The Stovebolt Site Forums The Shop Area Engine Shop master cylinder junction box/valve???

Hello, I have a 55 1st stock.
I'm looking for the part on the rear of the master cylinder that the brake lines go into. I hear this "junction box" is hard to find. Mine is a newer one looks newer at least. Tried new lines etc.. but still leaks. Any advice would be grand, thanks!!!
pjdee

PJDEE,

I'm trying to remember how my '54 3/4 ton is set-up...

I'm pretty sure there's just one line coming-off the MC (hole is set-up with a 1/4" female inverse flare), which runs across the crossmember under the bellhousing, to the right-hand frame rail.

There it meets a brass block with three female 1/4" tappings: one line goes to the front wheels ('nother block at the RF wheel, line crosses back at the front x-member to the LF); the other line runs back the right frame rail to the flex hose at the rear axle...

( This is definitely how my '55 first 1.5 ton is plumbed...)

If you have a deal with a junction block held to the MC by a fluid bolt, that might be a challenge...try going to a place that services big trucks and see of they match-up your fitting...Willys used a "Y"-type block on their master cylinders...


Good luck...

Thanks Frank for the advice!
I'll see what I can come up with, it seems like it is the only part of the entire brake system that you can't buy. I'm pretty sure the plumbing on mine is that two lines come out of the block one goes to the front driver's side wheel and the other goes to the other 3. Such a small little block of metal is giving me a large pain in the backside. Thanks again!
pjdee

PJDEE

I had the same problem on my '54 3100. Someone had cross-threaded one of the brakelines into the fitting on the back of the master cylinder. When I replaced the master cylinder, I couldn't get it to stop leaking.

I took it to my local NAPA store. He walked back and picked one up off the shelf. I think it was around $7.00

Good Luck.

Guys thanks so much for your advice and Joe thanks for the pictures. I ended up taking the block to NAPA and the manager seemed to think he could save it. If not I'll email you Joe. Again, what makes this such a great hobby/board is that people always are willing to share their hard earned knuckle bustin wisdom.
pjdee

Those type of fittings are called "banjo" fittings and Chevrolet used them from 1936 ( the first year they offered hydraulic brakes) up into the 60's. "Banjo" fittings came in several various configurations. In the last few years, they have become harder to find. Some of the 55-56-57 car suppliers offer them, or at least ones that will work. They allowed you to install a line, or more than one line, and also gave you a spot to install a hydraulic stoplight pressure switch.

The idea behind these fittings is that one fitting could be used to address several different configurations depending on the vehicle they were used on. The key to using these fittings is to use new copper washer gaskets each time you install one of these fittings. Supposedly you can take a used washer gasket, heat it in an oven and successfully re-use it. I have never had any luck doing that and found that new ones are a better choice.

Raybestos and some of the other brake parts manufactures still list these copper washer gaskets in their catalogs.

Joe

Copper washers...

Blister-pack stores that carry Motormite / Help! stuff often have packs of copper washers...

PEP Boys also usually have that kind of stuff...

Thanks again guys for all your help and advice.
Napa worked their magic and I was able to use the
my old junction block. Back on the road again!

June, July and August get all the PR but you can't beat September!