Brake master cylinder refill plugs availability.

[sreeves]

Does anybody know where I can find new brake master cylinder screw-in refill plugs? You know, the ones that you unscrew to refill or top off the master cylinder with brake fluid. I have one that when the brake is applied, the plug leaks because it doesn't fit tight enough. Thanks

[Roesbery]

Most of the plugs have a vent hole in them. Your reservior is probably a little over full, causing the venting of fluid instead of air. When it quits leaking it will be "just right". And you will have all that anti corosion stuff in the belly etc.

[zero.one.victor]

Ditto Roesbury's comments about the vent holes & "burping" of fluid. That's not a problem-- that's a feature! Self-correcting fluid level, and automatic corrosion control. Actually two features in one.
If you do decide to replace the plugs, I'd determine the size & thread and look for a suitable replacement at your local Napa or Ace Airmotive. Plastic plugs are easy to modify with the vent hole-- a very small drill bit or a hot poker will do the trick.

Eric

[Dave Clark]

It's a 1/8 pipe plug. I like the plastic ones, especially when they're free on the back of instruments sent back after repair. Whoops, I guess that was not "free"

[N2865C]

I had the same experence. Mine stop leaking when they are about 3/4 full. The caps should be vented and there are instructions for drilling the holes in the 100 series service manual.
jc