Need advice ? Hooked up new disc brakes ,calipers , a lot of new suspension parts on my 1972 Cutlass . Im to where I need to plumb new lines but having an issue . The new proportional valve at the master cylinder cut out the distribution block on the frame . The rear 1/4 line have a 9/16-18 fitting and so does the prop. valve . I cant seem to find a coupler that size anywhere . How can I make this connection without running a new rear brake line ?

 

I had the same problem when I put my proportioning valve in to replace the distribution block. Could not find a coupler anywhere and I wound up running a new rear brake line. It was a *itch but it was the best solution I could come up with.

I heard rumors about a magic coupler for this problem but I never found one.

 

NAPA stores have a whole assortment box of these. Unfortunately, most of the counter workers don't even know it's in the store.

https://pitstopusa.com/c-320170-fitt...-fittings.html

https://www.oreillyauto.com/shop/per...gs---sae-18686

http://www.dormanproducts.com/c-176-...-adapters.aspx

 

This is what I need but the 9/16-18 coupler for 1/4 line doesn't exist . Its insanely confusing with all the brake upgrades that are sold to not have this simple piece .

 

Because no one needs it. The 9/16 flare nuts on 1/4" line are a non-standard size used by GM to preclude incorrect connections of brake lines on the assembly line. That line only fits into one threaded hole, period. No one connects them like this, they just reflare the line to use a standard nut - or better, just run a line of the correct length.

If you must use the old line, can get the adapter to neck the 9/16 down to the standard 7/16 and then just connect a line from there.