VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1933-1936 Brake line fitting sizes

The original brass cylinder blocks that I had on my 36 Master brake lines were all 7/16-24 threads. The new brake line kit that I bought from The Filling Station also had 7/16" fittings on all ends,like my originals. However, the reproduction brass blocks that are supposed to replace these have mixed sizes. Wheel cylinder inlet blocks (476100), main cyl, pipe to rear brake (475969) were 7/16", but all the other NORS blocks had 3/8-24 threads. I would just re-tap the brass blocks, but they're thinner than the originals, and there's not enough room to tap the larger threads. Should I try to find 7/16-24 to 3/8-24 adapters? That's not ideal, as my preformed brake lines won't fit well. Any other ideas?

Just looked again through the Filling Station catalog. They list a brass brake line connector for the rear axle as having a 3/16" opening (for 3/16" brake line I assume; FS part number SA-305). The application listed is 1936-65. But they have another connector with a 1/4" diameter, which should be correct for 1936, since these lines are 1/4". However, the application listed is 1951-1966 (part no. SA-306). Would this be the correct connector? I'm curious now about which cars used 3/16" brake lines.

The 1951 and up cars with the "new" Bendix brakes were the first to have 3/16" lines.
So far I haven't taken the time to look up the parts in the FS catalog.

The block for the rear should have a 7/16-24 opening on either side og the block to accept the inverted flare nut found on the ends of the 1/4" lines used in 1936-50.The single opening should have the 7/16 X 20 thread to accept the end of the brake hose.The part number for this fitting was 497756 and it was used on 1936-1950 cars and trucks and larger 1951-59 trucks (3/4 ton and up). Probably fits newer trucks but I am looking at a 1951 and 1959 book.This leads me to believe that the FS #SA 305 SHOULD be correct.
Note that 306 is listed for 1951-66 1/2 ton trucks which would have the smaller 3/16 brake lines.
Note that Chevs of the '40's have the 497756 and 476100 blocks...do you have their catalog?
The Chevrolet parts book shows the 476100 as connector,rear pipe and 497756 as connector ,rear hose.The 100 is the style with the hollow bolt going thru it.

Thanks Gene. If you click on "More Info" on the FS #SA-305, it says it has the 3/16" opening. If you look at info for SA-306, it says it has the 1/4" opening. So I think The Filling Station has these listed backwards. I've ordered the SA-306, and if it comes with the correct 1/4" opening, I'll give them a call and alert them to the error.

I was just reading it out of their catalog.Its a March 2006 catalog.If they were smart they would send me a new catalog. :)
I do try to send business their way.

Yes, I have bought a lot of parts from The Filling Station, and have been very happy with them. That's why I want to help them correct any errors in their listings so nobody else has the same problem. Curiously, Obsolete Chevrolet parts also has the sizes switched for these brake line blocks, with 3/16" for the earlier models, and 1/4" for the later ones. That's where I bought the wrong sizes that I have. They must be buying from the same supplier.

Finally got the confusion solved with the brake fitting sizes. The Filling Station's SA-305 that is listed for 36-50 Chevys is, in fact, the correct part. They just made an error in the description which says it has a 3/16 inch opening. In fact, for the 1/4 inch line, the threaded hole is 3/8 inch. They're sending out the correct part. Case closed (I think).