Brake line fitting leaking at proportioning valve (2 Viewers)

[cims1970fj40]

I was working on bleeding my brakes yesterday and noticed that when my daughter was pushing on the brakes that brake fluid was spraying out where the brake line mates to the proportioning valve? Will a bad proportioning valve do that. The flare on the brake line looks ok to me. Any advice would be appreciated. Also it’s the original Fj40 proportioning valve they had from 76-80.

 

[charliemeyer007]

You should look at those surfaces with a strong light and a good hand lens. There are 4 surfaces; the front of the nut, both sides of the flare and the inside cone mound in the valve. Easy enough to get a clunk of grit trapped on a surface and then get imbedded but not flush.

I always try and push the tubing flare onto the cone before tightening down the nut when assembling. Everything "clean" doesn't hurt.

 

[charliemeyer007]

I guess that it might not have been tightened enough. Using a flare fitting wrench will help on not rounding the corners.

I'm not sure what the proper torque would actually be; however some people turn off the oxy/acetyl regulator valves with enough force to ruin the seats - perhaps your inspection of the working surfaces in your fitting will reveil something. If not I would try tightening a little more.

 

[cims1970fj40]

You should look at those surfaces with a strong light and a good hand lens. There are 4 surfaces; the front of the nut, both sides of the flare and the inside cone mound in the valve. Easy enough to get a clunk of grit trapped on a surface and then get imbedded but not flush.

I always try and push the tubing flare onto the cone before tightening down the nut when assembling. Everything "clean" doesn't hurt.

Thanks for the response. I did what you suggested pushing the tubing flare into the cone and solved the issue. Know onto the next leak.