I have a 55 1st series and am putting in an new single master cylinder like the original and stainless lines. My brake line to the master cyl is a 7/16 and it appears the new master cyl is a 1/2" connection. The adapters that I have seen both online and at the auto parts places don't seem to be long enough to reach the inside of the master cyl to make a good compression connection. I expect it will leak if it isn't long enough. I am not sure why the new one has a 1/2 in connection. Appreciate any advice.
Check with Speedway. they carry a line of fitting and should have what your looking for. You can talk to their Tech folks and let them know what your working on.
~ Craig 1958 Viking 4400 "The Book of Thor" Read the story in the DITY 1960 Chevrolet C10 "A Family Heirloom" Follow the story in the DITY Gallery '59 Apache 31, 327 V8 (0.030 over), Muncie M20 4 Speed, GM 10 Bolt Rear... long term project (30 years and counting)
If you don't like driving yourTruck, you won't drive yourTruck..| Living life in the SLOW lane
The 55.1 master cylinder does not have an inverted flare hole in the end of it. It requires a special banjo fitting, consisting of bolt with an inverted flare in the head of it. This bolt passes through a brass block which provides for attachment of an additional brake line. For some reason, this setup splits the front left wheel from the other 3 wheels at the master cylinder. Models prior to '51 did not. There was simply one single inverted flare on the end of the master cylinder which fed all four wheels. Carl
1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission
I replaced the brake master cylinder on my 1954 Chev 3100, and also couldn't find a replacement Banjo bolt fitting, so I bought new copper compression ring and reused the old one. I would like to find a new one if possible. Below is a picture of it.
Mine is an automatic which appears to have a different routing of the lines due to the transmission brace. The drivers side is fed across the front of the truck from the passenger side. As a result, it doesn't have a double connection at the master cylinder. I tried getting the old nut off the master cylinder so I could use the old 7/16 fitting, but wasn't able to get it off.
The clutch-transmission lines/fittings and master-cylinders are different for clutch trucks and Hydra-Matic trucks. Of course, due to the extra/different cross-members, the H-M lines-routing is also different from the clutch truck.
Keep all your old H-M brake line fittings (with small pieces of lines connected to each fitting). Draw a diagram of the routing of all lines.
Luckily, I was able to either reuse fittings and/or find new fittings (several years ago).
