Jimmy Davis

Let ne start by saying, I'm not an air brake expert by any means! Truck is 00 CH613 tri- axle tractor with a 460 & 18 speed. Not sure if the drop axle is factory or not. Problem is the tanks dont equalize at all & secondary will just keep dropping & not kick the comp on. Primary has to drop to kick it on. Also sec wont kick comp off @ 120. This is the one air prob we've not been able to fix. So far replaced foot valve, T&T park brake valve & gov. Thanks in advance!