No air getting to suspension

[Nineforever]

I'm new to the board but have been installing  and replacing parts on my 81 MCI for the past 2 years
Rebuilt 8v71n by Detroit
Rebuilt transmission by Allison
Brakes wheels drums and tires replaced
Basement rad new
Rear engine rads both sides new
Suspension plates and bags drive axle and front axle
Had the bus up and running fine in the drive way 2 weeks ago started up last week now i cant get air to the suspension ? Bus is building air to 120 and exhausts threw air dryer as it schould any help would be much appreciated.

[Oonrahnjay]

   Do you have an "accessories" tank separate from the brake tanks?  If so, is there a pressure gauge for it?  Do you have a schematic for your brake system?

[Dave5Cs]

stuck open exhaust on your leveling valves possible. Is it very cold where your bus is, could there be ice in the bag lines? Bad check valves? open accessories tank valve? Just some thoughts.

[Nineforever]

I have the front of the bus blocked up of the ground would that be causing mixed signals to leveling valves ?

[Nineforever]

I don't have air schematics for the bus , when you say @$# air tank do you mean the air tank below driver seat front compartment ? I installed sniffer bottle to the system filled with air brake anti freeze still same problem

[Len Silva]

I have the front of the bus blocked up of the ground would that be causing mixed signals to leveling valves ?

That's most likely the problem.  The leveling valves are exhausting air trying to lower the bus.  You should be able to hear the valve dumping air.

[Joe Camper]

That is for sure the problem for the front.

Disconnect the linkage for the ride height valve and manually move the arm to the other direction and the bags will begin to inflate.

Right now the height valve is saying too high to high go down go down LOL

Be very careful

[Oonrahnjay]

Is it very cold where your bus is, could there be ice in the bag lines?

    No, Dave.  It can't be that.  I'm sure that if he was living someplace really cold, that would have been the first thing that he mentioned in his post.  He's probably in Arizona or San Diego watching the palm trees blow in the warm breeze.

[Nineforever]

As you said Len .... bus was blocked up high in the front that's why no air to the front bags i put the front wheels back on and lowered the front down so the front wheels were on the ground then the bags loaded .
Thankyou

[muldoonman]

Nine, sometimes these buses are smarter than we are. I know mine is.

glen