Common air leak location

Under cab, lines by frame in the cluster of every line on the truck, look under the drivers door at all the lines and figure the one in the middle of your nightmare

 

Check your cab air shocks for small leaks, those can be hard to detect unless you are touching them, but could certainly cause your tanks to drain.

 

Dont know you age, but I am 62 possibly little hard of hearing. I use my grandchildren lol. Spray bottle with soapy water in it. Or a quiet area if you can find one. Every time I listen, a vehicle drives by. Grand kids say..its over here poppy.

 

When I read the title I had to laugh the most common location is at the hole

 

I pull out a yellow valve for my parking brake, and had to change that out once
cause it did the same thing, leaked down overnight.

 

There's probably 10 million miles of air hose.

Air leaks can be anywhere.

I've never had a truck hold air over night. And my last OTR vehicle was a brand new FL truck and Reitnour flatbed trailer.

 

Start at the Air pump fittings with the spray bottle with soapy water, when its all pumped up with air.
That's how I found mine. Found leak in fittings on my '06 SLC500 Mercedes too, save me from being
a parts changer. I was about to buy 2 new rear airbags for two grand. For no reason.

 

A gallon sized hand pump sprayer with dish soap works a lot better than a spray bottle.
If you mentioned what equipment you are running you might get better answers.

 

Airbags and fittings, leveling valve, there's a 45 degree brass fitting on the top of some Eaton transmissions which likes to crap out, ABS valves and relay valves. cab suspension air bags.. it would help to know which system leaks out first.