does anyone lose much air if the vehicle sits for a day? been riding my motorcycle lately and my truck had been sitting for almost exactly 24 hours. checked the guage and it was empty. it was at just over 150psi when i looked after i parked it. i’m at a loss because i checked every single fitting after it was full with soapy water and there wasnt a single bubble anywhere including the check valve 
any ideas?
IDK you must have a leak somewhere. I didnt drive my car for a couple (2 or 3) weeks when it was in the shop. and when I got it out It still had pressure.
i take that back the drain was makin some bubbles but i loosened it and re-tightened it and it stopped. now that i think about it, i went through this before i upgraded the air system. maybe its time i give the tank a bath in soapy water see if its got a pinhole
Is it possible the check valve has malfunctioned allowing the air to back up through it?
like i said in my first post i checked that also and it is fine. it did go from a 80 degree day yesterday to a low 30’s night last night and around 30-40 degrees today. wonder if that fast temp changed affected it?
Doubt it, I heard of a guy leaving his truck fully aired up over the whole winter season in storage and it was still aired up when he got it out in the spring. Did you check the line connecting to the horns?
well i did once because in my rush to get it done i didnt get the compression fitting on the pressure side of the valve tight enough. i just ran out and looked, 3 hours ago it was at 175psi, now its a little above 150 :eek: dammit i need my spray bottle!
i mix fabreeze wit some soap and water… not only does it spray alot of bubbles, smells good too! lol
you know you love your train horns when you lay under your truck in the dark in 33 degree weather to fix it lol i think i found it we’ll see in the morning i’m not goin out there again tonight screw that. i rewarded myself by scaring 3 chicks by the local junior college dorm
sorority girls ftmfw. lol University of Kentucky has a street, pretty much a straight stretch with about 8 or so sorority houses. Class change around 12 or 1 oclock and ill get at least 100 or so… good times. 
aw man i wish i had a university in my town most i can get on a warm day is like 10 or 15 if i’m lucky! the mongolian exchange students have the best reactions though i have to say
lol i bet… I got UKs marching band to stop playing once… That was a good one lol I wish I had a PA system
FYI - changes in temperature DEFINITELY affects the standing pressure of a tank.
Its not out of the ordinary to pressurize a tank to 200 PSI early in the day and come back in the heat of the afternoon to a tank that contains 220 PSI.
They key is to pressurize the tank and check it at the same time of day the following day, under the same atmospheric conditions.
i did know about the pressure rising in the heat of the day but this time of the year where i live finding 2 days that are the same is damn near impossible to do lol but as always lance your knowledge on all things pneumatic is appreciated. i think i got it fixed its only lost about 5psi since last night so i can live with that 
oh and when i said fast temp change i meant it affecting the steel of the tank and brass fittings expanding and contracting at different rates.