Lost all my air pressure overnight?

It actually holds longer, but I posted 20 because I knew someone like you would say something like you did.

I will make a video and post all 20 + minutes on my next run, just for you.

It really amazes me, really, whats so hard to believe? And on top of that, who cares?

 

Different trucks have different time delays to suspension actuation. There is a fluid damper in the valve, if the fluid is gone it'll attempt to adjust for every little bump.

 

Anything can come on at any moment but did you swap a trailer today? If yes, start there.

I went to school that had ancient trucks and trailers. Got a flat tire hissing away in the AM. But never thought to really look at the tire at the time... But modern tires do have air hoses on em full time these days, so found debris in tire.

 

A closed air system should not leak. The leaks that empty your tanks overnight cost money while you drive because the compressor must feed them all the time. It is very easy to find leaks using an ultrasonic leak detector from a distance. The best instrument is one made in the USA in Denver CO by PlantScan, the PS-ign Hybrid
You can see it here PS-ign Hybrid - Ultrasonic Leak Detector
You can use a special discount coupon (pk12) they give to schools to buy it, you will be amazed what this device can do.
BTW
A leak from a small hole, only 1/64” in diameter flows approximately 0.4 CFM at 90 PSI, needs 0.157 hp, so for a truck running 5000 hours per year it consumes 15.45 gallons of diesel fuel. At $3/gal this costs $46.35/year.
How many 1/64” leaks do you have and how many do the trailers you hook up?

 

A closed air system should not leak. The leaks that empty your tanks overnight cost money while you drive because the compressor must feed them all the time. It is very easy to find leaks using an ultrasonic leak detector from a distance. The best instrument is one made in the USA in Denver CO by PlantScan, the PS-ign Hybrid
You can see it here PS-ign Hybrid - Ultrasonic Leak Detector
You can use a special discount coupon (pk12) they give to schools to buy it, you will be amazed what this device can do.
BTW
A leak from a small hole, only 1/64” in diameter flows approximately 0.4 CFM at 90 PSI, needs 0.157 hp, so for a truck running 5000 hours per year it consumes 15.45 gallons of diesel fuel. At $3/gal this costs $46.35/year.
How many 1/64” leaks do you have and how many do the trailers you hook up?

 

Soap and spray bottle is cheaper...

 

YUP

 

Nice to hear others having an air leak issue / Have a 2004 Volvo 780 and have been replacing all the push on fittings / With the brass compressed type fittings / Just finished redoing all the air tank fittings / Had to redrill and retap every main hole to pipe thread / Except the drain #### fitting holes / Will re do every fitting that I can get at cause those push on ones should be outlawed / If anyone has some helpful hints for me , please send them / The air pressure goes down to the 60 lbs line / Right at the red area / Plan on checking everything under the dash / Got a gallon of Sherloc bubble up stuff to try out / Will try it out on everything that I can see / Hopefully will find the problem leaks / Please send any comments / Need all the help I can get ?????????????

 

Do you have an Ishift or manual?

 

Also pressure protection valve leaks...it is mounted on the INSIDE of the drivers side frame rail....It looks like a spider with about 8 connections...its about 120 it has to be replaced even if just one connection leaks..mounted with one bolt..

Also airbags leak at the fold so very hard to detect..a pain in the butt..
The connections to the airbags(cab and suspension) on top of them also leak...

The leveling valve for the CAB/ suspension airbags leaks..

If you have an ishift, there is an air hose that goes to the drivers side front corner of the transmission..that goes into a 45 brass fitting...that leaks..ive changed that about 5 times already and carry spares..

If you have an ishift, there is an air tank under passenger that has a pressure protection valve on it and another elbow fitting...it feeds the transmission...that valve leaks..i carry a spare..

Over that tank is another valve mountrd to passenger inside frame..looks like a mini airdyrer...that has i think 2 connections...they leak too..ive changed them out..

Then in engine bay..against the firewall where the drivers feet are, there is a PASS through valve...has about 6 connections to it...that leaks..on BOTH sides..so you have to undo drivers side paneling under and behind steering column..sucks..

All the hoses against the firewall and under the fifth wheel..

And of course the dash valve for your brakes, only way to check is undoing parts of dash..there is a video on YT...

Cant think of anything else now..