I am trying to confirm the air source for the air hose connector located in the fuel/propane bay. In the past when I connect an air hose to the connector I had air pressure. It was not always 90 psi if I hadn't run the engine but I had some pressure. Currently I am not getting any pressure at the connector. I've attached the air system schematic but I am having difficulty in trying to interpret the lines and which way the air is actually traveling. In the air hose source drawing I have drawn some red lines in which I think the air is flowing. Please let me know if this correct or not. Thanks in advance.
You got it right
Asking the obvious,is the engine running when you try and get air?
David,
Note that all the air lines you marked in red (in 2nd expanded image) are downstream of the protection valve on that tank. The protection valve, if functioning correctly, should cut off air flow to those lines when pressure in the tank gets to approximately 60 psi (or below). This is the raison d'être for the protection valve - to hold enough air pressure in the tank so you still have a couple brake applications in the event of a catastrophic air system failure.
See post linked below for more details:
Air Tank Valves R&R (https://www.foreforums.com/index.php?topic=27638.msg226701#msg226701)
Thanks for the quick and informative answers. I started noticing the air line hose connector not working as it had in the past after I had Keith Risch work on the air system. He found the tag air bags connected crosswise among other leaks. Maybe he readjusted the check valves from vertical to horizontal. Guess it's time to put on the coveralls and crawl under to have a look. ;D
Check valves don't care how they are oriented...vertical or horizontal all the same to them.
On our coach I have only found two ways to get pressure on the external air connection. 1) have engine running or, 2) use the Air Tank switch by the driver.