Adding power brakes - The 1947 - Present Chevrolet & GMC Truck Message Board Network

ZZ4Blazer · 06-29-2009, 03:55 AM

Working on my 67, manual brakes. Swapping the power brake unit to it from my 68 that is fully loaded.

Problem is the rod connecting to the brake pedal through the firewall is about 1/2" too short on my 67. What gives? Pedals appear the same, and mounting hole both seem to be in the same place on the pedal(I measured)

**N2TRUX** · 07-02-2009, 10:35 PM

Anyone?

SCOTI · 07-03-2009, 08:12 AM

Power brakes require a different length rod. I had to combine part of my original rod w/another from the donor vehicle when I swapped to power discs on my 68.

msgross · 07-03-2009, 08:21 AM

I think you need the adjustable rod from the 68, I have also heard that guys moved the mounting hole higher on the pedal..

ZZ4Blazer · 07-03-2009, 01:57 PM

Im sorry if I didnt make that clear. Im using the entire unit from my 68, including the adjustable rod off the pedal from my 68 as well. The 68 has a threaded rod that connects to the pedal on one side, and then to the booster linkage on the other.

The 67 had a rod that connected to the pedal, but then straight into the master cylinder because it was manual brakes.

Im more interested in why its different between 2 trucks only a year apart. I obviously just need a longer rod. I'll see if I can use a peice of all thread, or I'll make a new rod and pick up some tiny rod ends up from summit.

SCOTI · 07-03-2009, 03:56 PM

Quote:

Originally Posted by ZZ4Blazer

Im sorry if I didnt make that clear. Im using the entire unit from my 68, including the adjustable rod off the pedal from my 68 as well. The 68 has a threaded rod that connects to the pedal on one side, and then to the booster linkage on the other.

The 67 had a rod that connected to the pedal, but then straight into the master cylinder because it was manual brakes.

Im more interested in why its different between 2 trucks only a year apart. I obviously just need a longer rod. I'll see if I can use a peice of all thread, or I'll make a new rod and pick up some tiny rod ends up from summit.

Mine was a 68 w/manual drum brakes. I swapped to pwr discs using a 71-72 firewall bracket/z-bar, 71-72 power booster, & 73-up master cylinder. When I went to adjust the rod for the new combo, like you, I found it about .500 to .750" too short. I spliced the 68's OE rod w/part of the rod off of the 75 donor truck I got my swap parts from.

I always thought the manual to power difference was a different hole in the pedal which affected leverage. I guess the rods are different as well.

06-29-2009, 03:55 AM	#1
ZZ4Blazer Registered User Join Date: Aug 2004 Location: Akron, OH Posts: 95	Adding power brakes Working on my 67, manual brakes. Swapping the power brake unit to it from my 68 that is fully loaded. Problem is the rod connecting to the brake pedal through the firewall is about 1/2" too short on my 67. What gives? Pedals appear the same, and mounting hole both seem to be in the same place on the pedal(I measured)

07-02-2009, 10:35 PM	#2
N2TRUX Happy to be here Join Date: Mar 2000 Location: Cypress, TX Posts: 39,021	Re: Adding power brakes Anyone? __________________ Follow me on Facebook and Instagram @N2trux.com Articles- "Jake" the 84 to 74 crewcab "Elwood" the77_Remix 85 GMC Sierra "Scarlett" "Refining Sierra"

07-03-2009, 08:12 AM	#3
SCOTI Registered User Join Date: Apr 2001 Location: DALLAS,TX Posts: 22,071	Re: Adding power brakes Power brakes require a different length rod. I had to combine part of my original rod w/another from the donor vehicle when I swapped to power discs on my 68. __________________ 67SWB-B.B.RetroRod 64SWB-Recycle 89CCDually-Driver/Tow Truck 99CCSWB Driver All Fleetsides @rattlecankustoms in IG Building a small, high rpm engine with the perfect bore, stroke and rod ratio is very impressive. It's like a highly skilled Morrocan sword fighter with a Damascus Steel Scimitar..... *Cubic inches is like Indiana Jones with a cheap pistol.*

07-03-2009, 08:21 AM	#4
msgross Registered User Join Date: Jul 2006 Location: Central PA Posts: 12,201	Re: Adding power brakes I think you need the adjustable rod from the 68, I have also heard that guys moved the mounting hole higher on the pedal.. __________________ The Garage: 1968 K-10 SWB - "Project Money Pit" 1996 Z-71 - "huntin rig" 1969 C-10 LWB (SOLD) "Project flip that truck or else" 1993 Passport, F@rd 1-ton (SOLD)"Project Cousin Eddie" My Garage Build "The 1,000 footer" Last edited by msgross; 07-03-2009 at 08:22 AM.

07-03-2009, 01:57 PM	#5
ZZ4Blazer Registered User Join Date: Aug 2004 Location: Akron, OH Posts: 95	Re: Adding power brakes Im sorry if I didnt make that clear. Im using the entire unit from my 68, including the adjustable rod off the pedal from my 68 as well. The 68 has a threaded rod that connects to the pedal on one side, and then to the booster linkage on the other. The 67 had a rod that connected to the pedal, but then straight into the master cylinder because it was manual brakes. Im more interested in why its different between 2 trucks only a year apart. I obviously just need a longer rod. I'll see if I can use a peice of all thread, or I'll make a new rod and pick up some tiny rod ends up from summit.



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