How To: Ford CMP "Blitz" miscellany

[Jacques Reed]

A bit more miscellany:

A discussion with a fellow member about the hose from the radiator to the overflow tank on our cab 13 Fords got me interested in finding a solution. Any hose, original or even NOS if you can find one, is probably too perished to put into service.

The first thing to determine is what threads are on the tube nuts. Using my thread restoring file as a thread gauge, and taking measurements of the male end of the elbow showed it to be ½-24 TPI with parallel threads. In Machinery’s Handbook ½-24 is listed as a UNS thread (Unified National Special). With the olive on the tube I could reasonably assume it was a compression type fitting. The brass elbow has 1/8 NPT threads into the tank and ½-24 threads to the tube. A rare fitting I would say.

I searched various hose company catalogs to see if Pirtek or Enzed might have any hose ends with those threads but didn’t find any. I then tried hose fitting catalogues. Finding the actual size threads on the compression fitting nuts was not easy. An American company, Dixon Valve, did show their 5/16” tube nuts had ½-24 threads. As always, in Australia sourcing parts from the US can be problematic however.

I revisited an Australian fittings catalog and by chance I saw their 5/16” tube compression nuts were listed with ½-24 threads. Surely then their 5/16” compression fittings would have the same threads. Interestingly, that was the only fitting part in the catalog that specified those threads.

I obtained two 5/16” female joiners and a two barbs to match with 1/8 BSP threads on them. A bit of 5/16” radiator hose completed the connection.
I considered putting OTK type clamps on the hose but I don’t think it is necessary. The hose ends had to be put in hot water to fit onto the barbs with a fair bit of pushing to get them home. After it cooled there was no way I could pull the hose off the barbs.

Also of note is the cab 12 and Cab 13 hose are different based on parts catalogue numbers.

I am sure there are other ways to plumb it in but this works for me as I like to keep as much as possible of the original fitment on my truck.

Thanks, Tony, for the original photo and measurement.

Hope this is of some interest.

Cheers,