air pressure gauges at different pressures?

[wizner17]

on my m931a1 the primary air pressure is 125psi, while the secondary is reading 135psi. i went through the trouble shooting tm's and only found info on what to do incase of overpressure on the primary. and i couldnt find a second governor for the secondary air side, so im assuming it all shares the same governor.

tonight i will adjust the governor so the secondary will read 130psi, but then the primary will probably read 120psi, which is technically fine. but its just annoying that they're not the same. also tonight ill flip the air lines to the gauges and see if its reading the same just to check themselves. but any other ideas?

 

[bearboley]

Driving trucks for 20 years I have never seen the pressures match on the air gauges. You will get dizzy chasing your tail.

 

[seano11]

Yup looking at my gauges right now in my kw both are different and so if my fuel gauge

 

[wizner17]

alrighty then, i guess its a pretty common occurance. thanks for the replies before i start chasing my tail, cause thats exactly where i was headed

 

[rickf]

Switch the lines to verify and give yourself peace of mind and then remember to switch back. Most gauges have a small amount of adjustment with a little screw on the lower face or back of the gauge. You want to check with a third gauge first though to make sure you are adjusting the right gauge.

 

[wizner17]

i didnt know about the adjustment screw, ill have to look into that. im first planning on getting a calibrated gauge and adjusting the governor to 130, and then i can just adjust the stock gauges. that sounds good, thanks for the tip

 

[rickf]

Not all gauges have it but most quality gauges do.