I had a Schrader valve go bad in a tractor rear. When I tried to pull the core the wings broke off the top of the valve. "No big deal" I think, "I'll just put in a new body." This is the 2 piece type that allows for loading the tire and uses the TRCH-3 type insert. The valve body didn't want to come out. I assume that was because of corrosion from the tire being laded with calcium chloride. I finally got it out by gripping the outside of the inner tube part with Vice-Grips and using a small set of Channel Locks on the valve body. The threads were pretty mangled looking on the old valve body and I wanted to run a tap in there to clean the female threads up on the tube side of the assembly. I checked the new valve body threads against everything I could find. Even a Starrett thread checker was no help. Grainger had a blurb stating the thread on their valve bodies was .305-32 but my mic says the major thread diameter is almost .375 and the minor diameter didn't look like it was that much smaller. I also found reference to the cap end of the valve being .305-32, so I'm still unsure what thread it is. I finally drove to town, checked with my local auto parts store and they were no help. Went tot he long time Goodyear farm tire dealer and the old gent there said he'd looked into the same thing many, many years back and never found an answer to the question. So on his advice I lubed everything up and, using Vice Grips and a small set of Channel Locks, got it back together. This was not my preferred solution to the problem at all!
Would anyone have an answer to the thread of the 2 piece tractor valve type set up? It doesn't look like a pipe thread and it's a very fine thread in the 28-40 TPI range I'd guess. I thought for sure there'd be a tool like the 4 way valve service tools Milton sells, but no such creature seems to exist!
Would anyone have an answer to the thread of the 2 piece tractor valve type set up? It doesn't look like a pipe thread and it's a very fine thread in the 28-40 TPI range I'd guess. I thought for sure there'd be a tool like the 4 way valve service tools Milton sells, but no such creature seems to exist!