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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Fred Mc on September 14, 2017, 10:53:13 AM

Title: Help!!bus won't air up at campground
Post by: Fred Mc on September 14, 2017, 10:53:13 AM
So ready to leave campground with pd4106 and it won't air up. Air seems to be leaking from govenor( I think it's the govenor-round housing attached to compressor. What can I do?
Thx
Title: Re: Help!!bus won't air up at campground
Post by: gumpy on September 14, 2017, 10:57:32 AM
First, try smacking it with the plastic end of a large screwdriver or a small plastic or rubber mallet or hammer. Sometimes they stick.

Otherwise, replace the governor. They're about $15 at a truck parts supply. If you can't get to one, pull it apart, clean it and grease it and put it back on.  Be careful not to damage the o-rings or gaskets.
Title: Re: Help!!bus won't air up at campground
Post by: bevans6 on September 14, 2017, 11:12:33 AM
The governor is just a shuttle valve with a spring.  High air pressure, valve closes against the springs pressure, sends air to the compressor to tell it to stop delivering air and to the air dryer to tell it to purge.  Low air pressure, spring opens valve,  air compressor starts to deliver air and air dryer closes its valve and stops purging.  When/if you take it apart, preserve the spring setting so you get it back about right.  I haven't taken one apart, but counting turns on the adjuster comes to mind.

Brian
Title: Re: Help!!bus won't air up at campground
Post by: chessie4905 on September 14, 2017, 12:30:35 PM
Or carefully measure threaded stud protrusion before you loosen locknut when taking apart. It's under rubber flap on top unless gov is mounted upside down or sideways. If you decide to disassemble, go to Bendix web site or utube for rebuild info.Those things are cheap enough and common enough to just replace it. Be careful to install threaded plugs supplied into proper ports on rebuilt unit or you'll have new problems.
Title: Re: Help!!bus won't air up at campground
Post by: Utahclaimjumper on September 14, 2017, 02:22:13 PM
 Also available at NAPA stores.>>>Dan
Title: Re: Help!!bus won't air up at campground
Post by: Fred Mc on September 14, 2017, 03:12:57 PM
Thanks all. So after calling 3 mechanics to no avail I called a tow truck which was going to be at least a couple of hours. So I fiddled with it a bit more. Couldn't  take it right off and attempt to take it apart as I would then need new hoses as old ones look like they would be ruined tget it off. So tapped it a few more times with a wrench and it started to work so was able to get it home. Seems to work now but I'm sure will quit again so will get a new one.

Another problem now. Reverse solenoid quit working. Took it off and cleaned it and it works fine in the bench but not on bus. Is there an adjustment in the linkage needed.
Title: Re: Help!!bus won't air up at campground
Post by: Utahclaimjumper on September 14, 2017, 04:41:44 PM
 Are you sure its getting 12 volts "on the bus"??>>>Dan
Title: Re: Help!!bus won't air up at campground
Post by: gumpy on September 14, 2017, 04:44:16 PM
Quote from: Fred Mc on September 14, 2017, 03:12:57 PM
Thanks all. So after calling 3 mechanics to no avail I called a tow truck which was going to be at least a couple of hours. So I fiddled with it a bit more. Couldn't  take it right off and attempt to take it apart as I would then need new hoses as old ones look like they would be ruined tget it off. So tapped it a few more times with a wrench and it started to work so was able to get it home. Seems to work now but I'm sure will quit again so will get a new one.

Another problem now. Reverse solenoid quit working. Took it off and cleaned it and it works fine in the bench but not on bus. Is there an adjustment in the linkage needed.

replace or rebuild the governor. I had one do the same thing. always at the most inconvenient time. I replaced it and then rebuilt the old one and put it back on. Worked great. That was about 15 years ago. Still carrying to new one around as a spare.

Can't help you on the reverse linkage. Maybe needs lubrication.
Title: Re: Help!!bus won't air up at campground
Post by: Scott & Heather on September 14, 2017, 06:28:23 PM
And the bus gremlins start coming out. I feel your pain. I can't help with the reverse issue either but here's a free bump to the top


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Title: Re: Help!!bus won't air up at campground
Post by: chessie4905 on September 14, 2017, 06:31:17 PM
Per the GM manual....be sure transmission control linkage is properly adjusted. Place gearshift lever is in first speed position. Disconnect wire from terminal and remove cover from solenoid. Inspect contact points. If points are burned or pitted, replace points or dress with a fine points file. Operate lever while observing contact points. A lever pushes plunger inward, plungr must contact pin and open points when plunger reaches end of stroke. When current is supplied to solenoid, both coils are energized ad cause magnetic pull on plunger, but when points open, the circuit through pulling coil is broken and only the holding coil remains energized . Damage to coils may occur if the point do not open at end of plunger stroke.
If necessary to make an adjustment, loosen locknut, remove clevi pin. Turn clevi while holding link assembly. Reinstall clevis pin and tighten locknut. Verify points open at end of lever travel. Replace cap and wire. Verify that reverse now works.
I had this problem on my 4104 several years ago. Turned out that linkage wasn't sloppy enough. I removed the slop one day, thinking it was worn. After that, I had trouble getting into reverse when trans was warmed up. Got a new solenoid from Luke; same problem. I the adjusted it by the book and NEVER had that problem again.