Removing an oil pressure gauge

   / Removing an oil pressure gauge #1  

puresol

Bronze Member
Joined
Nov 4, 2012
Messages
82
Location
Lavonia, GA
Tractor
Yanmar 1700
Anyone ever have or still have an oil pressure gauge screwed into the side of the motor where the oil switch should be? I do and it is stuck- wont budge. Ive got all my indicator lights up and running, replaced the old temp switch- no problem. I cant for the life of me get the oil pressure gauge out. The sides are a little scuffed-like maybe it was put in with a pipe wrench. Do I dare put a pipe wrench on it? Any one got any ideas?

I changed out the old fuse block with a new one from NAPA- been reading a lot of old post. Thanks for the wiring diagram Winston.
 
   / Removing an oil pressure gauge #2  
Those are 1/8" british pipe threads in your engine. 28 threads per inch. Your gauge has 1/8" national pipe threads. 27 threads per inch. Many have used the npt threads in the engines but common sense would tell us the further you screw the two together the tighter things will get. Pipe threads are tapered therefore causing them to get tighter the further they engage. Here is the fitting to overcome the difference. Yanmar Tractor Parts: OIL PRESSURE GAUGE ADAPTER - NPT TO "YANMAR" THREADS
 
   / Removing an oil pressure gauge
  • Thread Starter
#3  
Those are 1/8" british pipe threads in your engine. 28 threads per inch. Your gauge has 1/8" national pipe threads. 27 threads per inch. Many have used the npt threads in the engines but common sense would tell us the further you screw the two together the tighter things will get. Pipe threads are tapered therefore causing them to get tighter the further they engage. Here is the fitting to overcome the difference. Yanmar Tractor Parts: OIL PRESSURE GAUGE ADAPTER - NPT TO "YANMAR" THREADS[/QUOTE
Im not trying to add the gauge, the gauge is already in the tractor! Im not sure who put in the gauge, but it appears that there is no adapter. I want to remove it and replace with an oil switch from Hoye. The gauge is nice, but I have a hard time operating the tractor and monitoring the gauge with a hoe I duct taped a mirror to.:laughing:
I was thinking about heating it up where it goes into the engine, and trying to apply a little pressure with a pipe wrench. Maybe it will break free and not break. My concerns are- it may ring off (Im not sure how strong it is) or the threads may be messed up, due to the difference in threads.
 
   / Removing an oil pressure gauge #4  
I understand what you are doing. Just trying to point out why it is so tight. If it were mine I would get down on it. If it twists off I would then start the eeze out/drill/tap/etc. route.
 
   / Removing an oil pressure gauge #5  
ahh.. this is in a yannie....

in the dupe thread you made on this I didn't realize it was a yannie we were working on

depending on the oil pressure gaug ematerial.. the threads inthe block may or may not have survived. I'd try the om sender and some aviation gasket sealer...
 
   / Removing an oil pressure gauge
  • Thread Starter
#6  
I got down on it, and it finally came out. Got the om sender in. Thanks for the input.
 
   / Removing an oil pressure gauge #7  
threads look ok? leaks?
 
   / Removing an oil pressure gauge
  • Thread Starter
#8  
threads look ok? leaks?

Yep threads looked ok. I put teflon tape on the switch threads. Put the switch in, turned the key to on, the light came on, but didnt start the tractor. I will start it up Friday. Tonight I am replacing the alternator and voltage regulator.
 
   / Removing an oil pressure gauge #9  
i don't think I'd have used thread tape.. but if the light came on.. you are ok. sender needs ground thru the block.. but if lamp comes on, goes off and no leaks.. that's all that counts at the end of the day.
 
   / Removing an oil pressure gauge #10  
Even with Teflon tape the points of the threads will still cut through and ground it , I would think?
 
 
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