What brake booster?!

[creed1969]

The last few weeks I've been digging around online trying desperately to figure out what brake booster I need to buy: Delco or Bendix. I've read many threads on this forum but still haven't come up with a solid answer.

First of all, this is a power disc brake install on my '69 C10 that was manual drums before. So it's not as simple as checking to see if my old booster is "gold" or "black"...I don't have an old booster .

I bought my master cyl. from LMC a couple years ago actually, and it is listed in their catalog as the only "power" M.C. for 71-72 halftons. The pushrod hole depth is 1-5/8", and the bolt holes are 3-3/8" on center. Here's a picture of it:
[IMG][/IMG]

I have a booster bracket from a '72 chev halfton that I'm planning to use. I don't know what booster the '72 had. The square bolt pattern where the bracket bolts to the booster measures 3-1/2" vertical, 3-1/4" horizontal.
[IMG][/IMG]

From what I've read, the Delco boosters were most common on the 71-72 halftons. Can anyone tell me if a Delco booster will fit my master cyl. and/or my booster bracket? I'd sure appreciate it.

[RHGuyettejr]

My 71 had a black booster and that same square bolt setup. I have a new booster, but never tried to install it so I don't know if it would have been the same as I ordered it through parts plus. I can measure the bolt pattern if you want, but I have sold the truck, and just saved the brake parts to upgrade my 69.

[creed1969]

Thanks for the reply RHGuyettejr, yes if you get a chance to measure the bolt pattern on the back of your booster that would tell me whether or not a Bendix booster will fit my brackets. (apparently the Bendix boosters were black).

[RHGuyettejr]

Yep sounds good, The measurements going side to side on the studs that mate to the bracket are 3 & 3/4" center to center, going up and down they are 3 & 1/2" center to center, and on the side that the MC bolts to the studs are 3 & 3/8" center to center. Hope that helps. Also here is a pic of the booster in the other truck I had that the new one was going to replace.

[creed1969]

Awesome thanks, that's helpful! Was your '71 a 3/4 ton? Looks like it had a dual diaphragm booster, and the brake lines hook to the prop. valve opposite of a 1/2 ton. I think...

Does your booster have the Bendix name stamped in it? Just hoping to confirm that's what it is.

[creed1969]

oh wait...just noticed your booster's horizontal measurement is 3-3/4" while my brackets are 3-1/4". I overlooked that at first. Maybe I need a Delco booster afterall...

Does anyone know if the Delco booster would have a different bolt pattern?

[RHGuyettejr]

Yeah it was a k20. The new booster says delco on it, and it is a refurb.

[creed1969]

So I've confirmed that a 3/4 ton Delco brake booster won't fit my brackets (thanks RHGuyettejr). However, I'm still unsure about the 1/2 ton boosters. Can I buy either a Bendix or a Delco as long as it's for a half ton?

I know there's someone out there that's figured this out. I don't want to have to start buying boosters and trying them for fit . They don't have them in stock here, and have to order in.

Can anybody shed some light on this for me?