4104 Problems a plenty

[travcojim]

Just a short recap,  I have a 4104 that normally starts fine and everything runs great with no problems.  I hadn't started it for a few months and when I started recently I had no airpressure, also when I put it into gear, nothing.  No movement, it ran for about 10 minutes and the airbags never inflated.  Then, I hit the kill switch and got nothing.  Engine did not shut down.  I had to end up starving the bus for air to get it to shut down.  Rather scary..  Is there something that would cause all of this of a sudden. 
  Still learning my way around the bus so any direction would be great..

[LuckyChow]

Travcojim,

No air pressure will cause the air bags to not inflate, and it will cause the engine to not shutdown when you turn the switch off.  The shutdown skinner valve is air operated.  I don't know what your transmission setup is.  If it has been changed out to an automatic with electronic control, no air pressure might have locked it out. 

Most of your mentioned problems have to do with not building air.  Air problems tend to be worse in the winter when it is cold.  It could be a very simple problem with the air dryer dumping air due to a stuck purge valve, or the air governor on the compressor.  Air problems can be fickle.  The next time you start it, it might be fine, especially if the day is warm.  Typically air problems are not hard to fix and usually not expensive. 

[Dave5Cs]

There should be a fuel shut off near your fuel pump or filters. Also at your skinner valve that shuts down the motor when there is air has a rod sticking out of it with a lever. If you clear that lever and gently pull on the rod it will stop it next time. Connect shop air to the rear fitting you should have on the rear wall somewhere. Pump the system up and leave the hose connected as you use a squirt bottle of soap and water.

Shoot all the fittings and look for bubbles. Fix and or tighten the ones that do. Shoot all the air valves as you go. 1st make some ramps you can drive it up on or jack it up at the proper jacking points and fully block the bus on good blocks as well as chalking the tires. Never get under an air bag bus before it is blocked.

Also have someone step on the Brake pedal and listen at each wheel to see if any leaks at the brake can diaphragms.

Dave5Cs

[wg4t50]

Not knowing the history on maintenance, I could also see water (Frozen) in the air system, just a guess, seen dumber things once.

[travcojim]

Thanks for the leads, I will look into this weekend if its not too cold out.  Bus has been maintained well, just not put out on the road much in the past few years.  Will update when I get something figured out.

[robertglines1]

I'm on the tell it like it is day the more info you share= more you get.. general local =busnut nearby==bus but with same problem.  Maybe recognize bus previous history/ Don't need you social telephone etc...  there are lurkers here that would tear your  few $$$ up in a heart beat---real world..Is Jim a name to address you BY?  It's cold most everywhere wisc  or missippi?   Bob

[gus]

As wg said, probably frozen air lines.

You can easily shut the engine down by hand, just push (pull?, can't remember) the shut off valve rod where the air cyl is attached at the cyl head.

You can also manually release the spring loaded emergency shut down at the engine.

What trans do you have? If you have an AT it probably won't work without air.

[travcojim]

I will provide as much info as I can, yes, Jim is my name, and I am in Northwest Arkansas.  So our cold is not that cold, but still in the teens and low 30's for the highs lately.  The bus belonged to someone else who didn't have much of a chance to use it.  He purchased the bus about 7 years ago from Hot Springs Arkansas from the owner who traveled from the area to Alaska where he lived in it for a few years on and off.  If I am not mistaken it is number 161, a 1954 model.  Engine and tranny from what I understand have been gone thru before it was purchased 7 years ago.  It is the 4 speed transmission.  I have been more or less the caretaker of the bus for the past 6 years.  Now the owner is leaving the country and the bus has been handed over to me.  I have driven it in the past but only on a few short runs.  I have all the manuals along with the gm parts catalog from when the bus was new. 
  Hub mileage shows about 59,000 miles.    The conversion is a professional one, no short cuts or cheap materials.  I am not sure if I am keeping the bus or not, I have a 67 Travco also.  But I am planning on keeping it in top running condition so the current problems have me a little puzzled.  Before this problem the bus has never missed a beat.  Always fired up on the first turnover.

[robertglines1]

That give everyone a Idea/place to start.  Lots of Ark guys and close around...general condition of bus. and maybe you just need a walk thru procedure update. Not really familar with your particular set up but first impression is your air pressure isn't building.My first ck  are the AIR tank drain valves closed---this is a common practice of some old trimmers to leave them open. 2nd  do you have any way to hook up a outside air supply to bus system to ch for a massive air leak your compressor couldn't keep up with?..Mouse ate my primary line into once!!!   FWIW  Bob  SW  INDIANA

[travcojim]

I know for sure its not a valve left open, I was the last to start it a while back and it aired up fine then.  Are the air lines rubber?  You said you had a mouse eat thru one.  Where would I check just in case, how are they routed from rear to front? 

[robertglines1]

locate compressor--then to a dryer(90%) buses have---- them to 1st tank.  usually in a enclosed metal pipe or pvc  sometimes of that vintage just strapped to frame.  On top of compressor there should be a larger line coming out that should be air to bus-first tank.  Also largest in is fresh air supply.  most have a hose with filter some older just like a home compressor filter 90% of buses will have a hose running to air cleaner or intake runner for air supply to air compressor supply.  muake sure it is free to breathe first.  then follow the flow  to compressor  pump--ot to line--thru hose --to dryer---to wet tank--The ac compressor has a governor little rectangular looking screw in the side piece that stick when sitting a time that's low dollar  LETS   see how far your air is not getting first  follow the path.  is it getting to the compressor?  out ?  past the dryer? to the wet tank?  old lines like old people crack and break.  mice are just plain aggravating and eat hole in things in odd places .  If you have any compressed air source once you have made sure your compressor has supply or fresh air and is working might save you running engine.  Good luck...

[John316]

My guess is unloaders. We just went through that on our bus. Basically that is what tells the compressor to turn on and off, after it gets a signal from the governor. Actually could be the governor (certainly cheaper to replace).

If it was me, my next step would be to hook up shop air to it, like Bob said. See what happens.

[travcojim]

I am going to start at the rear and go thru everything.  Between the good info that I have gotten and the maintenance manual I hope to have something figured out soon.  I will let you know what I come up with.  Happy Thanksgiving everyone.

[chessie4905]

  First, what are the outside temps there, esp at night? If they are 32 or less, then I'd wait for temps to get up in the upper forties for several hours, then try again.