2001 international air brake gauge, need help taking cdl test.

Hello all, I am in a panic. I am taking my cdl test (Class B, not A's) next wednesday.

I am using my International 4700 to take my test. I was practicing my bleed down test and noticed that my gauge and buzzer are out of sink. The gauge with no pressure in the tank still shows 30 psi or so. So my low pressure buzzer does not go off or come on until the gauge shows 90 psi.

I pulled the cover off of the instrument panel and manually pushed the dual gauge arm indicators down to zero but they spring back to 30.

I have been looking for a replacement gauge but can not find any, it looks like the gauge may not be replacement part. May have to replace the whole instrument cluster.

I hope this is not the case cause of the odometer and hour meter.

Can anyone shed some light on this gauge issue?

I will call my dealer in the morning to see if they can get a gauge to me in a hurry.