OK, got the new proportioning valve. All lines sizes on the valve match up well with my set up, EXCEPT the two inlets for front and rear.

The rear inlet line size on my truck came with a 3/8-24 while my front inlet line size is 7/16-24 . On the new proportioning valve, the inlet line for the rear is 7/16-24 and the inlet line for the front side is 1/2-20.

What are the fittings called that convert one size fitting to another. Inverted flare? Best place to get them?

thanks-

 

Inverted flare adapter. NAPA has them. I just got a couple from NAPA last week.

 

Deleted! Brain fade....

 

So is it a 7/16-24 female inverted flare to 1/2-20 male NPT?

I don't think the male side would be NPT - it would have to be flare too? I know the inverted flare inlet on the NEW proportioning valve is 1/2-20, so what do you call the male side that fits into it?

 

These are adapter fittings made specially for inverted flares. They're not NPT threads.

 

http://www.parker.com/literature/Bra...ts/3501E-H.pdf

I found this link by Parker. Go to 661FHD. But these are reducers. The male side is smaller than the female side. But mine needs to be:

Female inverted flare - 7/16-24
Male bubble flare - 1/2-20

 

Bubble flare? Everything on these trucks should be inverted flare as far as I know

Is this what you're looking for?

Buy American Grease Stick Co. Brass Adapter - 1 Per Package - 7/16-24 Inverted to 1/2-20 Inverted BLF-19C at Advance Auto Parts

 

Why do you need a bubble flare?

 

don't you need the male threaded end of the adapter to have the same type of fitting as the brake line has? It has a bubble flare.

 

I extremely doubt that it has a bubble flare, if it does something has been changed.

 

This is a bubble flare followed by a standard double flare

 

My mistake guys - i was using bubble incorrectly. The ends of our brake lines are a standard double flare. So back to my original question - don't I need an adapter that would have:

7/16-24 inverted flare (female)

1/2-20 double flare (male)

 

There are fittings designed exclusively to adapt one size inverted flare to another size inverted flare. NAPA has them, Autozone has them, O'reilly's has them.
Don't bring double flare into the picture. ALL stock brake lines have a double flare on the ends. A double flare uses the same fittings as a tube with a single flare.
This is what you're looking for.

You're putting more thought into this than you need to, just tell the parts guy you need an inverted flare adapter.

 

OK, adapters both installed into the new proportioning valve and all lines installed and brakes bled. they seem to work very well (the brakes) even though they are manual. Every single component to the brake system is new, including fluid.

Now here's the issue. There seems to be seapage or leaking at where the adapter screws into the proportioning valve. Both my adapters (BLF-22C and BLF-19C) are inverted flare to invereted flare and are correct thread pitch/size. It's the male end of the adapter that almost seems that its not making contact (with the flare fitting) down inside the proportioning valve. I torqued down both adapters, against better judgment and experience, and the rear inlet seems to have stopped leaking. But the larger one still leaks. I know the fittings from AGS are not AN type flares (e.g. 37 degree), so that's not the issue. would you say the issue is with the prop. valve with the flare fittings? Could the adapters not be making seal with the flare fitting inside the prop. valve? I'm also wondering if a better approach would be to just get a local hydraulic fab shop put the correct thread and pitch fittings on my MC to prop valve lines. Although it should be the same, it seems that a brake line with double flare fitting may fit up against the flare inside the prop valve better than an adapter??

 

Sometimes you just have to tighten the crap out of brake lines. Your talking around 700 to 1000 psi here. I've had to tighten them way more then I thought was safe from stripping them before to stop leaks. It's just the nature of brake lines.