How often to drain air tanks on diesel?

The friendliest place on the web for anyone with an RV or an interest in RVing!
If you have answers, please help by responding to the unanswered posts.
See posts with no answers
CP

CP

Well-known member
Joined
Jan 12, 2012
Posts
131
Hi all,
I have a 2017 Newmar Ventana LE 3709 class A diesel MH on a Freightliner chassis. One of the things I find confusing is if and when should I drain the air tanks? I see on maintenance list every 6 months, I read places that say every time you use the MH, and when I spoke to freighliner they said i shouldn't need to do anything for up to 3 years or so.
I know my MH is considered an entrance level diesel but does that change when or if to drain air tanks?

Really appreciate your thoughts.
Thanks
CP
 
Usually you can pull the lanyard for the air tanks to drain any moisture that gets past the air dryer.  That is a simple 10 second procedure. As for a complete drain of the air tanks, follow what ever the maintenance schedule calls for. 

There are 3 lanyards on a Freightliner, I believe 2 on the pass side, one on the drivers side.  Use the awning rod to hook the lanyard to pull them. 
 
Thanks SargeW! Appreciate your help.
 
Monaco chose to not install lanyards on our air tanks, and it requires me to crawl under the coach and manually turn the drain valves. As the years go by, it gets tougher for me to fit under the coach, and I must admit that I don't drain water/moisture from the air tanks as often as I should  :-[
 
Modern air systems include an air dryer, essentially a desiccant cartridge that pulls the moisture from the air as it exits the compressor. If you keep the air dryer properly maintained (replace every 24-36 months), you should never have any water in the air tanks to drain away. That's the basis for what Freightliner told you. Of course, you have to pull the drain plug lever once in awhile to know that.

With the low miles that most motorhomes travel, an air dryer rated for 36 month between changes should be entirely reliable over that span of time.

Back in the day before reliable air dryers were standard, draining the air tanks was an every travel day chore for truck drivers, and that gives rise to some of the tales you read on the internet or from old diesel techs. They will still say "better safe than sorry", knowing full well that amateur drivers probably won't keep the air system maintenance up. But if a guy won't change an air dryer cartridge once in awhile, is he really going to fiddle with drain lanyards every trip?
 
I change the dryer cartridge every year before heading south, only about $45. The drain valves are same door as battery switches so I check frequently. Never seen a drop of water in last four years.
 
Tom, that is what the jacks are for, so us full figure guys can fit underneath our coachs. My Hoiday Rambler never had any lanyards to pull as well.


Bill
 
Bill, don't want to scare you, but some years ago one of our members was killed when his jacks unexpectedly retracted.
 
Thanks everybody! I always appreciate the help found on this forum.
Safe travels to all.
Chuck
 
Tom said:
Monaco chose to not install lanyards on our air tanks, and it requires me to crawl under the coach and manually turn the drain valves. As the years go by, it gets tougher for me to fit under the coach, and I must admit that I don't drain water/moisture from the air tanks as often as I should  :-[
Click to expand...
Tom, you can change the drain valves to valves with wire lanyards.
I actually carry 2 spare valves in an emergency kit a mechanic buddy made up for me.

Bob
 
I usually check 'em in the spring and have never had a drop, in 10 years... not sure why to continue?  I guess Cummins must change the cartridge during the annual?
 
... you can change the drain valves to valves with wire lanyards.
Click to expand...

Good suggestion Bob. Why didn't I think of that  ???
 
I had to change the valves in my '04 Freightliner chassis. It seems that FCCC used the lanyard valves with the solid axle front ends but not with the ZF IFS, which presented problems in routing the lanyards to the wheel well. Several years after the chassis was built, a tech at the FCCC factory service center said they had a way to install lanyards, so I had them do the upgrade. Frankly, it still wasn't very practical, but at least I had a way to do it without getting the coach on a lift.

In any case, I never had a drop of moisture to drain once I learned about changing the air dryer cartridge every 36 months. My air dryer was a lot more than Jsplaine's $45, more like $95 plus another $100 labor. Some of the dryer cartridges are not so easy to get at or change.
 
You must log in or register to reply here.

Latest posts

Members online

Total: 1,547 (members: 27, guests: 1,520)

Forum statistics

Threads
131,975
Posts
1,388,539
Members
137,724
Latest member
emorrison
Back
Top Bottom