Hi there fellow RVers,
I'm trying to get my mother-in-laws 2003 U320 coach to the shop but have run in to some snags getting it off and running.
By the help of this forum, I was able to get the dead batteries recharged and start the coach but have another problem impeding me from departure.
The panel lights"Level System" with a sustained beeping/warning bell are on and the both front and rear tanks remained at 25 psi for more than an hour. Also, the HWH panel remains unlit and the step cover and outside step will not come in.
Any ideas on how to get the tanks up to pressure where I can drive it to the shop?
Thanks,
Michael
Assuming the 25 PSI was with the engine running.
That indicates either a massive air leak (should be able to hear it) or a problem with the air compressor, air governor or air dryer.
If you do not hear an air leak from under the coach or from the air dryer (open engine hatch/back), replacing the air governor is an under $25 and easy to do next step.
Make sure the drain valve for the wet tank is closed. Most often mounted under coach ahead of rear axle driver side.
Exactly! The engine has to be running.
P
Yup, any place large volumes of air can escape will keep PSI from building. But, you should hear that size air leak.
Most likely suspect is the air drier. A search for air drier bypass will probably lead you to the bypass kit and you can air up and drive. It is 3 fittings.
Air Dryer Bypass Demo (https://www.foreforums.com/index.php?topic=22007.0)
Many thanks for the suggestions! Yes, engine was running. I did shut it off to listen for a leak but hear or locate one, although it was pretty windy outside so I might not have been able to hear it.
Upon Doug's suggestion I checked the drain valve and it was closed. Quickly opened and shut it to find a burst of chalky air.
I'll check the air drier next time I'm up there.
Thanks,
Michael
If you had chalky air sounds like a bad air drier.
Chalk/white powder in the wet tank drain says the air dryer has FAILED. The desiccant has disintegrated and has entered the coach's air system.
And, that fine white powder is likely clogging quite a lot of the air valves in the coach. The longer it is operated, the more components likely to have been effected.
$$$$$.
Neglecting to service the air dryers can be VERY expensive.
Thanks Ron and Brett. I'll consider bypassing the air dryer as recommended by Chuck.
Chuck, thanks for the elaborate air dyer bypass demo!
Michael
I would do a search on the forum for air dryer failure and contamination.
Rich
Thanks Rich I'm doing a little homework on that now. This is my mother-in-law's coach and was not expecting to do much work on it myself! Not that I'm particularly shy of it, but it's kind of hard to do coach-specific troubleshooting as I've been driving up from Dallas to Athens. All I really want to do is just get it to the shop for service and maintenance.
My father-in-law who recently passed away took great care of this coach since he bought it from MOT in 2014. He religiously had it serviced it at MOT. I'm hoping the failing air dyer issue hasn't been going on too long as I would suspect either he or MOT would have noticed? That being said, it has been just sitting in storage since March.
I will be up there tomorrow to attempt the bypass in order to get it up for driving. I'll come back and report win or lose. Wish me luck!
Michael,
Couple more things you might try to check before you dive into bypassing the air dryer.
There are at least 3 air tanks on a 2003 U320 - probably 4 tanks if it has a slide. You said you checked the wet tank drain valve and it was closed. There are at least 2 more drain valves (front and rear brake tanks) at the front end of the coach. I'm not sure about the exact location of the drain valves on a 2003. One of the owners of a similar year model may jump in with that info. It would be worthwhile to be sure these other drain valves are fully closed.
Also, if you can locate the air dryer and safely reach it with your hand while the engine is running, you could hold your hand under the exhaust valve on the bottom of the dryer and see if you feel air coming out. If it is stuck open, you would probably
not be able to
hear it leaking over the noise of the engine running, but you might be able to
feel the air blowing out the valve. If you
do feel air blowing out the bottom exhaust port, it wouldn't hurt to try rapping it with a hammer. Sometimes a little "percussive persuasion" is all it takes to free up a sticky valve. If it doesn't work - nothing lost. To do the bypass procedure you are gonna get very well acquainted with the greasy underside of the dryer.
Let us know what you find.
Should be 3 drains in front of drivers side front tire and check second bay behind drivers front tire, that contains your 12 volt compressor for your slide seals.
Hope all had a Happy Thanksgiving holiday.
Not much time for me to do much troubleshooting as the forces of TG were too strong.
Quick Update: I checked the air drier and did not feel any air blowing out of the exhaust port during the run. The 3 drains in front of the driver's front tire and all were closed. Both front and rear tanks were at ~45 psi and held steady for about 30 min of engine run time. Can I rule out the air drier and/or governor based on these observations?
Also, I noticed that the aux compressor in the driver's bay (at least I think it's the aux compressor) was not running even when flipping the Air Tank switch which was lit when in the on position.
Many thanks,
Michael
the air governor was mentioned. sometimes a few good taps with a hammer will
bring it back to life for a short period of time. if you cannot detect air leaks, that
is where i would look first.
Replacing the D2 governor is cheap and simple. Getting the air dryer replaced at any heavy duty truck shop will likely solve most of your problems. This kind of work is well within the skill set of most HD mechanics. You can buy a remanufactured unit, get it installed (should be about an hour's time), get a partial refund for the core of the unit, and I bet by then you will have solved a couple of problems (dessicant escaping to contaminate the whole system, and your low pressure problem).
Replacing the air dryer is also fairly easy DIY, as long as you have the wrenches. You'd likely have to order from NAPA, DA33100X, IIRC for a Haldex-reman'd unit. You'll need to reuse connectors on the current air dryer and it helps to have someone help hold things.
The tough thing might be the contamination through the system from a failed air dryer. That desiccant gets everywhere in the system when the dryer fails. MOT is familiar with cleaning up the system, likely better than using a truck mechanic for that work.
Desiccant in air system (https://www.foreforums.com/index.php?topic=29789.0)
2003 U320 - Phase 2 of Desiccant Powder Cleanup Complete (https://www.foreforums.com/index.php?topic=19850.0)
Air Dryer desiccant contamination creates symptoms of air leak (split from... (https://www.foreforums.com/index.php?topic=17640.0)
Another Haldex air dryer failure (https://www.foreforums.com/index.php?topic=24650.0)
Desiccant powder in air system - anybody else with this experience? (https://www.foreforums.com/index.php?topic=18448.0)
Figure out how to add air into the system. This will tell if you have air to leak . Meaning that if the comprssor is not working , you wont build air .
It will tell if you have a leak in the system or lack air pressure at the engine/dryer system .
Thanks all for the replies!
Ok, based on suggestions I will start with the governor and then try bypassing/replacing the air dryer to see if I can get some pressure built up enough to drive.
Yikes, Michelle! Those links about white desiccant are quite intimidating! I'm not sure I have the savvy to diagnose airlines and check valves. Hopefully, I can get the rig up to MOT and have them assess.
Win or lose, I appreciate all your help!
Michael
Greetings Foretravel Owners and Specialists,
Happy New Year!
I finally made some time to get back up to Athens to try to get my mother-in-law's coach going and report an update.
Update: As suggested, I have by-passed the air dyer by closely following the Dryer Bypass Demo and related posts on this forum. Both tanks are now going up to 130 psi. I am very grateful to have had the wealth of information and guidance of members here to have performed this as I wouldn't have had a clue nor attempted this otherwise.
The step cover and outside sliding step are now working. The awnings are also now working. The coach actually raised. So, I think most of the pressure-related problems have self corrected.
However, I still couldn't get the coach to go into gear. The leveling system light remained lit and alarm kept dinging. The travel mode button would flash intermittently when pushed but go off after a few seconds. The parking brake releases but the 'R' and 'F' just flash when attempting to put the coach into gear.
Eric from MOT suggested that I extend the slides 6" and retract them to reset the sensor, so I plan to do that next time I go out. Thought I might post among the tried-and-true veterans forum though before I go as it's a pretty good drive out there with one solution in mind. Any other ideas would be appreciated.
Also, I ran the engine for a good 30 min or so with the bypass. Is there a good way to purge water from the system? Nacogdoches is about 2 hrs away.
Many thanks,
Michael
Best way to remove the water from the air is to hook up a working air drier.
Easy peasey. don't worry about water accumulation in the air tanks for now. At the end of a full day of driving. open the drain valves on at least the wet tank and allow the air pressure to blow out the water. From there you can judge how much of a problem you have with water accumulation.
Thanks Toolmaker! Hopefully, I'll get to the point of a full days driving!
You're welcome Mlawre, but "hopefully" you'll either drive over to Nacodoches and have that air dryer replaced or hie thee to a NAPA and replace the damn thing yourself. Or order one on-line. I know I have that task coming down the pipe. But I run on "retired" time.
New Years Eve I was contemplating a trip to the town clerk for a tag for my Siata project.
I made a snarky comment about Brad Metzger taking a day off for a chest cold.
That's my picture next to hubris in the dictionary.
Nyquil, Dayquil hot drinks and chicken soup.
"What goes around comes around..."
Aspegers here so compassion is a learned response. As in, if I don't remember to show compassion the Universe slaps me up aside the head until I learn.
Seven sheet metal screws! And then sort out the electrics and I'm done.
Sounds like a fun project! Although having a cold can certainly put a damper on it. Hope you get well soon!
Well, I've crashed a couple of motorcycles, and I'm living with heart failure, so I don't feel guilty kicking back reading cheap dime store mysteries while I nurse this cold. Currently Lee Child's Jack Reacher thrillers. But yeah, I'm kinda Jonesing to take the Siata out on the road.
So. When do you make the drive to Motorhomes of Texas to have that rig of your checked out?
Final Update:
Just to provide closure for some other owner who might run into similar troubleshooting issues...
Summary: The dryer bypass got my coach back up to pressure, but did not allow me to kick put into drive. Tried lots of stuff, including two paid mobile tech trips, both who could not figure it out.
I was just about to have it towed but fortunately I described the problem by phone to Eric at MOT, and he correctly identified the problem. The dinging I was hearing with the key in the ignition was the the HWH sensor warning telling me a slide was not closed. Sure enough, the bedroom closet slide on the passenger side was out about 3/4". I opened it six inches to retract, and voila! The warning bell desisted!
So I brought it into a local shop in Dallas called Blue Moon to have it serviced. Luckily, there was a guy there named JJ who said he was actually on the assembly line when they rolled this U320 out. He said he recognized the coach because there were only two of them made. Supposedly there was an intense discussion on whether or not it was a good idea to put granite countertops in it. Well, I must say, I didn't even know they were granite until he pointed it out!
Anyway, it turned out there was a faulty solenoid that needed to be replaced. After replacing it and rebuilding the air dryer all worked fine.
I must say that I was impressed with how fast they took me in (same day I called) and had all the service work done within a week. Have it back now and order has been restored! Taking it out this weekend with family to attend a tennis tournament and afterward going to visit an alpaca ranch.
Thanks so much for all the troubleshooting ideas and help.
Hopefully one day I'll know enough about this stuff to return the favor.
Cheers,
Michael
Thank you for the final update. It is good to have the follow-up.