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Old 03-17-2022, 01:24 AM
Schurkey Schurkey is offline
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You can bleed the gauge plumbing, but it does NO DAMN GOOD WHATSOEVER. It is not at all like bleeding a brake system. The brake system has the fluid reservoir ABOVE the master cylinder and plumbing; the engine oil pan is below the oil pressure gauge plumbing.

As soon as you shut off the engine, the pressurized oil in the tubing partially drains back to the engine. The engine oil galleries partially drain back to the pan. The oil galleries are then partially-full of oil, with the rest being air. Over time, those partially-drained oil galleries pump air back into the oil pressure gauge tubing.

There is nothing you can do to prevent air getting back into the oil pressure tubing. You'll be bleeding the air out every two weeks on a "daily driver". (That was me, in 1984...after about the third time, I sat down and figured out what was happening. The primary disadvantage of plastic oil-gauge tubing is that you can see the air bubbles.)

And it DOESN'T MATTER, because that gauge reacts to pressurized air approximately as well as pressurized liquid, except with (very) slightly reduced speed. As said, the air does dampen the gauge movement some.


Last edited by Schurkey; 03-17-2022 at 01:35 AM.
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Old 03-19-2022, 11:04 AM
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Any update on this?

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  #23  
Old 03-19-2022, 12:53 PM
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Line kit hasn’t come yet

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  #24  
Old 03-23-2022, 06:50 PM
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Well I got this fixed with a cut to fit copper line kit but I have to say all the other gauges are perfect but I am not happy with the movement of the gauge. It is not smoothing going up and down. It’s jumpy but oh well it works and looks good

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Old 03-23-2022, 07:57 PM
TedRamAirII TedRamAirII is offline
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Quote:
Originally Posted by 64speed View Post
Well I got this fixed with a cut to fit copper line kit but I have to say all the other gauges are perfect but I am not happy with the movement of the gauge. It is not smoothing going up and down. It’s jumpy but oh well it works and looks good
I think I would want that. Sounds more accurate anyhow. You could dampen it with a orifice. I wouldn't touch it, just run with it.

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  #26  
Old 03-23-2022, 08:06 PM
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Is this with the car moving or still? The only time I've had a jumpy needle is when the oil level was low while driving. An open bypass in the oil filter housing will cause the oil pressure to go up slowly as you increase throttle and go back down to almost zero at idle. A restriction will cause a slow gauge reaction.

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  #27  
Old 03-24-2022, 05:43 AM
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Quote:
Originally Posted by TedRamAirII View Post
You could dampen it with a orifice.
There's an orifice built into oil pressure gauges. Built into a lot of gauges. It's there to dampen oscillations and minimize wear on the gauge. Also make it easier to read because it isn't jumping around. Same reason they fill gauges with glycerin. Take the line off of the back of the gauge. Look up inside the fitting. There should be an orifice in there. Check and see if there's a piece of crap stuck in it. I suggested this earlier. I had this exact same thing happen to me 30+ years ago. I poked it with a needle (or something) and it squirted oil out. Worked perfectly after that.

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