Attention: TDR Forum Junkies 
Has anyone else out there had their oil pressure sending unit fail? This is what I learned and what I have done to not be caught in the middle of no where with oil running out of my engine.
On the way to May Madness in the mountains of Oregon my oil pressure gauge dropped to zero. Didn't freeze up or start knocking (no louder than usual) so I determined that it was the pressure-sending unit. I can live without that for awhile, anyway till I get to Pahramph and buy a new one.
A few miles North of Tonapah, Nv. oil started leaking out of engine. I lost a gallon before we caught it. The failed pressure switch failed just a little bit more by rupturing the internal diaphragm and letting oil out through the wire plug.
I was in luck, there was a NAPA parts store in Tonapah. They also had the pressure switch for around $28, NAPA part # OP 6670. To change the switch you have to have a very deep 1-1/16" socket. I was in luck again; they had one for about $10. It is part # KD3458. This is the size that fits my ’96, other years may be different.
Now for you adventuresome guys out there like Earthromer, I would suggest that you carry a little insurance in your toolbox. You don't need to buy a new socket or sending unit. This one may have been one in 500,000, but it can ruin your day if it takes your engine out. If you have access to a lathe just hog out the inside of a 1-1/16" deep socket to the depth of 2-3/4". This will allow it to fit over the long sending unit, or you can spend the ten bucks for a new socket at NAPA.
Now you have the sending unit out all you need is a 1/8" NPT pipe plug to plug the hole. This will now keep the oil inside your engine where it belongs till you can get a new unit.
The location is under the injector pump, and not real handy so I made up my spare pipe plug with a two-inch long nipple with a coupling and the plug screwed together. I filed the square end of the plug till a small socket will fit to help install it.
Sorry for the long post, but if it keeps one of you out of trouble it is worth the long read, but you have to do your part by making up your little insurance kit.
On the way to May Madness in the mountains of Oregon my oil pressure gauge dropped to zero. Didn't freeze up or start knocking (no louder than usual) so I determined that it was the pressure-sending unit. I can live without that for awhile, anyway till I get to Pahramph and buy a new one.
A few miles North of Tonapah, Nv. oil started leaking out of engine. I lost a gallon before we caught it. The failed pressure switch failed just a little bit more by rupturing the internal diaphragm and letting oil out through the wire plug.
I was in luck, there was a NAPA parts store in Tonapah. They also had the pressure switch for around $28, NAPA part # OP 6670. To change the switch you have to have a very deep 1-1/16" socket. I was in luck again; they had one for about $10. It is part # KD3458. This is the size that fits my ’96, other years may be different.
Now for you adventuresome guys out there like Earthromer, I would suggest that you carry a little insurance in your toolbox. You don't need to buy a new socket or sending unit. This one may have been one in 500,000, but it can ruin your day if it takes your engine out. If you have access to a lathe just hog out the inside of a 1-1/16" deep socket to the depth of 2-3/4". This will allow it to fit over the long sending unit, or you can spend the ten bucks for a new socket at NAPA.
Now you have the sending unit out all you need is a 1/8" NPT pipe plug to plug the hole. This will now keep the oil inside your engine where it belongs till you can get a new unit.
The location is under the injector pump, and not real handy so I made up my spare pipe plug with a two-inch long nipple with a coupling and the plug screwed together. I filed the square end of the plug till a small socket will fit to help install it.
Sorry for the long post, but if it keeps one of you out of trouble it is worth the long read, but you have to do your part by making up your little insurance kit.
