Air Compressor Leak Down Rates - 8psi per day

Wondering what y’all think about air compressor leak down rates. Last week I added in about 40’ of 1/2" copper to my new air system and Quincy QT-54. I’m very happy with it, but I’ve been collecting some data on how fast the system ‘leaks down’ or loses pressure. Seems I’m losing about 8-10psi per day from 175psi. One side of me says that’s fine, but my OCD side has been putting leak detector on every joint and making sure everything is solid chasing the goal of zero leak down.

I’ve only ever had a small 33 gal portable oil-less compressor before, so I don’t really have a baseline of what I should be seeing on this. I’m thinking some is normal, but how much?
I’m just a home garage shop, so it’s not really an energy loss issue, but I’d still like to learn.
Appreciate any thoughts and/or info…

I think you have too much time on your hands!


Only when I’m not busy.

I shut my compressor off every night and turn it back on it the morning. It don’t get turned on unless its needed. One of the places I worked left the compressors on all the time. One weekend a air line broke and run till it caught fire and burned the place down.


I have an automatic shut off valve on mine. Every day at 6:15PM the rest of the air supply path is shut off, only the main feed from the compressor to that valve is pressured. However, @mechanic416, you do have a good point, shutting off power to the compressor is safer. Hmmmmm.

D**n you, @James5!

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Note to self: turn compressor off when not using it. Got it. :+1: I guess I was worried about the wrong problem :thinking::smiley:

Yes, like I said in the other post when my compressor broke a reed vale it run till it kicked out the overload then the breaker. I was lucky because I was not at home at the time.

My 60gal Campbell-Hausfeld compressor is hooked up to a 230v contactor that’s on my smart-home automation system. If on, the contactor drops out at midnight. I can drop the contactor also by voice command “Alexa, turn off compressor” and from my phone.

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My wife used to be programed like that. Now somehow it got reversed on me.

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Your compressor should have a shut off valve right at the tank, close it when you leave the shop, open it before you start. Shutting the power off is a good thing but you will loose the compressed air you paid to build up.


My system has been in place for about 3 years and no leaks. It can sit for a week at 100 psi without moving the tank pressure gauge. I have a Quincy QT5 and about 200 feet of 3/4″ RapidAir Maxline piping. The trick to the MaxLine piping was to cut it square, use the end beveling tool every time, use a liquid pipe sealant and Teflon tape. When I first installed it I had to redo a couple fittings that I either didn’t cut square or bevel the end properly.

Even though it’s been great I also flip the breaker when we go out of town on vacation.

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Yep - got one of those. I put another a little further down stream that’s easier for me to get to.

Interesting - thanks for info…I’ve been using the pink tape (thick heavy duty) and Rectorseal T + 2 thread sealant. I can’t find any leaks, but obviously I have a slow one somewhere. I’m going to have to go over it all again to see if I can find it. I suspect it’s in one of the unions, but can’t detect it yet. I’m taking the advice of shutting down the circuit when not in use, regardless.