I guess this may end up being a rather controversial topic, but I really need some input from ALL of you owners of U280, U295 AND U320 owners. While attending the FOT ladies driving school at Nacogdoches this fall, the classroom instruction was to DUMP all the air prior to leveling the coach with the HWH air leveling system. Despite their best efforts to explain why this was a good idea, I'm too far on the downhill side of senility to grasp it. Our local service rep actually had some good reasons NOT to do it.
How many of YOU dump the air before leveling the coach? Why? Yeah, I know it sets lower, but not sure that means a lot to me.
We do not dump. We just level. If we're too high in front and not completely squatted below, we will sometimes lower a little then relevel.
Just doesn't make sense to me to dump all the air out then pump it back up - more wear and tear on the aux compressor and a waste of the desiccant capacity (if your coach is so-equipped). Plus if you happened to be in a site where dumping all the air twisted the chassis, you could pop a windshield and put undue stress on things.
Never dump// Agree with Michelle this is just extra work for the air system. Have known some people who dump to have the coach lower to the ground but I never have dumped my air and I have always been able to level. DAN
BTW, same advice was given at GV two years ago
We don't dump, just level. It's close to the ground to begin with, really no need get it lower.
I have an older coach, but my practice is to let the engine idle for 10 minutes or so to cool off the turbo and let the leveling system get used to not moving. During that time I make sure that I'm really where I want to be and plug in the shore power. Then I have the HWH system level the coach. Once it is done I check the bubble level and tweak as necessary. Here at home the left rear is resting on the tires while the right front is at almost full extension. Dumping everything would just mean the RF would have to be pumped up all over again.
I also lower the coach when parked at home and shut off 12vdc system unless I'm in the coach.
What seems to be the issue here is ---( HWH-- Active Air) -- Active air equipped coaches , hit the auto level button and you drop the coach to the frame , then make's it level automatically. Mine drops with a thud , front and rear then is level fairly quickly . Making sense of this is not in the cards . I would guess that is what the driving school was thinking about . My 2 cents worth . Brad Metzger
David,
There is no need to idle for 10 minutes to "cool the turbo" unless your RV park happens to be at the top of a mountain. A couple minutes of slow driving from an interstate to a park, then within the park to a site will sufficiently cool the turbo.
We never dump then level, just set the brakes and eather auto level or do it manual, then shut the coach off
Good point, Brad. I believe they used new coaches at the driving school, so those would have had Active Air.
We always raise the coach as high as it will go then level. Couple of reasons. I want the gray/black tanks higher than the sewer pvc otherwise it's an uphill battle. If I need to relevel for whatever reason it can be done by letting air out instead of starting the engine to build air. The best reason is it make the coach look bigger. Kinda like puffing your chest out. :)
see ya
ken
I never dump. Doing so would leave my step hitting the ground. After leveling, I might raise or lower the coach to place the step at a more convenient height.
No need to make an ih45 look bigger.
We always level from travel height. This seems to work fine for us.
The advice (to dump before leveling) must only pertain to the newer coaches. The "HWH Air Leveling Systems Textbook" (link below), published 16SEP99, covers leveling system series 500, 600 and 680. Under Leveling Procedures - Automatic Air Leveling (page 26), it says:
"DO NOT dump all the air from the air bags at this time. Allow the system to level the vehicle from travel height."
http://www.hwhcorp.com/ml20635.pdf (http://www.hwhcorp.com/ml20635.pdf)
If the coach is level when I push the button I will dump the air to get it lower.
I don't know why the unihome and unicoach chassis allows the coach to
lower enough to sit on the tires. I have heard that this practice can crack
tile floors, and if you ever try to move the coach before you reach travel
height, bad things can happen. I level from travel height, and never let the
coach sit on the tires.
Makes the steps closer to the ground
I have never heard of coach damage from resting on the tires. The coach is designed to do this. Of course, never move the coach before it reaches ride height.
The Active Air drops the coach to (hard) stops ----not metal striking against metal ---- and does not touch the tires . The coach can be moved when all the way down . Don't know if it could be driven that way as I always let it get to ride height first . While all set up and parked level , and time to go , you would have to be fast to move before it gets to ride height as it does it right now . Takes a bit of getting used to , but I've learned to let it do what it's designed to do . It's going to do it anyway so I try to not screw it up with some stupid input on my part . Brad Metzger
Brad,
During the summer we were at HWH and there was a Foretravel there like yours being worked on. Interesting he was there for the same problem you are reporting here, the hard stop when leveling. HWH told him that was not proper and reset the leveling to a softer setup. I do recall the owner telling me that HWH said it was not properly set up and needed to be adjusted to a comfortable setting. Hope this helps.
Bob
Brett,
The potential for damage has been known around Foretravel for at least fifteen years and it has been discussed on the Foreforum for at least the past four years.
I have personally seen three FT's with delaminated plywood flooring (as a result of resting the coaches on tires for extended periods of time) and have heard tell of others.
Clearly, not all coaches will be the same (length, loading, slightly different geometry in different models) and I don't think it is an issue
after the 2000 model year. I am of the impression that if the coach is on a level surface, it is less likely to do damage than when the coach is not on a level surface and the suspension is "cocked" as the HWH achieves level with one corner's air bag set fully exhausted. I think that may be at least part of the reason why FT added the 10 psig minimums for 2001"s (I think) and newer coaches.
Larger tires - reasons and caveats? (split from Tire clearance issue) (http://www.foreforums.com/index.php?topic=17446.msg116292#msg116292)
Dump or Not? (http://www.foreforums.com/index.php?topic=14319.msg82845#msg82845)
Heed or dismiss, but it is a known issue.
Of course Foretravel is not anxious to say that it is an issue, because repairing and/or replacing sections of the delaminated plywood flooring (in the three coaches that I am familiar with) was both tedious and costly.
Neal
I've been somewhat concerned about this, too, as our coach shows some grooves worn in the skin directly above the tires in all locations. I can't see how those grooves could have gotten there without the coach being driven a fair distance while the body was resting on the tires. That may not have happened all at once, of course, but since the coach was 20 years old when we got it it is possible that one of the two previous owners may have repeatedly tried moving the coach while it was resting on tires.
When we get down to Nac I'll have some of the experts down there take a look and see what they suggest. I'm wondering if a piece of 1/4 inch aluminum plate over each tire (securely mounted to the body, of course) might be a good safety device. Another possibility would be some sort of mechanical stop to make sure that coach and tires can't meet.
I generally level from ride height. Sometimes, if the site is level, I may lower the coach to put the step a bit lower.
We generally don't move the coach until air pressure on both gauges is at least 90 psi. The coach generally moves to full ride height if pressure is at least 85 psi.
When dumping holding tanks, I generally raise the passenger side as high as it will go, lower the driver side, and level the coach front-to-back. Tanks drain well in that attitude. I minimize time in that position to avoid refrigerator (and discomfort) problems.
David, my wheel well had a hole where someone moved the coach while the chassis was touching the tires. It really is no problem other than potential water penetration causing rot of the plywood above so I sealed the penetrations with black urethane caulk, 3M 5200, and 1/32" fiberglass sheet. I don't think it would have been a problem if I didn't do anything but I try to err on the side of caution.
David,
As you can see, when you level the coach and it sits down on the suspension hard stop, the tire will contact the top of the wheel well, the weight is on the hard stop, not the floor of the coach, however when going down the road and you hit a hard dip and you get that loud bang, that's the contact with the hard stop and the tire just touched and you just added to those wheel well skid marks.
They all have them, when they wear through, like Ken you repair it.
JD
I think from a post here that the 99's and up were raised on the chassis so that at full dumped the tires do not touch the floor.
It's not the movement at full dump but the coaches body roll IMO. My marks and worn through skin in the wheel well are deeper at the outside. That's roll.
Shock were way too soft for a long time on mine
This is a thread of certainly some variety of parking level and different understandings and leaves me now uncertain.
We have an 01. If I dump the air, the tires do contact the wheel well, contrary to what another sees or expects in the thread. Perhaps it rubs and does not really rest, but I can say for sure it really seems resting...no, none, space between tire and wheel well.
James Triana told me that it is okay to rest on the tires. He did not say that on the 2000 and later, as in mine, it would rest on some stops. From this thread I am unsure he was right.
I do have some wear on the wheel well and cannot say if a prior owner drove it a bit in air dumped mode, and hence the scrape. I now read the idea in this thread that the scrapes may be from bottoming out when driving. I see no damage or much of an indentation at the scrapes.
I have a friend who puts wood blocks on top of the tires to level and posted that practice on thevForum, wondering if it ok. Some said that seemed a good option as the coaches were made to rest on the tires. From this threaded am concerned that is quite wrong to do, for rather than resting on stops, as some say, it is truly resting the plywood on the tire, which some say herein would be wrong to do. I think that could be so based on the list here about observed impacts of tire to floor.
I agree with the posts that if you are going to rest on the tire, or the stops, it a wise precaution to be on a level surface to avoid possible twisting forces.
It seems a contradiction though if you cannot rest on a tire....fir when I level it there are times the algorithm seems to put the coach on one tire and the other three corners are not.
I seem always learning.
Mike
Does a 1999 U320 40ft have hard stops?
best, paul
Thanks Bob,....I have the original size tires, not moved up to the 295s
Mike
Not the size necessarily as I have no exact info but the diameter may be different on the same size but different model and/or different brands.
Seen it before in the biz
Mike,
I wouldn't worry about twisting the coach during auto leveling. The 10 psi switches that Foretravel (not HWH) installed on the front HWH manifold are there to prevent that. When the first side sits on the hard stop the airpressure in the air bags on that side will go below 10 psi and that 10 psi switch will actuate and remove power from the dump solenoid for the other side to prevent that other side from continuing down and twisting the coach.
Unless you are on level ground where both sides hit the hard stops at the same time you will only have one front tire in contact with the wheel well.
If we put a block of wood on top of the tire, that will become the hard stop and put all the weight at that corner on the floor of the coach. Bad idea!
This is a good system that works. I just push the level button and see if it can level there,if it can't I move a little or put blocks under the low corner and try again.
JD
Bob, we use Michelin. Guess that same as originals.
John, thanks. I do exactly what you wrote last.....pull in, hit level, put out slide and leave it. I have been some places where too much slope and had to put 2X6 boards under the tires, not on top as my friend is doing.
Even so though, I did see it go at times to one corner with tire contacting the wheel well with the top of the tire, and worried (s) me. From what you wrote, I gather that ok on the 2001. Others with earlier models may or may not be able to apply that, reread the thread for other years if question
Thanks again Bob and John.
mike
I changed to 295 tires, when the coach ended up sitting on the hard stops as a result of unlevel spots the larger tire size caused way to much contact with the tire(s) for my comfort level. I simply added additional 1/2" spacers to the hard stops. Works just fine now tires barley resting on the floor at full dump, and have yet to bottom the coach out on the highway.
Kb0zke wrote "I'm wondering if a piece of 1/4 inch aluminum plate over each tire (securely mounted to the body, of course) might be a good safety device." Our coach had severe scarring over the rear wheels - which I didn't know enough to look for at the time we purchased the unit. The wheel well was actually worn completely through. I brought this to the attention of the chassis mechanic who maintains our rig. He attached aluminum plates, strategically placing the fasteners so that the heads wouldn't scar the tires if the tire bottomed out. He said that this was definitely an issue where the previous owner dumped the air and then took off before the coach achieved adequate air pressure to raise to ride height.
I may be out to lunch on this answer but if the previous owner was driving away before air bags raised the coach off tyres there may be a problem with slack adjusters for brakes. I think you need around 60lbs of air to release brakes and by then the bags would be at least 50% inflated. Driving off right away after starting does not happen as I am sure once you turn the key on (and you have air in tanks) the levelling valves react to lift bags if they had been deflated and allowing coach to sit on tyres.
Am I correct-or not as have not tried this before commenting.?
I was thinking that it may have been a case of bad road surfaces, shocks and overweight problems!!
Any comments?
JohnH
My
have air bags don't start filling until my gauge gets to 70lbs. Don't know if this is universal but it is normal for my coach. I suppose I could drive away before the coach is off the tires, if it is setup that low.
Roland
My air pressure stays up for days after the engine is shut off. If I were to start up and drive off right away I think I could do it immediately, in warm weather of course. I know better but I think I could if I wanted to.
As you should not move the coach until you have air pressure and the engine has warmed for a short while this should be a non issue. I will sometimes raise the coach up and then immediately hit the level button. Coach has a greater range to level from. Also gives more privacy as windows are higher up. Disadvantage is front step is higher then. Dog looks at me with his "Now what did you do?" look as he has a bit of trouble getting up.
Keith
My opinion of the coach resting on the tires is that about the same time as that happens, the suspension also contacts a stop, so that most of the weight is still on the suspension and almost none on the tires. My right rear travel height valve failed while I was driving and although a small hole was worn in the thin piece of plastic above the outside tire, no major damage occurred. There is an inch or more of insulating foam above the plastic and then plywood for the floor. It's also possible that a hard bump while driving could cause a skid mark on the plastic above the tire, making it look like someone drove the coach before it reached ride height.