[Dick]

Almost never. Unless you are stuck in snow and need added traction, or you need to reduce the turn radius and get absolutely every single inch you need.

I will get some flak for saying the above but when you lift the tag it is almost always for a momentary event such as a very very very tight turn, and as soon as you do the tail of the coach drops until the drive axle air bags can get enough air to bring the tail back up. Your 40 footer will eventually get back to ride height with the tag lifted but it takes a long time so if you really need to lift the tag keep in mind the tail will drop so be aware of if anything needs the clearance.

Some early model 45 foot coaches automatically exhausted air from the tags in very sharp turns, a feature later done away with. Some of the early models had a system that used “stabilizators” which were hydraulic cylinders to keep the rear of the coach from dropping. Those coaches can be identified with a microswitch and a cam visible with the front bumper dropped at the steering column. Those with the stabilizators had two cylinders inboard from the shocks on the drive axle.

[glen]

Hi Jon and thanks. Regarding dumping the air I was speaking from the “air bag leveling” standpoint not the Tag axle. I’ve read posts on the plastic coach forums about dumping air, I believe to drop the coach for whatever reason. But I don’t even see a place to dump air in my cockpit?

Harry

[Archived]

You leveling switch to your left that has right ,left, front toggle. Up and down push button. Key has to be on or running. You will hear the air if your converter hasn’t redone it. Mine hadn’t. All behind your shift pad if like my 1991 XL Mirage

[glen]

There is no issue letting your coach all the way down if that is what you want to do to level it or make it easier to get into.

Your coach has a level low system just for that purpose.

[Reagan]

FYI – Prevost in the past discouraged dumping all air allowing the bags to rest on the internal stops for long periods of time.

[Harry]

Harry:

When parking, I usually “drop the coach”, “dump air”, or however you might describe it by switching from “ROAD” to “AUTO” while the engine is running. I hear a tremendous rushing of air and the coach slowly settles down close to the road. I don’t know what the coach “sits” on. Maybe when I drop it all the way its sitting on the bags which Prevost cautions against as was pointed out above.

Now that you have the coach all the way down, go out and look under the coach, look above and around the tires. You should notice that if you had been under the coach when it came down its likely you’d be dead, crushed to death. Had you been reaching around or on top of a tire, your arm would have been crushed.

DO NOT EVER REACH UNDER, CRAWL UNDER, OR GET UNDER YOUR COACH UNLESS IT IS PROPERLY SUPPORTED AT THE PREVOST INSTALLED JACKING POINTS.

If you had the waste tank dump hose connected, would it have survived? Or would it have survived. Keep in mind that when you’re parking on anything other than concrete, (1) the surface WILL NOT be level (the waste hose connection might be at a high spot of that surface) and (2) the coach will “settle” into the grass, gravel, dirt, and sometimes poorly laid blacktop with an end result of the waste hose elbow contacting the parking surface. Will only the elbow break off? Or will the force of the coach break the connection off between the tank and shutoff valve? If the latter happens, you will experience what is known as “spontaneous, uncontrolled waste tank discharge”.

I recommend that you “test” the tag lift fuction on your coach. You will need an assistant in the driver’s seat to do this. With the coach running, level low system in “Ride” setting, the coach at full ride height, have the assistant “lift the tag” while you are standing next to the rear axles. Watch and listen to what happens. You should hear air being released from the tag axles air bags, the tag lift chambers fill with air, the coach should start to drop, air will be introduced into the drive axles bags to bring the coach back to ride height, and possibly you’ll see the tag tires come off the ground. Eventually the coach will come back up to ride height. (The coach might need to be in gear, the parking brake might need to be released. Make sure your assistant understands how to do all of this AND hold his or her foot on the service brake pedal so the coach doesn’t move around.)

With a coach of your vintage, don’t be surprised if the tag tires don’t come off the ground. The pivot point for the arm that lifts the tag axles might be corroded up and frozen. While the tires won’t come off the ground, the weight of tne coach has been taken off the tag tires. One of my pivot points is frozen up. Prevost tech (and maybe Jeff Rowe) told me this is not uncommon when the coach is serviced by someone who doesn’t know that there is a Zerk fitting that needs to be greased at that pivot point.

Once you have seen this all happen, have your assistant switch “lift the tag” off. Watch and understand what is happening. You might need to go through this process a few times to fully understand what is going on.

Had I understood all the stuff that goes on when you “lift the tag” … I would not have dragged the driveshaft loop on our driveway, bending it back, with a coach load of people.

Finally, once you’re going to drive straight at more than 5mph, turn OFF the “lift the tag” feature.

I hope this helps you with your new coach.

[Archived]

Dick, If your coach drops when you put it in the auto position something is wrong. Also, try to keep in mind that what Harry has as far as leveling system controls is not likely to be the same as your Liberty.

[Archived]

HJ,

Use Manual mode on Your level low controls to dump air. Middle position of the three way switch. Road/Manual/Auto. After You have that switch in manual, There is another switch for front, Which You can lower with and hear the air dump from the bags. You can also use this to raise the coach when needed to go over a high spot if the level low is working properly.

Safe travels,

Rocky

[Archived]

Harry, Here is some free advice because I do not hitnk you got the training you expected or deserved from the seller of the coach based on some of your posts.

We who have had a lot of experience with coaches realize when we see questions similar to those you are asking that we have gained a lot of understanding, some the hard way, some by using the coach and some just by taking the time to learn the coach.

What I suggest is you start spending time with the coach. Sit in the driver’s seat and start looking at all that is there and learning what each button or dial does, and verify it does as you think it does. If something puzzles you ask questions. When you get answers always keep in mind you may not get correct answers because even long term owners don’t understand some things because the coach is so complicated and all our coaches go through design updates few of us can keep track of them.

But don’t let that stop questions because every one of us learns when other members ask questions.

When you think you know how to read all your gauges and what they tell you and you know what each knob, dial or switch button does move on to another area of the coach and just try to understand what you are seeing. Our coaches always have a great deal of logic in the systems and how things are put together and once you have a basic understanding you begin to realize you are not an owner of a very complex big, coach but you do own an assembly of components and systems that happen to be going down the road together sharing the same space.

If you have owner’s manuals or operating instructions for the coach or its devices they are going to help you a lot. Don’t waste your time trying to memorize everything, but do keep in mind how to access not only the information you already have, but stuff on line.

[Harry]

Rocky, like I mentioned to Dick, Harry’s leveling system controls are not like your Liberty controls.

[Archived]

Thanks for all the great information guys but I’m confused.

1. When I’m going to be parked for a few days or a few weeks do I have to do anything with the airbags? Or like Brandon said “just leave the coach, you don’t have to do anything with the air in the coach”!

2. Do I really have to do anything with the Tag? There is a RV park here when you pull in says “raise your tag”. I don’t know why I’m only telling you what it says.

I understand leveling the coach at the campground, I’m talking about what I do with the coach when I’m leaving it for awhile. Like when I leave it at my parking place?

Thanks guys,

Harry

[Archived]

When you park you coach there is no right or wrong way. If you want to leave it at the driving height or raise it or lower it it makes no difference. Over time all of our coaches get the leans. When air leaks from the suspension the coach leans to that direction or if it is all the air leaking it settles down. So don’t spend a lot of time worrying about where the suspension height is when you park it. Leave it where it is, or put the height where it works best for you. We drop ours all the way down while we are loading or unloading because otherwise the first step is too high.

Even worse, I back it into the garage with the coach down as low as it would go due to clearance issues and in 10 years I have never seen any ill effects on any part of the coach or its air bags when I did that.

I have no clue why any campground wants you to lift the tag, and have never ever seen a sign saying to do that but I have been doing this for 27 years so maybe I missed it.

[Reagan]

I want to add to the previous post because you need to learn this.

Our level low suspension system allows us to adjust our height by inflating or exhausting air from the air bags such as to level the coach in a campground. We have about 4″ we can go up or down to accomplish that and we all have been in sites where one side is all the way down, while the other is all the way up and the front may be up while the back is down or any combination needed so the coach is level.

Do not only think of that feature as something only for leveling. When driving you are going to encounter conditions that will cause the front, rear or belly to drag and when you see those conditions stop and raise or lower the coach where and how necessary to provide clearance. As an example, a high crowned set of railroad tracks can hang the coach up in the center, or you can anticipate the need for additional clearance by raising the front and rear all the way up to provide the greatest ground clearance under the belly of the coach.

When entering or exiting a steep driveway it is possible to drag the front or rear so that might be a situation when you should raise the front or rear so you do not drag. If you ever have to get hauled on a low boy you may have to raise the coach to avoid damage to the sheet metal under the front bumper. If you are coming off a steep driveway you might want to raise the rear to avoid dragging the engine cradle or hitch.

From this you can see there are times when you will actually be moving when the coach is all the way up or down so don’t fear the need to raise or lower the bus when needed with the only exception being when at highway speeds you must be in the road or driving position.

[Reagan]

Thank you Jon and I think I get all of that! But when I get in the coach and warm it up for 10 minutes before starting off. Doesn’t the coach, by itself, air up to the drive position? It was my understanding it does! So if that’s the case, are you saying that I can manually air the coach up higher from the drive position?

I don’t mean to drive you all crazy with this but I’m desperately trying to understand!

[Harry]

Harry…

Congrats on your coach…you’re gonna find it a labor of love once you get your feet on the ground. Enjoy the journey…

As as to your question about raising the tag & a campground with a sign instructing you to “raise your tag”…First off, I very, very seldomly raise ours. I will, on occasion, if the campground we’re in has very sharp, hard to maneuver turns, but generally, we try hard to avoid those places anyway. You, being 40′, should not have a problem just leaving the tag down and that also allows you to more fully concentrate on driving the bus and insuring adequate clearances all around without the potential additional distraction of dealing with raising and lowering the tag.

The sign at the campground you mentioned may have to do with the surface paving of the streets & sites within the campground itself. If the road surfaces are what we in TN call “chip and tar” (basicly pea gravel with an overlay of tar with perhaps another layer of pea gravel), and the weather is warm, they may feel that the stress between the drive wheels and tags causes their “paved” street surface to shear and essentially revert to gravel “chunks”, especially if sharp maneuvers are required to navigate into/out of your site. The warmer the weather, the more prevalent the problem becomes. It becomes a maintenance/overhead problem for the campground. The guys with double and triple axle 5th wheels are the ones that can really wrinkle some “pavement” though.