Maintenance Questions

[scfishnman]

1. Is there a way to drain the air tanks. If so, how and how often.
2. The manuals that came with my coach are conflicting as to chassis & drive train maintenance. The Cummins manuals have long lists of things to do every 6 months. What services do you do and how frequently.
3. Does DEF only have an 18 month shelf life as claimed in one of the manuals.

Sorry for all of these questions. This is my first diesel other than one in a car, and it did not require so much service and so frequently.

[formerFR]

- the tanks generally have 'pull cords' within each front wheel well - probably two on the driver side, and one on the passenger. I've pulled my several times over the 5 years we've owned it and traveled over 100,000 miles, but I've yet to ever see any water, which is the main reason to pull them. I also realized that these tanks usually already have an 'automatic' drain, which pops off when the tanks reach air capacity anyway.

- I'm sure there might be some maintenance things to have on a list every year, and your Cummins Engine manual will give you the best ideas, as the Freightliner chassis will be more for the chassis itself, which more relates to suspension, greasing, and braking, etc.
The engine will usually want a good oil change at 15,000 miles, or once every year or 18 months if you don't drive it as much, but I also suppose that changing the oil is not as worrisome as you might expect. Diesel oil has a much longer usable life than typical gas engine oils. It's probably not as critical to worry about doing anything 'every 6 months' just because you own a diesel pusher, but more in relation to how long and how often you are using it. If it's parked over the winter, I wouldn't necessary include that timeframe in my calculations.

-DEF is generally a fairly stable, mostly water, fluid. If it gets air, it will dry out, but even if the def dries out within the tank, the tank has a built-in heater system that is designed exactly for that reason - to reconstitute any dried liquid. If the DEF is already in your tank, then I wouldn't worry about it. Mine has sat for months and months and the engine still cranks will no problems, and I just drive on till I need more DEF.
I've had the engine light come on a few times, and 'outline' of an engine, but this alert is typically only related to the exhaust/DEF system, NOT the engine. It just means that you may have low DEF, the sensors aren't reading the def accurately, or even one of your NoX sensors have an issue, but generally it is NOT going to present any problem to continue to drive, even for many thousands of miles, before you might get a dealer or shop to look at it, especially if you can have Cummins do it. You may even find that the light goes away on it's own after some time of driving, or after your next DEF fill.
As for the 'shelf life', I wouldn't necessarily be concerned about that either, as it's mostly water anyway. Unless you are just hoarding DEF, and don't use it very often, then what you find on the shelf at W*Mt or most anyplace is going to be just fine. Don't fret it.

[SlowrideHD]

Heaters in DEF tanks do not reconstitute dried out DEF. They are in place to thaw the fluid which will begin to freeze around 12 F. The 32.5% urea mix ensures the water and urea freeze and thaw at the same temperature so that the mix percentage does not change during this process.
Cummins recommends that certified DEF that is stored at normal temperatures will have a shelf life of one year. The shelf life is directly related to storage temperature and also affected by exposure to light. Under optimum storage conditions shelf life may extend to two years. Exceeding shelf life recommendations may result in a degradation of the DEF and it may not perform as your emission system is designed.