Help with leak at wheel cylinder connection (1935 KC)

[jimy]

After my first longish drive this year I noticed a brake fluid leak at the rear of my 1935 (second series) KC pickup, 

 

After cleaning it up and pressing the pedal hard, I pretty much convinced myself the leak was where the brake line connects to the brass fitting at the wheel cylinder.  But I am not 100% sure (I should have waited for a helper so I could watch it drip).  When I disconnected the line from the fitting I saw several odd things there - first some of the "coating" from the brake line was where the flare met the fitting, and there was also a metallic paste (looked like aluminum from anti-seize) on the threads.  Don't know if either had any effect or if the paste was a previous attempt to seal or perhaps came from the brake line fitting as it was tightened?

 

In any case I have a few questions.

 

1 - The brass fitting has "rings" where the copper washers go.  The washers have rings to match.  I assume these formed as the bolt was tightened and the copper washers are not reusable?

2 - Perhaps the brass fitting is damaged where the flare from the line meets it?  Is this a standard auto parts store item?

3 - The line looks "ok" to me - is there a good way to know for sure or should I just replace?

 

I did initially snug everything up and that did not stop the leak.

 

thanks,

 

Jim

 

 

 

[Pete in PA]

1) True, true, and true.  Replace those washers and your leak will almost certainly go away.

2) In 1935, maybe.  Today? LOL  Replace the washers and try again.

3) The line is probably fine.  You've got a mismatch where old lines in the copper washers are not aligned with the lines on the brass fitting.  Replace the washers!

Are you seeing a pattern here?

Edited June 13, 2017 by Pete in PA (see edit history)

[Taylormade]

I would strongly advise annealing the new washers before you use them.  I have found the modern washers to be too hard, they won't crush properly.  Heat the washer to cherry red with a propane or MAP torch and let them air cool.  Be careful, you can melt the washer if it gets too hot.  As soon as it's cherry red, back the heat off.  You can hold the washer with needle-nose pliers.

 

Also, throughly clean the brass fitting and check for cracks.  Two of the fittings on my 32 DL were cracked, probably from over tightening.

[jpage]

I had the same issue so I took the old washers and carefully sanded them flat to remove the rings. Also, the old flare can leave a footprint in the seat of the fitting that may not seal with the new line. I don't know of a good way to fix that and these old banjos are not available new.

[nearchoclatetown]

The washers can be bought. Either a real auto parts store or McMaster-Carr will have them.That is probably your problem. 

[JACK M]

Look carefully at the female of the flare fitting. I had one that was cracked once that drove me crazy.

Could not see it when the line was off, but it would open up when the line was tightened.

I have also had issues with the washers so I guess these posts have just about covered all of your parts.

[jimy]

Thanks for the help.  I ordered some new washers and will anneal them before installation.  

 

My real auto parts store (NAPA) had a nice tray of assorted copper washers, with nearly every size missing.  I ordered online.

 

Jim

[Rusty_OToole]

I was told many years ago that copper is the opposite of steel, you need to quench to soften it. I was taught to lay the washer on a piece of steel, heat it up and let it slide into a container of water. You can't heat copper red it will melt but it does change color. You just need to heat it enough to soften a bit.