brake booster update

[76bonanza]

A few weeks ago realized my brake booster was leaking? Did a little reseach I had a bendex booster on it so I order the 1/2 ton booster from a 71 bendex style. Got it then found out it was smaller then the one I had. I had the booster from a 3/4 on there. So I thought what the hell and threw it in there drove for about one week hated it hard to stop always creeping at stop lights. So I took it back got the 3/4 ton bedex for it. Holly crap anyone who is running drum drum with a 1/2 ton single diapghram booster please go out and buy one for the 3/4 and change it out. I dont event think I will mess with disk brakes now. Stops on a dime (compared to the single 1/2 booster)

Anyway thanks for everyones help.

[krue]

Cool. I still have a 3/4 booster I can throw back on mine.

[76bonanza]

Krue it threw me thru the windshield first stop I made. On a side note the one for the 3/4 had a short MC push rod it was also not adjustable.

[tnblazerk5]

i used a 3/4 ton master cyd and booster(all of a 78 truck) on my 67 when i went to disk front brakes , and yea all ya got to do is think about touching the brake pettel and it stops

[Robert1970C20rstbukt]

If you think the 3/4 ton booster is good you should get one from a 1 ton truck, it makes a BIG difference.

[Sweet72]

I went from manual brakes to a 3/4 ton vacuum booster and was amazed at the incredible stopping power on my short bed 1/2 ton. The manual brakes would barely hold the truck back at a light (auto trans.) and aren't safe in today's traffic, too many foolishly over confident drivers in SUVs and imports.

tnblazerk5, I like your avatar, that about says it all! The new plastic trucks will look tough for a few years 'till all that crap starts falling off, turning to mush from UV's and warping.

[PICKMUP]

The big dual diaphram 3/4T PB system (71-2 DB) uses a unique/different MC rod and brackets and MC. I always use the complete package, incl prop valve so everything is sure to work together in a 1/2T.
You can get into trouble mixing up parts from different brake systems, like brakes that drag or don't apply all the way.

[70GMCer]

That has answered my question before I even asked it. I was going to start a thread asking about the difference in stopping power between the two. I was thinking on removing my 3/4T mc for the 1/2T because the way the 3/4T sticks further out in the engine bay than the 1/2T one. I wanted it closer to the firewall, but I don't want to sacrifice stopping power. Guess I'll just leave it alone now.

[roadking]

i have the 3/4 ton booster on my 1/2 ton, only problem i have is the stock wire for your brake warning light will not reach the MC because of the wider power booster, but does stop great now. also the stabalizing bracket on bottom from the MC to the firewall is a little longer for the 3/4 ton booster, you will have to change that out if you currently have a 1/2 ton booster stabalizing bracket.

[76bonanza]

robert 1970 the 3/4 and 1 ton use the same booster. Also if you have drum/drum make sure if you use the prop valve out of a donor it is also a drum/drum. As far as the pushrod just keep your old one and use it in the new booster if you have to. The 3/4 ton uses a shallow port M/C the 1/2 uses a deep port MC. Dont want to mix the push rods up or your pedal will be to low.

[Robert1970C20rstbukt]

My truck has the original front and rear drum brake system. The booster I took off the truck was smaller than the 1 ton booster. The original? one was only a single diaphragm and was thinner and bigger around, the one I used from the 1 ton truck was a dual diaphragm booster and was longer and a smaller diameter. If the 3/4 and 1 tons are the same then somebody put a 1/2 ton booster on my truck. Anyway the 1 ton was a 69 so the master cylinder and pushrods were the same.

[76bonanza]

the 3/4 ton from the 71 is dual and the part number for the 1 ton is the same for 71 any other year I can not speak of as I have not looked into it. I do know that the 71-72 is different but not sure how from the previous years.

[Olden Days]

Originally Posted by Robert1970C20rstbukt

My truck has the original front and rear drum brake system. The booster I took off the truck was smaller than the 1 ton booster. The original? one was only a single diaphragm and was thinner and bigger around, the one I used from the 1 ton truck was a dual diaphragm booster and was longer and a smaller diameter. If the 3/4 and 1 tons are the same then somebody put a 1/2 ton booster on my truck. Anyway the 1 ton was a 69 so the master cylinder and pushrods were the same.

I have that same samller diameter and longer booster on my 70 C30 Robert. I have not looked at other C30's but I have never seen one on a 3/4 ton that looks like mine

[Bob B.]

Just curious, when you talk of the push rod, are you talking about the rod out the back of the booster, or the long rod that goes from the pedal to the linkage? It seems that most of the pedal rods are adjustable. Thanks.

[krue]

I think he's talking about the rod between the booster and the master cylinder.

[Robert1970C20rstbukt]

Originally Posted by Olden Days

I have that same samller diameter and longer booster on my 70 C30 Robert. I have not looked at other C30's but I have never seen one on a 3/4 ton that looks like mine

That's exactly what I was thinking.

[Bob B.]

I just ran into something strange, maybe you guys can help: I have a '67 3/4, want to put power brakes on it (drum-drum). I have the complete master cylinder and single diaphragm Delco booster off of a '70, linkage and all. I want to use the correct '67 dual diaphragm Bendix booster. The dual Bendix unit does not fit on the Delco brackets, and even if you could get it on there, the push rod out of the back of the booster (where it connects to the lever in the bracket assembly) is a lot shorter. NAPA says all 1/2 ton boosters are the same. 67-70, and all 3/4 ton boosters are the same, 67-70. What gives? Thanks, Bob.