Factory Manual Brakes Question

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JBsCamino

Not-quite-so-new-guy
Jan 5, 2016
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Here is the master cylinder from the car. It has the longer pushrod, and a factory pushrod retainer cup to keep the pushrod from falling out.

I am guessing the pushrod retaining cup is just kind of pressed into the back of the master cylinder and I can hopefully yank/pry it out of there without damaging it to swap it over a new master cylinder.


 

oldsmobile joe

Royal Smart Person
Nov 12, 2015
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upon further review, even though i have never seen one, the info i found in a book titled American Cars, 1973-1980 by J Kelly Flory, jr; the 78-79 gbodies, (A bodies) came standard with manual brakes. obviously, most came with power brakes, some of these were part of an option package that required power assist.
the station wagons, grand prix, grand am and regal sport all came with power brakes as standard equipment.
power brakes became standard across the line of gbodies starting in 1980.

or did they, the following info i found on the rock auto web site indicates that malibu and le mans had the manual brakes available through 1980.
BUICK CENTURY 1978-1979
BUICK REGAL 1978-1979
CHEVROLET MALIBU 1978-1980
CHEVROLET MONTE CARLO 1978-1979
OLDSMOBILE CUTLASS 1977-1979
OLDSMOBILE CUTLASS CALAIS 1979
OLDSMOBILE CUTLASS SALON 1979
OLDSMOBILE CUTLASS SUPREME 1979
PONTIAC GRAND AM 1978-1979
PONTIAC GRAND LEMANS 1978-1980
PONTIAC GRAND PRIX 1978-1979
PONTIAC LEMANS 1978-1980

minor discrepancies

but i don't know what to say about the two piece plate. or the small (manual trans like) brake pedal.
 

malibudave

Greasemonkey
Mar 12, 2010
204
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Houston, TX
Hello all,

Stock manual brake equipped "g-bodies", 1978-1979ish came with the small brake pedal pad like described in an earlier post. The studs coming through the firewall are part of the brake pedal assembly and are pressed or welded onto the brake pedal bracket. The retention cup, that the pushrod is in, is a separate piece and looks as if it is rusted to the master cylinder in the picture. I didn't think the stamped steel plate was two pieces, but I have never actually seen an actual "g-body" with manual brakes.
 

Ribbedroof

Comic Book Super Hero
Supporting Member
Jan 4, 2009
4,861
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Wellston, OK
From the MVMA specs for the 1978 Chevrolet Malibu, Malibu Classic, and El Camino:

upload_2016-2-6_18-48-34.png


A I read it, manual brakes could be had ONLY with a NON-A/C V6 car

The 1981 specs show PB as standard on all applications
 

pontiacgp

blank
Mar 31, 2006
29,270
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Kitchener, Ontario
I was wrong about G bodies never coming with manual brakes.....from the maluburacing forum..

"Converting from power brakes to manual brakes is becoming a popular swap for A/G-Body car owners. Especially if you are running a large cam, causing your engine to produce a weak vacuum and rendering your power brakes virtually unusable. There are plenty of aftermarket parts available, but the costs can become expensive rather quickly. What many do not realize is that manual brakes were available on A/G-Body cars. My '79 Malibu came from the factory with manual brakes, so I simply bought new parts as I rebuilt the brake system. The only real change is the master cylinder, pedal pushrod, and a pedal pivot point relocation.

A quick call to NAPA autoparts here locally confirmed that the manual & power master cylinders carry different part numbers. My local dealer did not stock the manual pieces, but could order them for me. The manual piece was $31.75 rebuilt, and $127.66 new.


new_mc_side_tn.jpg


To make the conversion, the original power booster & cylinder needs to be unbolted from the firewall & discarded. A small aluminum plate should be fabricated to cover the large hole in the firewall where the booster previously mounted. 1/8" thick aluminum should be fine as it is just a cover plate. The new manual master cylinder will slide onto the top two studs sticking out of the firewall. The brake pedal pushrod pivot pin is in the lower hole on a power car, and needs to be moved to the upper hole on a manual brake car. This higher hole allows for the proper pedal ratio and line pressure. I doubt anyone will be lucky enough to find a manual brake activation push rod, so a one will need to be fabricated from scratch. This swap is quite simple to accomplish with little customizing and risking poor braking performance due to mismatched aftermarket parts. Using a rebuilt master cylinder can limit cash outlay to less than $75 for the conversion.

BTW, many parts store master cylinders will not look anything like the factory piece. Mine was made by Bendix and included paperwork warning of the visual difference, but stated that performance was identical."
 

JBsCamino

Not-quite-so-new-guy
Jan 5, 2016
37
6
8
I paid $22 for the set up, which $20 of was for the master cylinder which I will end up buying a rebuilt unit anyways, but was worth it to get the pushrod and pushrod retainer cup. Will post an update in my build thread once it gets swapped.
 

oldsmobile joe

Royal Smart Person
Nov 12, 2015
2,067
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if your talking about the intermediate shaft between the column and gear? i believe it is a shaft from a jeep grand cherokee. the one i have looks like it and came from a "94 grand cherokee. they can be found on other vehicles. do a search for more info
 
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