I recently bought a 95 HDJ80 VX diesel 5-speed. It needs many things addressed, but a priority is the heater/defrost. It came out of Nicaragua, so a heater was not critical. I was not getting any heat, so I backflushed the heater core. Still no heat so I used a digital thermometer gun to investigate. Diagnostics showed there was no water getting thru the water bypass pipe at the block, so I removed the hose and found someone had filled the pipe with some form of sealant. It is really well sealed...see photo. I have the $13 part number (16278-17010) and my question to everyone is how to remove this fitting without pulling the engine. Can it be done in place? Or, as an alternative, can I get hot coolant from another source and run a hose to the heater valve? There is a hose coming out of the block that appears could be cut and a T installed. Is this viable or is it folly? It would be a bit Frankenstein, but heat is important here in Nebraska this time of year; without defrost it is hard to see.