Oil press guage issue

I noticed my old D4 Cat (apx 1954) oil press a couple days ago reading nearly zero at about 60-70% RPM.
when I dropped it to idle it showed maybe 5 lbs.
I think i’ve encountered this at sea or someplace before but can’t recall what is was, but rather than influence your answer I’d like to know if anyone else has encountered this?
I can’t believe the oil press quit so I’ve continued working it, and it is no doubt the original guage which I cracked the glass on with the end of my hammer ‘‘jiggling’’ it… like it doesn’t vibrate enough all ready!
it is of course a ‘analog’ guage.


Cripes jimminee, Just had similar problem over here. Different engine though but still a Cat. 1st Assist tried to give it an adjust while it was running the hotel services. I Utilized the results of that as a Black Out Drill. Up and running fine now. Be prudent with that hammer.

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I have other guages i will put in the hole. i wouldn’t trust that pittsburg stuff as far as you can throw it.

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Fair enough it worked well for me when the sending unit in my truck started acting wonky. Better than swapping parts at least you know you’ve isolated the problem with a fair degree of certainty. I sure as fuck wouldn’t use it in a professional setting, although I do see a fair amount of Pittsburg stuff floating around on these ships lol.

I think it was a Fuel Press guage for fuel xfer bulkhead mounted I finally diagnosed as broken diaphragm but it’s been years ago. This dozer guage is easily accessible and I think i have a few guages around here that’ll take a beating. i’ll swap it out when it quits raining and warms, meanwhile i have about 5 usg of water in the gear boxes from working in water.

UPDATE: I was surprised no one guessed what the issue was. What was happening is the oil filter was clogged. it would show 5psi at idle but at greater speed the oil bypass would open fully and no detectable pressure would read on the guage. I swapped the filter out and the guage went to 30 psi. NOW; what is in the oil filter remains to be seen?

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If your oil filter was clogged you have issues, disassembly - and inspection to determine the cause of failure, extent of damage and the debris in the filter will be required.

I hope for your sake it is blue silicone or cork gasket debris from a previous lubrication system repair - gasket reseal. Please keep the thread updated when you cut the filter to the paper element to see what was / or is in there.

Hopefully it is mud from finding the oil cap open while working in mud as deep as the tracks. I’m doubtfull it will be bright shiny stuff but who knows the winds of fate? Since there is no evidence of water contamination the prospect doesn’t seem ‘‘shiny’’.

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Sending you well wishes. Mud is abrasive. How many times do you plan on changing the oil and filter? Good Luck.

once, when it’s hot but it needs cleaning with fire hose to get to the drain plug and it’s working now a half mile from the shop/wash rack… and the fire pump is in the barn, hasn’t run this year

I had the same problem. I removed the sending unit, cleaned up the threads and that fixed the problem. Unfortunately the gauges in our jeeps are really only good for telling you if there is oil pressure or drill press. They do not read true pressure like a mechanical gauge would.