Lost all my air pressure overnight?

here is some things I found about air leaks on my truck with a detroit. the leak around the top of the compressor, where the unloader is leaked only whjen truck was running. soaped all my brake chambers 7 20 min later found very small bubbles on 3 of them. 2 brake chambers were new, like 2 weeks new. the one that leaked the least was one of the original ones. it was not leaking around any airl ine, it was the chamber itself. replaced 3 air bags on trailer. one day while raining, & just had steel lifted of trailer, air bags stretcehd, saw bubbles on the 3 new bags, none on the original kinda dry rotted bag. so dont think, just because you replace a part it is good. behind the dash is where I found a lot of little leaks. the dash shakes & there are bookoo's of air lines & fittings. had leak in power diver lock switch. had leak in the in cab 5th wheel release knob. to try & isolate leak I put in a brass line valve at both tanks & other places, would shut one off to see it that made a difference. the best way I know of, or I should say heard of is there is a system that hooks up to your air system & pumps colored fog , smoke into the system, when you see the colored smoke, you see the leak. I have seen this system advertised for sale to truck shops. I dont know myself much more about it, it just sounds like it would be the best solution, providing you can find some one who has one.

one more thing once you find the leak & fix it, another will take it's place.

 

if you got a truck that doesnt leak air thats ok it will be a matter of time when it will be like the rest of the leaky trucks.

 

Ihave a neighbor who has been a trucker for over 20 years. he now works at a local dump truck co & say's all the new trucks leak almost all their air down over night while the 2 older trucks 7 years old hold 75 to 95 % of their air pressure. go figure. one time I replaced one of my air valves on top of from rear the original was metal, the oem from dealer was plastic. the replacement lasted for about 1 year & it leaked. found a local independent truck parts house, they had metal valves. it is still on my truck. no leaks 4 years now. oem is not always quality. just remembered I had a shop put on a new steel braided air line, a big one, going to the air dryer. it leaked right where the end screwed onto the hose. at first I was not going to soap it cause I figurd it was new. new CAN leak.

 

I used to drive an '03 Volvo 670 that had a leak no one could find. That is until I was queued up at a steel plant to load. Had the truck shut off since it was a beautiful day and could hear the faintest of hisses.

Searched around, then climbed underneath. Found the solenoid block that has the horn and other things switched off of it. Gave it a little tap with the palm of my hand, and the leak got worse. Called the company about the leak, they found the closest dealer (a company I first started driving for). Got loaded and on the drive there, the compressor would cut out and within a minute come back on, air up and repeat. By the time I got to the dealer the leak was quite noticeable.

They found a bad solenoid as well as the manifold were bad. There is a plug in the back of it from the molding process. The plug had almost fallen completely out. New manifold and solenoid later and my air horn worked again and the leak was gone.

 

Mayby you pickup a bad trl ,with a bad air leak

 

Just writing this for anyone that may need some ideas. I have a Pete 387. I was losing air overnight, first primary tank for about 2 weeks then both tanks. Was driving me crazy, I could not find it anywhere.

Well one night I parked in Petro Milan NM. It was very quiet and when I shut down I heard a faint hiss. Checked outside, nothing. Came back in and heard the faint hiss.
Turned out to be the 1/4"female to 1/4 " female air coupler under the captains chair. What feeds air to the chair. I couldn't hear it because of the rubber factory carpeting over the insulation. But after I cut away the rubber and insulation, SHSHSHSHSHSHSHSHSHSHSH!!.

Turns out both chairs were leaking. The coupler just went bad I guess, they were original from 2008. I bought the part right there in Petro $13.20 each for what would be $4 anywhere else, (wouldnt be a petro if I didn't cost you 3 times as much). Took about 15 mins to swap them out. Problem cured. I was able to reach under the cab, over the fuel tank to unscrew the nut holding it in.

And Just for info. I at one time also had a fan hub leak. Compressor was cycling every 2:30 seconds while driving. Fan would work great, no issues but when I finally bought a new rebuild kit, (got a gold top), and took the old one apart,(Horton), the bearings came out in pieces. Now with both fixes, (fan and chairs), the truck holds air for about 20 mins without the compressor cycling while Im driving.

Hope this helps.

 

Must be driving on the worlds smoothest roads if it doesn't cycle for 20 minutes.

 

Older the truck is higher the chances are of loosing air overnight. Had a rear axle ballon leak one time,cab ballon, spliter on shifter, any fitting, air tanks.... Leveling valve.

Best places I have found air leak was when I was sleeping up north deep into the Woods. Could hear even the smallest of the air leaks. Its easyer to located the aproximate area in really silent areas. And then you can spray water and look for bubles.

 

Or someone stole it. Silly Question

 

Winter air leaks off faster than summer air-