4 Disc brakes w/what booster? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

betonj97 · 09-30-2007, 07:09 PM

Hello everyone,

I have ran into an issue with my truck, I recently got it registered and on the street. After figuring out I had a leak in the booster I decided to replace it. I went from a 3/4 ton booster to a 1/2 ton booster, and now my brakes suck! At high rpms they are fine but at idle it seems like not enough boost. This is what I have set up: 327 with an rv cam, 1.6 roller rockers, holley carb 650, vaccum booster is connected to the port on the intake manifold rpm perfomer, I have chevy stock disc in the front and lincoln mark V 9" with disc on the rear. Since i replaced my booster to the smaller one I've noticed a drastic change, so I am now contemplating on buying a 3/4 ton booster assuming that because the 3/4 ton booster has more vaccum space it will react better......but thats why I am here wondering if this is so.......
I searched around on the post and really diddn't find anything that pertained to running a 1/2 ton booster versus a 3/4 ton booster.
Thanks again!

wibilly · 09-30-2007, 07:24 PM

i belive the 3/4 and 1 tons have duel diaphrams i have a 3/4 tone boster on my 4 wheel disks and they work awsome. i used 4wd front roters and 76 eldorodo rear calipers and no other mods were required

betonj97 · 09-30-2007, 07:48 PM

Nice, I needed to hear someone was running the bigger one. Hopefully this will do the trick. Any other comments before I order the bigger booster????
Thanks again!

aventur1 · 09-30-2007, 08:52 PM

so would it makes sense to get the 3/4 booster for my 1/2 ton if I'm going to put rear disc on next year! I currently do not have a booster. 71

wibilly · 09-30-2007, 09:03 PM

from my understanding of what i have read here is that a 3/4 ton booster is a good upgrade weather or not you have disk brakes

aventur1 · 09-30-2007, 10:03 PM

Good, I have disc in front, might as well buy the 3/4 one.

betonj97 · 10-01-2007, 12:55 AM

I will let you guys know what the results are but I am certain this will do the trick especially because it works for someone already....thanks wibilly

herb101 · 10-01-2007, 09:23 AM

I'll second the improvement. My brakes sucked on the Blazer (71 4x4 w/35's) and I have the front-end damage to prove it! I went from the 1/2 ton to the 3/4 ton and saw a Drastic increase in brake perfomace for the same pedal effort.

Herb

betonj97 · 10-01-2007, 01:38 PM

NICE! I'm digging this even more, thanks for the reply! and sorry to hear about the reck

Ackattack · 10-01-2007, 02:17 PM

what about a hydroboost setup

wibilly · 10-01-2007, 11:01 PM

that is another option for an upgrade. i belive yukon jack went that route. if you have a highly modified engine producing low vacume that is the only way to go

betonj97 · 10-03-2007, 01:55 AM

OK OK OK I'm a happy camper......Got the 3/4 ton booster today and threw it in, took her for a test run.......wow, whole different truck. I never realized how much vaccum disc brakes actually needed but it made a huge difference. To those who are building or planning on converting to disc, go 71' 3/4 ton booster. You won't have regrets. I thank you guys for your posts

09-30-2007, 07:09 PM	#1
betonj97 Registered User Join Date: Jul 2006 Location: sAC Posts: 48	4 Disc brakes w/what booster? Hello everyone, I have ran into an issue with my truck, I recently got it registered and on the street. After figuring out I had a leak in the booster I decided to replace it. I went from a 3/4 ton booster to a 1/2 ton booster, and now my brakes suck! At high rpms they are fine but at idle it seems like not enough boost. This is what I have set up: 327 with an rv cam, 1.6 roller rockers, holley carb 650, vaccum booster is connected to the port on the intake manifold rpm perfomer, I have chevy stock disc in the front and lincoln mark V 9" with disc on the rear. Since i replaced my booster to the smaller one I've noticed a drastic change, so I am now contemplating on buying a 3/4 ton booster assuming that because the 3/4 ton booster has more vaccum space it will react better......but thats why I am here wondering if this is so....... I searched around on the post and really diddn't find anything that pertained to running a 1/2 ton booster versus a 3/4 ton booster. Thanks again!

09-30-2007, 07:24 PM	#2
wibilly Senior Member Join Date: Nov 2005 Location: northwestern wi Posts: 2,111	Re: 4 Disc brakes w/what booster? i belive the 3/4 and 1 tons have duel diaphrams i have a 3/4 tone boster on my 4 wheel disks and they work awsome. i used 4wd front roters and 76 eldorodo rear calipers and no other mods were required __________________ common sense isn't so common anymore

09-30-2007, 07:48 PM	#3
betonj97 Registered User Join Date: Jul 2006 Location: sAC Posts: 48	Re: 4 Disc brakes w/what booster? Nice, I needed to hear someone was running the bigger one. Hopefully this will do the trick. Any other comments before I order the bigger booster???? Thanks again!

09-30-2007, 08:52 PM	#4
aventur1 Registered User Join Date: Aug 2007 Location: Boise, Idaho Posts: 676	Re: 4 Disc brakes w/what booster? so would it makes sense to get the 3/4 booster for my 1/2 ton if I'm going to put rear disc on next year! I currently do not have a booster. 71

09-30-2007, 09:03 PM	#5
wibilly Senior Member Join Date: Nov 2005 Location: northwestern wi Posts: 2,111	Re: 4 Disc brakes w/what booster? from my understanding of what i have read here is that a 3/4 ton booster is a good upgrade weather or not you have disk brakes __________________ common sense isn't so common anymore

09-30-2007, 10:03 PM	#6
aventur1 Registered User Join Date: Aug 2007 Location: Boise, Idaho Posts: 676	Re: 4 Disc brakes w/what booster? Good, I have disc in front, might as well buy the 3/4 one.

10-01-2007, 12:55 AM	#7
betonj97 Registered User Join Date: Jul 2006 Location: sAC Posts: 48	Re: 4 Disc brakes w/what booster? I will let you guys know what the results are but I am certain this will do the trick especially because it works for someone already....thanks wibilly

10-01-2007, 09:23 AM	#8
herb101 Used Register Join Date: May 2005 Location: Live Oak, TX Posts: 379	Re: 4 Disc brakes w/what booster? I'll second the improvement. My brakes sucked on the Blazer (71 4x4 w/35's) and I have the front-end damage to prove it! I went from the 1/2 ton to the 3/4 ton and saw a Drastic increase in brake perfomace for the same pedal effort. Herb

10-01-2007, 01:38 PM	#9
betonj97 Registered User Join Date: Jul 2006 Location: sAC Posts: 48	Re: 4 Disc brakes w/what booster? NICE! I'm digging this even more, thanks for the reply! and sorry to hear about the reck

10-01-2007, 02:17 PM	#10
Ackattack Senior Member Join Date: Aug 2002 Location: Valley Center KS Posts: 3,524	Re: 4 Disc brakes w/what booster? what about a hydroboost setup __________________ Project Bruiser: 68 Pro-Touring C-10 5.3L / 4L60E Project Ironhide: 97 GMC Crew Cab 4x4 Cummins SOLD: '69 GMC 1/2T SWB TBI'd: Project No Buck Assembly Manual Index Sign up Thread!!! Factory Service Manual Index

10-01-2007, 11:01 PM	#11
wibilly Senior Member Join Date: Nov 2005 Location: northwestern wi Posts: 2,111	Re: 4 Disc brakes w/what booster? that is another option for an upgrade. i belive yukon jack went that route. if you have a highly modified engine producing low vacume that is the only way to go __________________ common sense isn't so common anymore

10-03-2007, 01:55 AM	#12
betonj97 Registered User Join Date: Jul 2006 Location: sAC Posts: 48	Re: 4 Disc brakes w/what booster? OK OK OK I'm a happy camper......Got the 3/4 ton booster today and threw it in, took her for a test run.......wow, whole different truck. I never realized how much vaccum disc brakes actually needed but it made a huge difference. To those who are building or planning on converting to disc, go 71' 3/4 ton booster. You won't have regrets. I thank you guys for your posts



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