bus not level when air up

[Tony LEE]

"When the air bags are working normally, jacking the bus to remove wheels is easy.  Air it up, just set the jack under the jack point, extend so that it is against the jack point, and bleed the air out of the bus.  It'll give you 5" of jacking without any effort.  Don't jack on the axles unless the air is bled out and the bus body is jacked up.
JR"

I don't understand this.  Those jacking points are attached to the suspension below the airbags, so how can airing up and then putting the jacks under the jacking point  assist with raising the axle?

[NJT5047]

"When the air bags are working normally, jacking the bus to remove wheels is easy.  Air it up, just set the jack under the jack point, extend so that it is against the jack point, and bleed the air out of the bus.  It'll give you 5" of jacking without any effort.  Don't jack on the axles unless the air is bled out and the bus body is jacked up.
JR"

I don't understand this.  Those jacking points are attached to the suspension below the airbags, so how can airing up and then putting the jacks under the jacking point  assist with raising the axle?

What I'm describing is airing up the bus to its normal ride height.  Then place a jack under each jack point and snug up the jacks.  No effort so far.
Now bleed the air from the suspension and you just essentially took the weight off the drive wheels and the bus is jacked up 5" higher than at rest with no air....even with the weight of the coach off the drive axle, the wheels are still on the ground, but all you need to remove the wheels is a small bottle jack under the suspension....only the weight of the axle (not the coach) is on the drive wheels. 
Jacking the axle up to remove the wheels only requires an inch or so of easy jacking. 
What this amounts to is saving the labor to jack the coach off the axle....I've done it from an un-aired
position, and used the aired up method.  Airing it up first is much easier.   

Bowmaga, the cost of a conversion kit, I believe, which would include 4  blockoffs and four new style airbags is in the $500 range. 
Mohawk offers these kits.  Mine cost $120 bucks times 4 to replace the bags on the drive axle.  I've got an '87, which has different suspension from yours...no airbeams.  The later bags are easier to replace too. 
I'd recommend locating the source of the leak.  Tony Lee made a good suggestion...but whatever is leaking should be ID'd before throwing bucks at it. 
If you are jacking on a residential driveway, get a piece of 1/2" steel plate about a foot square to jack on.  The jack may go thru the concrete...?   I wouldn't get under the bus or between any components while the bus is  jacked up on a drive way and resting on jacks.   Use this idea at your own risk, but I use a good condition 2' long piece of cross-tie slid beneath the post located between the drive and tag wheels.   They'll safety the rear of the coach.  Jack stands are not useful for low height jacking.  And there's no place on the body proper to block for safety. 
You won't have to get under the bus to get the airbags or leveling valves off.  They can be accessed once the drive wheels are removed. 
Airbeam airbags are ball-busters to change.  Still, it isn't technical...just a lot of bolts and a lot of knuckle work.  Get a case of PB Blaster penetrating lubricant...you'll probably need it.  And anti-depressants.  They'll be a handy chaser for your adult beverages.
This is all totally doable.  Just a good bit of work. 
Try to understand what's leaking before you start removing components.
You could remove the drive axle wheels on the bad side, disconnect the air supply line at the air beams (the air beams have common fittings, the levelers have odd fittings), block off the leveling valve air line end.  Install a fitting so that you can attach shop air to the airbeam. Reinstall the inner dual, snug it up, and add upwards to 60 lbs of air to the airbeams.  If the bus levels and doesn't leak down...the airbeams/bags are working.   Don't add more than 60 lbs of air to the air beams.  Watch the pressure or you may create additional leaks.
If the beams check out, the next place to look at is the leveling valve.  There's a check valve and tiny filter on the leveling valve...and the fittings are proprietary so take care not to damage the fittings and lines.   Checking a leveling valve really consists of replacement and and setting the adjustment.  A pit would be great for this. 
Use a shop air compressor so that the engine doesn't have to run while evaluating for leaks...a regulator in the supply air line set at 100 lbs will protect the bus from too much air pressure. 
Do you have a curb, or low place where you could back the bus so that the rear is hanging over the edge?  Keep the tags on the curb.  This would allow you to safely get beneath the bus and check the leveling valve.  If you have access to a pit, the leveling valve could be checked by removing the link from the axle and simply moving the arm.  It'll inflate and deflate the bags as it's articulated.  As Tony said, the link may be damaged, or the valve is no longer correctly calibrated...or it may be as simple as the bolts on the arm have loosened or one bolt has fallen off.   
Check https://www.mohawkmfg.com/  or US Coach for parts. 
I apologize for being so wordy here...to make this easier...look at Craig's (Gumpydog) excellent website.  He has a pictorial describing airbag replacement on an MCI airbeam MC9.  Craig's site will show exactly what you are going to get into.   I should'a said this first?   
Good luck, JR

[bowmaga]

well, bus day 1 done....and I'd say super Betty won today.  She's up on blocks...the interior is gutted 98%, and we did get the muffler replaced today.  That doesn't seem much, but its a start.  We did start greasing...and greasing everything, but its hard to tell if the zirts are taking good grease with my air greaser....I need to get my dads old hand pump so i can feel it go in.  As for the tag axle issue.  We WERE going to accomplish that this weekend.  I wanted to take the tire off just so we could work on it easier....yea....thats not gonna happen.  I got 2 of the ten nuts off.  no 3/4" or 1"" impact could get them or a breaker bar with 5' pipe and a 220 lb me cranking on it. She is on big frustrating piece of steel.  I did get brave enough to slide under her and start trying to figure things out....i found the rear leveling valves....but can't do anything with them, they don't move and I can't see how to adjust them.  Also, back in the beginning of this posting, someone told me about a valve inside that had something to do with the tag axle air bag pressure.  Well we can't find the valve....but we did find a 1/4" brass line cut off and covered with a piece of duct tape....that was leaking air.  This would have been located to the right of the original shatter, maybe under the sink.  This 1/4" line t'd into a line that went else where.  The tag axle air bags are getting air...its just not dropping down.  Its stuck and we just need to get it yanked down, but haven't figured out a good way of doing that.  There isn't much above it to pry down on and you can't just pull it down, and even if I could, I feel as if I would be pulling against the drive axle air bags and might  hurt them?  Could that happen?

So after today, the bus still leans to the drivers rear corner, The drivers rear drive axle bags kind of get air but not a lot.  The tag axle bags are getting air but its just stuck up in the air and won't drop down.  The tag axle wheel lug nuts pretty much won't come off.  I need a REALLY big compressor.  My 5hp 135psi isn't gonna make it happen.  I may have to drive it into to town to a local shop and see if they can break them loose....in my spare time. ha.  The curb side front and rear air up real good.  And I think i found what used to be a valve...inside.

NOW WHAT?!?!?

[Dallas]

Greg.... remember... those lugnuts on the drivers side are left hand thread....

[Stan]

Before you remove that tag wheel, order ten new studs and nut and have the necessary tools to pull the hub and change the studs. If you can't remove the nuts with 1100 foot pounds or a 1" impact, they have to be replaced as they are stretched beyond their elastic limit.  It is very important that wheels don't fall off when you are driving.

Have you searched this site for info on leveling valves? They are discussed so often, there must be a ton of information on them. If you don't have a maintenance manual and parts book you are fighting a losing battle. If you do have one, study up on a project before you start.

[bowmaga]

Thanks jr., thats the stuff what I need to know.  Don't ever worry about being to wordy....Id rather you be that than to vague!

I figured out the threading mystery about anhour into the process.  I'll work on it more this week and keep everyont posted.

[bowmaga]

well, I got two more lug nuts off the tag drivers side tire tonight....I give up.  Tommorrow there will be a nice big truck show up with a really big air compressor and a guy who will be able to bust the nuts loose in about 10 minutes.  $25.....I just wish i would have called him saturday!  Tonight, I slid under the bus and emptied the air tanks.  Then shut everything up, re-attached the air to the back of the bus and began to air it up again.  She started to look a little different....she's starting to level up, left to right in the rear.  She's now less than two inches out of level, and I think part of that might be in my driveway.  I think airing it up and down is loosening things up and making things work.  Tomorrow I'm crawling under her, and I'm going to spray about 2 cans of pb oil on anything that looks like it is supposed to move. I think spraying the leveling valves will make her level out completely.  I'm feeling positive...I'm feeling positive. 

Now, can some one tell me, or send me picture of what the air valve inside, back by the bathroom is supposed to look like?  I think it controls pressure going into the tag bags.  Mine isn't there anymore, previous owners cut it off and duct taped over the cut off pipe.  Do I need this valve, or can I cap the line and forget about it, can I move the valve into the engine bay?  Talk to me bussers.

[NJT5047]

Forget the ground.  The bus ain't that smart!   
Keep in mind that the bus doesn't do "level" to the ground.  It levels to the position of the drive axle.  If a drive wheel is in a hole, the bus body is going follow the drive axle into the hole.  Period. 
The dimension between the wheels and the wheel wells tells the story. 

You'll have to buy one of those 'big Kahuna' el cheapo 10 HP air compressors and a 1" impact from Harbor Freight.  Their impacts are air hungry, but as long as you use a 3/4" hose and fittings, they'll rip lugnuts off. 
As Dallas said, some lugs are LH on the LH street side of MCIs...not all though.  There are a good many with RH studs all the way around.   I've got one.  The studs will have an "L" stamped on the end if LH.  Since you removed two, you've got this figured out.
Do you have Budd or hub piloted wheels?  Do the drive axles have  acorn shaped lug nuts with a square drive head?    If you have large automotive looking studs...you have hub piloted wheels...if there are two piece lug nuts and screwed on inner dual studs, you got Budd stud piloted wheels.   
Get a torque stick or torque wrench so you can properly reinstall the wheels.   
Another thing, the lugs may be difficult to remove...that isn't unusual.  If the studs are in good condition, they may be fine.  Removing a nut from a torqued stud will always require more...sometimes a lot more, torque to remove.   May seem as though the lugnut  was overtorqued, when they may have been properly installed. 
No harm in changing them out either.   
That mysterious air line may be the bathroom flush line?  They were air operated.  Cap it off and see what doesn't work...if anything.  Do you have a pix of the offending airline? 
JR

[bowmaga]

The tag tires are off the bus.....one step closer to possible levelness.  I got under the bus tonight after i aired it up and sprayed the levelers down with penetrating oil.  hopefully that will loosen them up. Attached are pictures of what it looks like with the tag tires off.  Haven't figured out a great way of getting in and prying the tag down with a big cheater bar.  There is only one spot between the tag beam and the bus frame to get a bar into and pry down and its pretty close to the pivot point.  The inner liner covers everything up.  I think i may pull the shocks off and replace them while the tires are off.  They look awful rusty and maybe they are what is froze up also, maybe part of the problem??  The 3rd picture is of the airlines that used to go to the bus bathroom.  The one when the pen sticking out of it is the line blowing all the air out.  I plan on just capping this off and forgetting about it.  Anyone see a problem with that?  Hopefully i will get a couple more tubes of grease in her over the next few days and get them working up and down.  My grass is growing fast and my house projects still aren't done so I have to split my time wisely.  My wonderful wife feels that the bathroom in super Betty isn't near as important as putting her masterbath back together!  Picking up all eight of my water tanks Thursday!

[Ednj]

In that last picture right there.
those lines went to the door closer and tank rinse for the restroom.
cap them off in the engine bay.

[bowmaga]

good, that's what i wanted to hear about those air lines.  The next thing i need is the air switch to the belt tightener above the engine in the back.  Its the only other thing i can find so far.....so far, that is leaking air.  I hope once these tow items are fixed...she magically she air up level as the first day she was driven!  Then on to my tag axles.....if they would just bust loose.  Next big work day is this sunday...my house if anyone is bored and looking for a bus ride to somewhere.

[NJT5047]

Have you considered overpressurizing the tag axle air bags?  Those things create a quantum bit more downward pressure than you'll ever make with a prybar.
If you choose to use this method of calculated destruction, you'll need some ground rules.
The first process would be to attach an air line and regulator to the tag axle air bag, one side at a time.   The regulator and operator should be behind the bus, away from the subject tag bag.
Once you have a regulated air supply attached to one tag-bag, clear all pets (including children) and helpers away from areas lateral to the wheel well. 
If you have good airbags, you'll be able to exert several thousand lbs of downward pressure on the tag axle arms.   
The tags generally operate at 35 lbs of pressure.  You could double that with good bags to maximize the applied force.   In any event, the regulator will allow you to control  the air pressure.  At least you're not going to blow out an airbeam or any such item.
This process could catastrophically damage the tag bag.  DO NOT OVERPRESSURIZE THE COACH AIR SYSTEM....only one tag bag at a time.  I say that loudly for a reason.   One tag air bag at a time should be worked with.   
If the tags are forced down, you'll have to jack them back up and repeat this process several times and hope that the tag axle frees up.  It may.   If the bags cannot force the unloaded tags down....bummer.  Major bummer.      Do you own a 'fire-wrench'?   
If it doesn't move with 70 lbs of air in the tag bag, you could try some heat...or well placed explosives.   If you use heat, make sure that you deflate the tag bag before you start.   Using heat will damage the tag axle tube seals.  So that begats another major problem...ad infinitum.
Keep in mind that the tag bag could rupture and require replacement.   Anyone near the bag could be subject to death and dismemberment...and be hurt really bad.    Don't let Bubba sit beside the tags and watch the progress while you add air pressure.   
A good safety may be to loosely remount the tag wheel with two opposed lugnuts.  That way the bags cannot damage the tag axle stop if it suddenly works loose.  The tire would also block matter from firing out of the wheel well...into your neighbors front window..    
If you try this (at your own risk, of course), make sure that the block beneath the tag (in your picture) is removed...reinstalling the tag wheel will solve that problem. 

Incogneeter     

 

[NJT5047]

More bad news.  While you're under there, you may wish to replace the upper RH radius rod bushing.   Looks like it's shifted a little. 
They should be, and stay, centered.  If a rod moves forward of the centerline, the busing is worn out.  Just the busing requires replacement....generally.  If it's been driven for long periods with bad bushings, the radius rods will "egg" out and then gotta be repaired or replaced. 
Soak those shock mount bolts with PB blaster.  It doesn't hurt to heat the shock bolt a little.  Let it cool.  Heat it up.  Do this thru several cycles and it may zap right out with an impact wrench and a 6 point impact socket.    If using the ole fire wrench, keep an extinguisher handy...garden hose works fine to that sort of issue.  The rubber bushings in the shocks will burn if hot enough. 
If you manage to get the shock bushing burning, lots of water will put it out.  But you gotta stay with it.  Rubber and urethane parts are sorta hard to extinguish.  Got to get them cooled down.  Then the problem is solved.
JR
Be nice to the shock mount bolts.   You could find that the shock mount is gone....more or less. 
Interesting problem. 

[RJ]

Keep in mind that the tag bag could rupture and require replacement.   Anyone near the bag could be subject to death and dismemberment...and be hurt really bad.    Don't let Bubba sit beside the tags and watch the progress while you add air pressure.   

A good idea here would be to set up a large mirror so you can watch what's happening while you're standing behind the coach.

Dunno why no one's mentioned it before, but if you can reach the leveling valve linkage with a broomstick or similar while standing next to the bus, you should be able to move the valve's arm up/down to see if it actually adds/releases air.  Simple troubleshooting tip. . . if the linkage is accessible.

FWIW & HTH. . .

[bowmaga]

You say i should be able to move the linkage, but i think thats impossible.  I can reach it, no problem,  but the valve arm is attached to a 3/8"  x 1" bar that is bolted to the axel.  unless that bar moves with the axel that valve isn't moving....or am I not understanding how this whole leveling valve actually works with the bus. 

As for the tag.  I think i'm just going to remove the shocks and replace them while I have the tires off.  I'll get those axle's to move up and down one way or another.  I don;t think I have the smarts or the know how at this point to unhook and hook up pressurized air to each tag bag.  I will try the hard way first...pry bar, blocking, grease, jacks, some cuss words, a little praying and some beer.....well a lot of beer.