I installed a 0-10lb liquid filled pressure gauge about 2 years ago. The instructions said to trim the top of the little rubber nipple off to vent it. The gauge is in the upright position, so the vent is on the top. I was under the assumption that the liquid was a type of oil, but after two years it has seemed to evaporate. I checked the gauge when I noticed it was getting low, and I could not find any leaks. The gauge I bought says it was made in the U.S.A. Without the liquid the gauge sticks at times. I purchased a new one from a different manufacturer. Can I run this without venting the top? The gauge is mounted under the hood. Thanks in advance.
I have never clipped the fill port cover on any fluid filled gauge, be it automotive or industrial, never seemed to be an issue. Might have to do with elevation or barometric pressure changes affecting accuracy but I can't say with certainty since I honestly don't know why they say to vent them.
Most marine grade compasses both large and small are filled with liquid and sealed. I think the liquid might be mineral oil. I’ve had one hand held compass for 40 plus years and is still the same as new. I would think venting the gauge to atmosphere would allow for bacteria growth/algae/whatever eventually making the gauge cloudy or hard to read.
Thanks for the replies. I am going to run it with the gauge sealed. It did not work the other way, so what do I have to lose.
They said the same thing the instructions said which was to cut the top of the rubber nipple off. I did that after it was installed. They also said that the fluid would not evaporate and that I must have had the gauge on an angle, which I did not.
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