Brake booster replacement - The 1947 - Present Chevrolet & GMC Truck Message Board Network

miket · 05-26-2003, 01:31 PM

How do you ID the Brake booster to buy the right replacement part?

trukman1 · 05-26-2003, 11:13 PM

Don't know if this will help but I only know of two boosters...The first is the single diaphram type that is of a larger diameter and thinner from front to back and the second is the dual diaphram version that is thicker and, if memory serves me right, is a smaller diameter. I swapped a unit from a '72 'Burb into my '67 and it turned out to be the dual diaphram type. It also uses a short throw plunger which only protruded about a quarter inch into the master cylinder vs. a longer (1" or more) plunger for the single diaphram booster. I used a stock corvette master with the shallow piston whereas the single diaphram unit used a plunger that extended out far more by at least an inch or more. I know this still doesn't give you much to go on but it's all I know to tell you right now. Hope this helps. Trukman1

JimKshortstep4x4 · 05-27-2003, 08:22 AM

Here is some information that may help you.

http://www.brakeboosters.com/booster.htm

In the picture, the top left is a Bendix and the bottom right is a
Delco booster. Out of the 9 trucks that we have with power brakes, (8) are Bendix and (1) is Delco.

Jim

No3Fan4Ever · 05-27-2003, 09:22 AM

Which one is the most likely to be on a 3/4 ton truck?

JimKshortstep4x4 · 05-27-2003, 10:15 AM

I don't remember which one might be for a 3/4 ton truck. They were usually the double diaphragm type. I have one that I can look at later today and post a pic if no one else does in the meantime.

Jim

JimKshortstep4x4 · 05-27-2003, 08:20 PM

Here is a pic of a 3/4 ton Delco brake booster, front view.

Jim

JimKshortstep4x4 · 05-27-2003, 08:25 PM

Here is a pic of the 3/4 ton booster side view. As can be noted it is thicker than a single diaphragm booster as it has two diaphragms in it. (The double diaphragm is approx. 6" thick and the single is approx 4" thick).

Jim

krue · 05-27-2003, 10:14 PM

I didn't recognize it without any rust!:p

Longhorn Man · 05-27-2003, 11:43 PM

I sold my repair manual, so i can't referance it nor name the manufacturers, but I believe there were actually 2 brands of daul diafram boosters that were quite differant

JimKshortstep4x4 · 05-28-2003, 08:34 AM

Andy,

I think that you are right on this. I took a dual diaphragm off of a 69 3/4 ton that was smaller in diameter and we used it on my son-in-laws 56 Chevrolet. The problem is there are no names or numbers on the diaphragms.

Jim

05-26-2003, 01:31 PM	#1
miket Registered User Join Date: Jan 2003 Location: Seattle WA Posts: 1,466	Brake booster replacement How do you ID the Brake booster to buy the right replacement part? __________________ FocuzTech Performance Evergreen Protective Coatings Gatorhyde...the best kept secret in spray in bed lining & protection

05-26-2003, 11:13 PM	#2
trukman1 Registered User Join Date: Apr 2001 Location: Beavercreek, Ohio 45431 Posts: 737	Brake Booster Don't know if this will help but I only know of two boosters...The first is the single diaphram type that is of a larger diameter and thinner from front to back and the second is the dual diaphram version that is thicker and, if memory serves me right, is a smaller diameter. I swapped a unit from a '72 'Burb into my '67 and it turned out to be the dual diaphram type. It also uses a short throw plunger which only protruded about a quarter inch into the master cylinder vs. a longer (1" or more) plunger for the single diaphram booster. I used a stock corvette master with the shallow piston whereas the single diaphram unit used a plunger that extended out far more by at least an inch or more. I know this still doesn't give you much to go on but it's all I know to tell you right now. Hope this helps. Trukman1

05-27-2003, 09:22 AM	#4
No3Fan4Ever Running on empty Join Date: Aug 2002 Location: Roanoke, Virginia Posts: 1,033	Which one is the most likely to be on a 3/4 ton truck? __________________ _____________________________________________ Tim We have two rules here at the Rock. Rule #1: No writing on the walls. Rule#2: Obey all rules 70 GMC Sierra Grande "Custom Camper" Longhorn 402 Big Block TH400 PS PB factory AC Posi; 94 Bronco XLT 302, auto;worn out daily driver

05-27-2003, 08:20 PM	#6
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	Here is a pic of a 3/4 ton Delco brake booster, front view. Jim Attached Images

05-27-2003, 08:25 PM	#7
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	Here is a pic of the 3/4 ton booster side view. As can be noted it is thicker than a single diaphragm booster as it has two diaphragms in it. (The double diaphragm is approx. 6" thick and the single is approx 4" thick). Jim Attached Images

05-27-2003, 08:22 AM	#3
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	Here is some information that may help you. http://www.brakeboosters.com/booster.htm In the picture, the top left is a Bendix and the bottom right is a Delco booster. Out of the 9 trucks that we have with power brakes, (8) are Bendix and (1) is Delco. Jim

05-27-2003, 10:15 AM	#5
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	I don't remember which one might be for a 3/4 ton truck. They were usually the double diaphragm type. I have one that I can look at later today and post a pic if no one else does in the meantime. Jim

05-27-2003, 10:14 PM	#8
krue Designated A-hole! Join Date: Mar 2003 Location: South Mississippi Posts: 36,448	I didn't recognize it without any rust!:p __________________ "If it ain't broke, fix it 'til it is!" Being stupid ain't illegal. We're Still Debt Free Except for the House!!! www.daveramsey.com 70 GMC SWB Stepside project "Green Booger" soon to be 6.0l/4l80e 93 S-10 "Poppaw's Truck"

05-27-2003, 11:43 PM	#9
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	I sold my repair manual, so i can't referance it nor name the manufacturers, but I believe there were actually 2 brands of daul diafram boosters that were quite differant

05-28-2003, 08:34 AM	#10
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	Andy, I think that you are right on this. I took a dual diaphragm off of a 69 3/4 ton that was smaller in diameter and we used it on my son-in-laws 56 Chevrolet. The problem is there are no names or numbers on the diaphragms. Jim



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