your current booster I suspect you may find your master cylinder has the recessed hole in the piston and the rod in your booster will not reach.

Here is a write up I did a few years ago that may help you out a bit.

http://67-72chevytrucks.com/vboard/s...d.php?t=214559

Well that's interesting then... because the master is for a 1/2 ton (just double checked the part # to make sure), so it may not work anyway... interesting... maybe it'll work with the right booster. Thanks for the info!

[Livrat]

If your master cylinder is for 1/2 ton it definitely will not work with your booster.

You will need a booster AND brackets off any 67-72 1/2 ton.

Or if you would like to upgrade to a little better stopping power, get a dual diaphram booster and brackets off of a 67-70 3/4 ton like the one pictured on my wife's Blazer.

(the booster you have is off of a 71-72 disc brake 3/4 ton and is different from the 67-70 3/4 ton drum brake system)

[69SCSS]

Originally Posted by Livrat

If your master cylinder is for 1/2 ton it definitely will not work with your booster.

You will need a booster AND brackets off any 67-72 1/2 ton.

Or if you would like to upgrade to a little better stopping power, get a dual diaphram booster and brackets off of a 67-70 3/4 ton like the one pictured on my wife's Blazer.

(the booster you have is off of a 71-71 disc brake 3/4 ton and is different from the 67-70 3/4 ton drum brake system)

Yep. I have a disc brake swap (this booster was taken off a '71 C10) and I didn't have a booster / master when I got the cab, so it's all from piecing things together as I go. This has lead to me getting a lot of the wrong parts... LOL! Seems like I'll be visiting some websites for a booster kit... should have just got the full kit in the first place! Someday I'll learn.

OK... anyone happen to have the correct booster / brackets for sale?