What size brake line fittings are in proportioning valve?

[Turbo Regal]

I am needing to know what size are the steel fittings for the left and right brake calipers where they screw into the proportioning valve? I believe they are metric but I am not sure.

My proportioning valve is the brass one. This is on a 1987 Buick Regal.

I need to know the body size and thread count if at all possible.

Thanks!

 

[bjohn07]

Re: What size brake line fittings are in proportioning valve

not to sure on the sizes. but im assuming u have it off already. u can go to any auto parts store and usually they will have a brake line fitting assortment case. just ask them if u can use it to figure out what size u need and then just by the single ones instead of gettin the whole assortment

 

[FE3X CLONE]

Re: What size brake line fittings are in proportioning valve

The G-body still used SAE threads, no metric.

I don't remember what mine were off hand because I bought stainless lines already bent up but if I was to guess, they were the 3/8-24.

But as mentioned, do you have the proportioning valve off the car? If so just take it with you to the store and test fit a couple of fittings. Or you can go to the hardware store and test fit a couple of bolts which would tell you what the thread was.

 

[Turbo Regal]

Re: What size brake line fittings are in proportioning valve

If the G body doesn't use metric threads that's news to me.

Someone told me a 3/16 fitting would work. It does not. I have a piece of brake line that has 3/16 fitting and it doesn't fit the prop valve. Also I have a 3/16 plug they said would fit. It doesn't. It still allows fluid leakage and is sort of loose when threaded in the prop valve.

I do not have the prop valve off of the car. I was hoping to not have to remove it. Looks like I'm going to have to though. Bummer.

Well if anyone happens to know off the top of their head please let me know. Thanks.

 

[FE3X CLONE]

Re: What size brake line fittings are in proportioning valve

The front brake lines themselves are 3/16" but the fittings are larger.

Had to go digging through all of my old information on my car but found that it appears the two front 3/16" brake lines use the 3/8-24 nut.
The fitting out the back of the valve with the 1/4" brake line is a 9/16-18. The two on top of the valve coming from the master cylinder are different in size to keep from mixing them up. Don't remember their size off hand.

You'll also notice, although I'm sure by now the coating on the fittings has wore off, that the nuts themselves are color coded. When you buy new brake lines/nuts, they'll be color coated as well. I know the 3/8-24 fittings are gold and the 9/16-18 fitting is blue.

Your best bet, if you don't want to remove the valve from the car would be to go buy a couple different sizes bolts and check for sure.

I'd start with a 3/8-24 bolt to check the lines your talking about. I bet that fits.

 

[joe_padavano]

Re: What size brake line fittings are in proportioning valve

If the G body doesn't use metric threads that's news to me.

Someone told me a 3/16 fitting would work. It does not. I have a piece of brake line that has 3/16 fitting and it doesn't fit the prop valve. Also I have a 3/16 plug they said would fit. It doesn't. It still allows fluid leakage and is sort of loose when threaded in the prop valve.

I do not have the prop valve off of the car. I was hoping to not have to remove it. Looks like I'm going to have to though. Bummer.

Well if anyone happens to know off the top of their head please let me know. Thanks.

The first problem is that the threads on the flare nut are NOT related to the tube diameter. The pre-flared tubes in auto parts store only come with one standard thread for a given tube diameter, but the factory used several different thread sizes so the lines would not be improperly installed on the assembly line. You can get these "non-standard" nuts from the tubing specialty houses like Inline Tube and Right Stuff. Alternately, if the old fittings are in good shape, reuse them and reflare the tube.

 

[RITTER]

Re: What size brake line fittings are in proportioning valve

The colored flared nuts are adapter nuts (3/16 line with say a 5/16 flared nut size) You should be able to get these at your local parts store also. We also sell the preflared lines with adapter nuts on them.

 

[Turbo Regal]

Re: What size brake line fittings are in proportioning valve

You'll also notice, although I'm sure by now the coating on the fittings has wore off, that the nuts themselves are color coded. When you buy new brake lines/nuts, they'll be color coated as well. I know the 3/8-24 fittings are gold and the 9/16-18 fitting is blue.

Interesting, the 1/8 NPT fittings are also gold colored.

I'll look into the3/8-24 fitting. Thanks!