Hello Gentlemen, new to the site but I have to say it looks like I will feel right at home here. Been driving trucks for 30 years and that is long enough to know that Mack is the absolute best truck out there as far as durability, dependability, and value. Especially for on/off road applications which is what I do for a living, hauling dirt, rock, asphalt, etc. Just bought a 99 Mack RD690S tri-axle dump with a Mack E350 engine and Mack 7 speed transmission. The truck was fairly neglected by the previous owner and is fairly rough, but being a Mack is sufficiently sound and solid overall. My problem is the air compressor overbuilds pressure to the point the gauge pegs out over 150psi and yet I don't hear any release valve spit out the excess air. With that much pressure wouldn't it blow out lines left and right, or is it possible the gauge is just defective? And on this model would the governor be located on the firewall or elsewhere? I'm sure I can trace it but just stumbled onto this site and thought I'd run it by you fellas first.