Primary gauge shows no lbs, with no buzzer. Bad gauge?

Stop......then apply pressure to the pedal....if your guage that shows how many pounds your applying reads 30 or more pounds, and you check it this way a few times its a bad guage....but I will say its probly not to safe to drive with that particular guage out of order.

 

Is the truck running?

 

the primary gauge wouldn't stop the truck from functioning. but it would be a oos violation.

if the truck builds air and can roll. that's all that's needed. a defective gauge is just something that needs to be fixed before a level one happens.

but yeah, is the truck running.?

 

Some trucks have mechanical gauges, some are electrical, some are electronic and some are digital. Some trucks have separate sensors for the low air, some truck dashes are pre programmed to turn on the warning buzzer when the gauge gets down to a certain mark, (electronic and digital). All trucks are also required to have a visual warning light when one system is down. If you aren't getting the audible or visual warning with the one system, buy you do when air is pumped down, chances are it is just a gauge.
What kind of truck, model, year?