I'm putting a '68 drum/drum master cylinder in a '65 truck to upgrade the single circuit brakes. Which port on the '68 M/C goes to which axle?? Both reservoirs are the same size. Thanks in advance!
49 Chevy 3600 65 Chevy K10 48 International KB-1 Service Truck 55 Willys CJ5 - Chevy 331 powered 26 Model T Roadster Rat Rod 70 Tucker Sno-Cat 442-A 96 Dodge 3500 Cummins dually flatbed x-cab 4x4 06 Jeep Wrangler LJ rock crawler If you can't fix it with a hammer, it's an electrical problem
The below 1st screen shot shows the brake cylinder/hydraulic line circuits and corresponding connections taken from the 1967 Chevrolet Truck Engineering Book. Couldn't locate a 1968 version of the book, but a check of the May 1979 Chevrolet Master Parts Catalog (see 2nd screenshot) shows the same master cylinder was used for C10's from 1967-70.
The connection diagram would be the same for your '68 master cylinder as it is the same part for those year applications.
I would note that your '68 master cylinder was originally installed with a warning light switch assembly for the '67-'70 model years. That switch may or may not be needed for your '65 application. Hopefully someone else will chime in with more details or experience/knowledge.
Hope this info is helpful.
Dan
EDIT NOTE: I have submitted a flag to relocate this thread to either the Driveline or 60-66 Trucks forums as it doesn't fit into this forum.
Last edited by Gdads51; 04/13/202310:10 PM. Reason: Edited to correct info about brake switch
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49 Chevy 3600 65 Chevy K10 48 International KB-1 Service Truck 55 Willys CJ5 - Chevy 331 powered 26 Model T Roadster Rat Rod 70 Tucker Sno-Cat 442-A 96 Dodge 3500 Cummins dually flatbed x-cab 4x4 06 Jeep Wrangler LJ rock crawler If you can't fix it with a hammer, it's an electrical problem
I installed one on my 1963 C10 when I still had drum/drum brakes. I made a video. Some parts of the video will not apply to your 1965 C10. As I recall, the 1965 brake pedal pushrod is longer than the 1963 pushrod. I honestly don’t think it matters if the rear brakes use the front or rear port on the MC. Dual MC upgrade C10 video
Is the diameter of the dual circuit MC piston the same as the single line cylinder? If not, you'll be opening up a Pandora's box of potential problems, including some deadly dangerous ones. Jerry
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