Found out tonight that the external air hose connection for filling tires etc, is branched off of the front air bag piping system and has a check valve. You can't use it to back feed and bring the entire coach air system up to pressure. Was hopeful I could use shop air to bring the air systems up to pressure, fire the engine and drive immediately out of the coach house. Will have to add a valved connection in the engine bay.
If you have a remote drain valve on your wet tank, you could tap into that line. It should feed directly back into the wet tank and at least on our coach does not have a check valve.
I don't have remote drains but that is a easy place to tie into, and I could replace the drain valves at the same time.
That practice will add moisture to your air system-OK for an emergency, but not recommended as a common way to start your day.
I can add a dessicant cartridge (capped when not in use) to a hose whip.
I'm not sure that I understand why. It is good to run the engine to warm it up and get things well oiled before loading it up. This allows time to get air pressure up also. I open all the doors and windows in my RV garage before starting the coach and let the exhaust vent freely. It is some what of a concern in an RV park, but I don't start up in the middle of the night or early mornings and don't see that bothering my neighbors with a little run time is a problem. Exhaust can some times be bad depending on wind and parking arrangements, but is it worth defeating a well designed air system?? Just things to consider ---- Have a great day ---- Fritz
OR, rig up a flexible exhaust tube that vents coach exhaust to the outside of the coach barn. Several Forum members have mentioned using this type device with good results.
I was also hoping that I could add pressure to the tire line and power up system air. The front bags are in their own check valved part of the system, but I was not aware that the tire hose ran from this. Thanks. I will find a workaround.
If your D-2 governor is in a handy location in your engine compartment, that is another point that ties directly to the wet tank. There should be a unused port marked RES with a pipe plug in it. That is where I hooked up my wet tank air pressure gauge.
The d2 is probably a good as place as any, pipe threads if I recall. It would be real nice to air up the whole system for various reasons in the coach house, would make it easy to check for leaks, and other maintenance items also. I can get ahold of a refrigerated air dryer for free easy enough as we remove 4 or 5 of these a year during building remodels where pnuematic temperature controls are modernized. Throw the compressors away also but there just really low pressure 60 psi or less single stage units with 3 phase power.