[Ledslinger]

I searched far and wide for the correct wheel cylinder adapter for my 1962 GMC K1000 Suburban. Never found any, but I did find a solution and a quick easy way to make them from an existing and available fitting. This is two threads about it I posted on the 47-66 Chevy truck forum.

I went to Tompkins Industries, a hydraulic hose supplier today, and showed them a sample 1962 GMC K1000 front brake hose fitting and they said they had 729 of them at their Olathe store. I drove across Kansas City to get them and thought I was in luck, but the male part of the fitting was 1/8" NPT pipe thread instead of straight 3/8"-24. The counter guy looked through all types of catalogs to find one, and was looking at ways to use two fittings to adapt it. I didn't want two fittings.

I bought two of the fittings with the male 1/8" NPT and was thinking I'd drill and tap the male end and thread in a section of a 3/8"-24 bolt and silver solder it in. Then I figured out if I removed the threads on the fitting, it would still be thicker than the major diameter of 3/8"-24 threads: .3667. So I will file off the threads on the male portion while spinning in a drill press, and try to run a die down it. I don't have a lathe.

The fitting part number is 6404-04-02. It has correct 7/16"-20 threads on the female end.

My plan to file down the 1/8" NPT steel fitting down to .3667, and thread to 7/16"-20 worked perfect. I cut the head off a 7/16"-20 bolt to screw into the fitting and chucked the non threaded bolt shank into the drill chuck. Laid my small drill press on its side to do the filing, then stood it up and spun it by hand in the die and stock laid on the drill press table.

Some have solved the problem by tapping the wheel cylinder to 7/16"-20 and using no adapter, but I wanted to keep the original setup with the adapter. Nobody cares about this unless you still have drum brakes on a 1960-1963 or so GMC K1000 or K10, but I have seen several discussions in the past seeking this fitting.