| Author | Message | ||
| Peter River (Whitebus)
Registered Member Username: Whitebus Post Number: 29 Registered: 4-2009 Posted From: 208.54.14.16  Rating: N/A |
here's a tough one. My bus has air ride suspension. that doughnut shaped bag that's supposed to smooth out the ride. 1. the bags never deflate. I don't see any button or switch to deflate the suspension. is it okay to have that thing fully inflated 100% of the time? is this a result of a blocked air line or something? 2. this is the tough part. when I or anyone else walk around inside the bus, the bus sways from left to right. considering how heavy the whole bus is, should I be feeling a 100lb person walking around when I lie down on the bed? | ||
| Craig Campbell (Craig_4104012)
Registered Member Username: Craig_4104012 Post Number: 12 Registered: 2-2009 Posted From: 72.60.152.143 Rating: N/A |
Wiser people will chime in here shortly but i will add that having read nearly every post through the archives and this year there seems to be a common practice of comparing how long ones coach will stay up. The longer the better. as for the sway, sounds like there is a common line running between the right and left side. by that i mean there is not a leveling valve on each corner that isolates that corners air bag system. so the air is free to move from side to tide | ||
| David Lower (Dave_l)
Registered Member Username: Dave_l Post Number: 140 Registered: 11-2007 Posted From: 67.58.201.132  Rating: |
It will not hurt it to be up. But I must say a word of warning!! NEVER EVER GO UNDER A AIR RIDE BUS WITH OUT BLOCKING THE SUSPENSION OR ON FLOOR STANDS RATED FOR THE BUS WEIGHT!! It can kill or seriously hurt you if the bags sudenly loose air and the bus comes down on you! Dave L | ||
| Bill Gerrie (Bill_gerrie)
Registered Member Username: Bill_gerrie Post Number: 254 Registered: 3-2006 Posted From: 216.198.139.38 Rating: N/A |
Peter There are 3 leveling valves on a bus. One on the front and one on each side at the rear. The front valve controls the front up and down while the rear ones control the rear up and down and also as they are independent of each other they control the side to side level of the entire bus. Unless your bus has a kneeling postion there is no switch to lower the system. If your bus stays up a long time it has a good air bag system. Bill | ||
| Peter River (Whitebus)
Registered Member Username: Whitebus Post Number: 30 Registered: 4-2009 Posted From: 208.54.14.16 Rating: N/A |
my bus don't have a kneeling function. so that means that the valve that control the side to side level is defective? the chassis is made by Spartan. if I take it to a spartan authorized repair facility they can swap out the parts? to be clear, your bus doesn't do this right? (Message edited by WhiteBus on April 30, 2009) (Message edited by WhiteBus on April 30, 2009) | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 663 Registered: 7-2006 Posted From: 75.211.248.36 Rating: N/A |
NO...not necessarily...Bill has it dead on....you might check with the MFGR's specs on this, however. Kneeling could be the "key". Bus air systems are designed to do exactly what you are saying....albeit, "sway" could be an entirely different thing than I am "used to". As I recall, yours is a transit...could be much different than my Highway Coach... FWIW  RCB | ||
| Bill Gerrie (Bill_gerrie)
Registered Member Username: Bill_gerrie Post Number: 256 Registered: 3-2006 Posted From: 216.198.139.38 Rating: N/A |
Peter There is no common line for side to side except at the front. If you walk down the bus you will feel it sway side to side. If it sways too much you could have the height set too high. Look in the book and see what the measurements are. On a GM is is approx 3 1/2" between the rubber on the frame over the axle and the axle itself. Bill | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 879 Registered: 11-2005 Posted From: 208.54.200.17  Rating: N/A |
Same movement happens in my 4104. I think this the natural thing for anything suspended on air. | ||
| Clint Hunter (Truthhunter)
Registered Member Username: Truthhunter Post Number: 158 Registered: 1-2009 Posted From: 24.129.235.190  Rating: N/A |
"if the coach is a rockin , don't come a knockin" was a expression plagiarized from the early days of "customized vans". While not really relevant it does seems appropriate somehow. Your condition seems normal , but the mandatory service & repair manual will best help you understand what is normal when conducting your routine maintenance inspection & service. I noticed when the 10 bags on my MC 8 start to leak down, the bus does rock with less disturbance, matters not if it is a gust of wind or the 3 dogs doing there territory thing, never had the first condition suggested above happen aboard to conduct measurable observations (don't know what the dogs do when I am away), but I keep hoping & trying for some first hand experience on this phenomenon. I'm guessing it would be like wild copulation in a waterbed (if only I could remember that far back). Must be spring or something!!! The remedy in some factory motorhome with air bag springs is the installation of "hydraulic jacks" to stabilize the RV when parked , deployed after the fancy air bag valve system levels the coach. | ||
| Sean Welsh (Sean)
Registered Member Username: Sean Post Number: 837 Registered: 1-2003 Posted From: 72.171.0.140  Rating: N/A |
1. My bus weighs 48,000 lbs, and I can tell when the ~20 lb dog moves around the bus if I am lying in the bed. Yes, this is normal, otherwise your suspension is not working correctly. The only way to eliminate this if it bothers you (and some folks simply can't sleep this way if the spouse is moving around the bus) is to use hydraulic jacks, and unweight the suspension somewhat when parked. 2. I don't know how the Spartan is set up, but I will caution that the unqualified statement that Bill made regarding there being only one valve in the front and two in the rear is not universally correct. My bus has two valves in the front and one in the rear. Same principle, just different layout. You will need to consult with Spartan to find out how your coach is plumbed, or have a look for yourself. Most air-ride coaches do use a three-point ride height system, because a four (or more) point system can impart twisting loads to the chassis. This is something to consider if you meddle with the factory ride-height system to implement a campground leveling system. -Sean http://OurOdyssey.BlogSpot.com | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 665 Registered: 7-2006 Posted From: 75.208.96.90 Rating: N/A |
Mine is set up similar to Sean's, apparently. Reason for that configuration, my book says, is to compensate as folks enter...or leave the coach. We have very little notice of any adjustment..until the air is released and the bags "go down". Then it is minimal. I have been working on this a bit this Spring...tightening connections, checking for leaks, etc,etc. Found a number at the air bag "t's". Things are much improved, now holding 120# for several days...on one side. the other goes down to about 90. I have wondered if that is "part" of the compensation factor. Generally we "dump" the air,even for overnight. Just would rather not have to replace 45 year old tanks.  You might want to check out your valves, as one said above. I had to change one about 8 years ago..fairly easy and not too expensive. Same for the compensation valves. BLOCK THE BUS! FWIW RCB | ||
| john degemis (Degemis)
Registered Member Username: Degemis Post Number: 60 Registered: 3-2008 Posted From: 71.92.155.232  Rating: N/A |
I have been thinking of using 2 leveler jacks that would not be used to level but to stabilize the coach when parked. What I am thinking is placing small units in the rear that would start on the frame and when extended rest on the axel.with a switch wired to the ignition so when the coach is running they would always be in the up position. | ||
| Edward J. Sommers (Sommersed)
Registered Member Username: Sommersed Post Number: 42 Registered: 10-2004 Posted From: 148.78.155.174 Rating: N/A |
I prefer an aired up coach when parked for any time at all because I'm too fat, old and ugly to comfortably access the holds if the rig is not aired up. If heavy winds are coming that can "rock the boat", I place some screw up car jacks under the frame jack points. These work very well and the newer type that come with SUV's are easy to place and raise/lower because of the "shepard's hook" on the twist arm and the hooks hole on the jack. (The old flat type is not user friendly). Once placed I leave them in place till I move. There is no real heavy weight on these jacks as the air system bears the weight, the jacks just handle the rocking!. Ed | ||
| marvin pack (Gomer)
Registered Member Username: Gomer Post Number: 445 Registered: 3-2007 Posted From: 71.55.197.237  Rating: N/A |
Pete over in Daytona Beach, a poster here, has leveling systems on the classified,so look it up and check it out.It may be what you want??? gomer | ||
| Marc_bourget (Marc_bourget)
Registered Member Username: Marc_bourget Post Number: 15 Registered: 10-2006 Posted From: 64.142.42.176 Rating: N/A |
Mr. Sommer's comments triggered the recollection (IIRC) that air is "expended" by the leveling valves reponding to the gusts. This drops pressure almost like a leak. | ||
| Jack Conrad (Jackconrad)
Registered Member Username: Jackconrad Post Number: 1037 Registered: 12-2000 Posted From: 71.3.157.139  Rating: N/A |
Once the air leaks down in the rest of the bus air system, when the leveling valve opens to add air, such as when several people enter the coach, since there is no pressure on the other side of the leveling valve, air wwill leave the air bags. Jack | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 1432 Registered: 10-2003 Posted From: 71.58.110.9  Rating: N/A |
Gus, if you add a rear 4905 stabilizer bar, your 4104 won't rock side to side much if any. | ||
| macgyver (91flyer)
Registered Member Username: 91flyer Post Number: 372 Registered: 11-2004 Posted From: 74.193.225.134  Rating: N/A |
My 4905 doesn't have any noticeable suspension leaks... It stays aired up. Seems like forever... Even when the main tanks are completely dry. Whoever maintained the suspension system on my coach in the past seems to have done a good job of it... The thing was even fully aired up when I went to pick her up. Most of the bags appear new with no cracks from age... Though I'm not sure my levelling valves are working at all... That's something I'll have to look into when I start the conversion process... Which is going to be a while. Cheers! -Mac | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 667 Registered: 7-2006 Posted From: 75.208.96.90 Rating: N/A |
.....you are in the absolute minority, I am quite sure...and very, very fortunate...U need to thank GOD for that!! My guess is that "new" bags all around..(10) is almost unheard of on a coach that is "antique". AND..if no leaky connections...tanks, fittings, valves......well, gee whiz....I am overwhelmed. Good for you!.... But... if all that is so....why...why, aren't you confident about the "leveling valves" working? something seems..uh... amiss...OR? FWIW RCB | ||
| macgyver (91flyer)
Registered Member Username: 91flyer Post Number: 374 Registered: 11-2004 Posted From: 74.193.225.134 Rating: N/A |
I just don't know if they're working or not... I haven't done much to test them... Everything *seems* to work fine, but... As you said, it's antique... I assume nothing and take nothing for granted! I learned that the hard way. ;) The air system itself has a few leaks, but seemingly not on the suspension side of things... It stays aired up for what seems like forever... Even when the rest of the air system goes completely dry... Trust me, I'm not ungrateful, nor unthankful. I just exercise cautious optimism sometimes. ;) -Mac | ||
| Peter River (Whitebus)
Registered Member Username: Whitebus Post Number: 33 Registered: 4-2009 Posted From: 208.54.14.37 Rating: N/A |
macgyver, that's like my bus exactly! My air system has an undiscovered leak where it would completely deplete air tanks in a week (consequently, it would open the front door, which is operated by air - not a good thing) but the air suspension is up 100% all the time. Now I always thought the air system is connected to the air bags in some way, and whatever that is, is clogged up. by the way, when I first got the bus, I took apart the huge bendix air dryer. the thing is full of dessicants and I can see the small plastic pellets all over the place. I think it might have introduced it to the small air connectors and may have jammed it up. by the way, it's nice to hear that others are having the same sway when someone walks around. Bravo to the site owner for creating such a useful site, and all the helpful folks responding to a newbis bus driver | ||
| macgyver (91flyer)
Registered Member Username: 91flyer Post Number: 375 Registered: 11-2004 Posted From: 74.193.225.134 Rating: N/A |
Pete, Sway is normal in an air system... Or any system, really... It's just a function of the suspension. I do notice that the sway I have in my 4905 is considerably less than the spring systems in my previous Bluebirds though... Those BB's just... well... BOUNCE. Air systems seem to dampen things much nicer and just have an overall nicer feel to them... Maintenance costs are higher, but with good reason! My main tank drains off in just a couple of hours... I have a couple of pretty good leaks that need fixing... but yeah, my suspension stays aired up forever... I have yet to see it deflate, honestly. It hasn't been off long enough! XD -Mac | ||
| Clint Hunter (Truthhunter)
Registered Member Username: Truthhunter Post Number: 162 Registered: 1-2009 Posted From: 24.129.235.190 Rating: N/A |
I installed the new style air bags on the rear axle (bought from Mci), they hold air for months on end. Wasn't overly impressed with how they specified the mounting modifications (but it is there modification specs & their liability), and recommend a anti-galvanic barrier such as electric insulation paint between the base and the boggie for long life. Adds extra height potential if I ever install a park&level system & each bag has a built in bumper. | ||
| Bill Gerrie (Bill_gerrie)
Registered Member Username: Bill_gerrie Post Number: 257 Registered: 3-2006 Posted From: 216.198.139.38 Rating: |
Sean The one front valve and two rear valves was just to give Peter a guide. This is the most common way it as done but if yours and his are different I am sure he had an idea of what to look for. Just tried to explain the simplest way to him. Bill | ||
| Buswarrior (Buswarrior)
Registered Member Username: Buswarrior Post Number: 1571 Registered: 12-2000 Posted From: 76.68.133.185  Rating: N/A |
The air in the suspension bellows is locked in there by the leveling valves. There is no reliance on the tank pressure to keep a leak free suspension bellow inflated. Beware the suspension system that leaks down more slowly than the rest of the tanks, as it stays up, and then lowers itself noticeably all at once. You may not know what you have, if it all leaks down together. If some other part of the air system develops a leak/heavier leak, your air suspension may suddenly exposes itself in ways it did not before. SAFETY NOTE: As Jack described, whether you have a one way check valve in your leveling valve assembly/plumbing or not is a HUGE safety issue for crawling under the coach. Without the check valve feature, the bellow will start to deflate backwards into the now empty/lower pressure air tank as soon as the height control valve calls for a top up of air. The descent to the axle bump stops will be a steady rate crush of whatever is in the clearance, not something hollywood, explosive and bounce inducing. Not very glorious, as you most often get to die from lack of air, as you can't breath once your chest is squeezed. There is no way for you to know the height control is about to lean on the valve, and double the trouble if you start monkeying with it without knowing, or happen to jam it while working on other items. A set of wooden blocks that may be easily inserted into the bump stops by reaching around the tire before you go under the coach, handily solves this safety issue. happy coaching! buswarrior | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 674 Registered: 7-2006 Posted From: 70.212.134.131 Rating: N/A |
Thanx, BW...I had wondered about the bump stop thing...glad you confirmed it; albeit, I don't "go under" without wood ramps. Just my way. RCB | ||
| Buswarrior (Buswarrior)
Registered Member Username: Buswarrior Post Number: 1575 Registered: 12-2000 Posted From: 76.71.102.86 Rating: N/A |
Ramps work too!! As long as whatever methods that are used leaves enough room for your body between the ground and the lowest potential for the coach body to settle to, you are good for another go 'round! happy coaching! buswarrior | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 679 Registered: 7-2006 Posted From: 75.210.217.158 Rating: N/A |
Yep....but insurance...??? yep! Hey, a few inches makes the difference...sometimes... Thanx RCB |
