I have a 68 442 which i converted to front disc brakes (1971 model with single pistons) and i am on my second proportioning valve in 2 weeks due to the fact that it leaks from the metering valve. Its made by MBM model PV2. I used silicone brake fluid as i put new stainless steel lines as well. I can i stop it from leaking? Do i need to remove the metering valve and sealed it with white tape used for brake lines? Is it due to different viscosity? Please help.

 

The combo valve uses inverted flare fittings, which seal on the flare. Tape on the threads is useless; the threads DO NOT seal. If two new valves leak, the problem is probably not the valve but the flare on the line going into it.

 

 

Joe, what would you suggest i do to alliviate the issue? The leak is defenetely coming from the metering valve.

 

I understand you put new Stainless steel lines on this valve. I have done some double flares on regular tubing before, they looked perfect. BUT there was a tiny line on the face of the flare where the tubing was seamed that caused a leak. You might want to really closely examine those flares.
Just a thought.

 

If you are using stainless line, it has to be really really tight. I had the same problem when I switched my lines to stainless, it leaked at almost every connection. I had to tighten all of them as much as I could.

 

Tom, what did you do to fix the situation?

 

I did that, they are as tight as i could make them any more and they would strip the threads.

 

I had to re-bend the lines (lucky it was the front left) and they held the second time around...