1872 oil pressure sending unit SNAFU

asmith · Jul 9, 2020

1872 had a major leak in front of engine on right side. Changed the seal and decided to change oil pressure sending unit. Didn't see the reducer under the unit and snapped the brass fitting off at the block. I can't budge the part left in the block with a retractor any suggestions.

jstich · Jul 9, 2020

asmith said:
1872 had a major leak in front of engine on right side. Changed the seal and decided to change oil pressure sending unit. Didn't see the reducer under the unit and snapped the brass fitting off at the block. I can't budge the part left in the block with a retractor any suggestions.

I've had good luck using left hand drill bits for this type of problem.

asmith · Jul 11, 2020

Thanks Jerry, I've been debating that method. Requires removing a few more parts to be able to get at it.

asmith · Jul 12, 2020

Used a left hand drill bit yesterday and it worked like a charm. The fitting backed out with threads intact.

jstich · Jul 12, 2020

asmith said:
Used a left hand drill bit yesterday and it worked like a charm. The fitting backed out with threads intact.

I'm happy hear that it worked for you.

1811Cub · Jul 13, 2020

This happened to me with my 1811. I ended up drilling the hole oversized to accept a 1/8"NPT tap. This made converting to a mechanical oil pressure gauge and retaining the factory warning lamp far easier.

hydroharry · Jul 13, 2020

If you're drilling and tapping how do you keep from getting any shavings into the oil flow channels?

1811Cub · Jul 13, 2020

I coated the drill bit and the tap with grease. This prevented a majority from going into the engine. After I tapped the hole, I cranked the engine over for a few seconds, and the pressurized oil blew out what few shavings made it into the hole. I have several hours of use on it and no issues. The oil pressure is 60 psi cold, and 45-50 hot at WOT with SAE-30 oil.