New WH Brake Master Cylinder Leak

[DeezNCSU]

Next on my list of problems is a leak on my Wild horses brake master cylinder, kit is K7045, which is essentially brand new. The paint is also new but this drip has caused it to bubble. Fluid leaks from the plug circled in the attached pic and no matter how much I tighten it or mess with it, there is no change. Fluid only drains out when I drive it, not when it sits. Planning to call WH on Monday, but is there some obvious and easy fix?

Google Photos

photos.google.com

 

[Speedrdr]

Have you checked the threads on either the plug that’s circled and/or the inner threads to see if there’s a piece of grit in the threads or a bad thread that’s causing the leak? Maybe not but can’t hurt to check.

Randy

 

[DeezNCSU]

I haven’t yet, didn’t want to drink and have to bleed them until I had some ideas.

 

[Apogee]

Those master cylinders advertise 3/8-24 inverted flare outlet ports on both sides, so the assumption is that those are 3/8-24 inverted flare plugs...those are 3/8-24 IF plugs, correct?

 

[DeezNCSU]

It looks like it based on what I just saw on google. I took it out yesterday to see if they threads on the plug and cylinder were clean and they were.

 

[Apogee]

An inverted flare fitting seals between the conical surfaces between the seat and the plug, so the threads should not be an issue so long as they're functional. Any leaks would be due to flaws in one or both of the sealing surfaces. If the flaw is in the plug, then a new plug might fix it. If the flaw is in the sealing surface on the outlet port on the master cylinder, then you would either need to fix that surface, add a band-aid like a conical crush washer, or replace the MC.

 

[Johnnyb]

I would suggest the inverted flare is the issue. As others have suggested, either there's crud on the surface or a crack/flaw in the flare.

-JB

 

[Oldtimer]

Next on my list of problems is a leak on my Wild horses brake master cylinder, kit is K7045, which is essentially brand new.

Check your paper work
K7045 is part number for Tom's power brake booster kit.
Master cylinder in your photo looks like WH 3083 part number.

 

[DeezNCSU]

Check your paper work
K7045 is part number for Tom's power brake booster kit.
Master cylinder in your photo looks like WH 3083 part number.

I think I had both sites open looking at something, it's definitely the 3050 from WH. I'm going to grab another plug from Autozone and see if that works.

 

[bronco italiano]

Interesting as I have the same style of MC and it too leaked on the plugged port side. Does the plug have the point on it?
I had to torque it pretty hard to stop leaking