Master brake cylinder replacement woes

[Summershandy]

I just got my new '54 cylinder and it doesn't have an inlet for my brake lamp switch like my original. I wanted to replace it instead of a rebuild as the rest of the system. I'm told this is the correct master. Also told from what I'm understanding, the brake switch goes in the junction box. I have a schematic from Early Times that shows my system perfectly. I searched the internet and can't find a replacement cylinder that accommodates my brake switch. I know all about the mechanical switches guys have been changing out with but I really want to keep the original. Guess it's just a rebuild then? 

[Guest]

Can't you just by a "weatherhead" tee and put your stop light switch on the side take off and your brake line on the tee instead of the cylinder???

 

This is just a sample, many other sizes/configurations available.

Eaton Weatherhead 3750X6 Brass CA360 Fitting, Street Tee, 3/8" NPT Female x 3/8" NPT Male x 3/8" NPT Female

[PONTIAC1953]

it depends on if summershandy's pontiac has the standard brakes or the treadle vac power brakes.

[Summershandy]

Standard non powered brakes. I can do this? Because of not knowing this type of switch, I had assumed it had to be where it was. So the pressure will still work away from the cylinder? Does the switch have to be in the upright position? Ooooo, I got questions and getting revved up again!

[Summershandy]

Man, I'm starting to get tired of apologizing for being the idiot that I am! Here we go assuming things like the brake light switch goes in the top of the cylinder. I crawled underneath and took a couple pictures. The brass junction box I thought the supplier was referring to was the one where all the lines meet. Nope. At the front of the cylinder is the weatherhead fitting that Tinindian posted. Guess with all the dirt I thought it was all part of the master. I do have the proper one. Once again, sorry for the inconvenience. I do however, appreciate all your feedback and inspiration!

 

 

 

[Guest]

No inconvience.

[PETEPONTIAC-1]

If you are going to rebuild your master cylinder. NAPA has a kit NAPA # UP 3, that works for my 38 Pontiac, and your master cylinder looks like mine . Worth checking out NAPA, cheaper to. PP 

 

PS. Also NAPA has Stop light switch # ECH SL113 .

FYI  

Edited March 9, 2018 by PETEPONTIAC-1 (see edit history)

[Summershandy]

Thanks PP, I haven't much luck with NAPA here in Canada for parts. I know the boys pretty good. I hate taking chances kits will fit too. I'm sinking some good money in this so a little more shouldn't hurt. Thanks for the FYI, it's always good to know alternatives. Cheers!

[pont35cpe]

You should replace the copper washers on the banjo fitting(piece the switch screws into), because they will most likely leak if not put back on exactly as they come off..

[Summershandy]

5 hours ago, pont35cpe said:

You should replace the copper washers on the banjo fitting(piece the switch screws into)

 

Thanks for the heads up!

[Bloo]

If it were me, I wouldn't disturb the huge copper washer at the back of the cylinder bore (closest to the mounting ear) if possible. I say if possible because I'm not sure if you have to remove it to get the piston out. I don't think you do.

 

I saw one of those big washers (on a Buick) leak with a persistence I have never seen in a brake system. It defied all attempts to seal it including a new copper washer, annealed old copper washers, custom machined thicker copper washers, aluminum washers, re-machining the sealing surfaces level and square, etc. I have no idea why it wouldn't seal.

 

If I remember correctly the owner had it machined for a rubber o ring after days of trying. That worked, but as the trouble was never solved using original materials, I am very reluctant to take that last copper washer off.

Edited March 9, 2018 by Bloo (see edit history)