Mini Lathe To Simplify Quick Thread Removal
 

When a friend was investigating a fuel leak located at a fuel injector (IH
diesel truck engine), he discovered a motor monkey had previously
cross-threaded the line nut onto the top of the injector, so he proceeded to
remove the injector (the line nut was good).

He went to a nearby heavy truck dealer and bought a remanufactured injector,
copper crush seal, and O-rings for the fuel return fitting. The reman
injector was only about $46 plus a core charge.

A problem developed, as the bottom portion of the injector separated from
the larger, upper portion.
The part was down in a restricted recess about 2" deep. Since the upper
injector portion had a very coarse thread, but the bottom portion had a very
fine thread, it would be very unlikely that the parts could be reassembled
in the engine.

We speculated that real truck mechanics probably have a special tool with
the proper thread to screw into the lower portion, which could then be
withdrawn with a puller or slide hammer.

The conclusion was to sacrifice the fuctup injector, as it only has a value
of $13 as a core charge when purchasing a remanufactured injector.

Chucked the injector upper portion in the mini lathe 3-jaw and cut away the
coarse thread lickitysplit.. in a shower of hot chips.

We had seen that the bottom portion could've been heavily coated with carbon
and potentially difficult to remove.. but it wasn't.
He ended up with a removal tool for future use, which could be adapted for
slide hammer use if needed to gently "bump out" another part if the problem
arises.

The worst-case of needing to pull a head off will likely cause your trip to
be postponed.

--
WB
..........