Original post by: Eric Price ,
air builds high pressure, purges every 15 seconds
Before - Air system builds to 125 psi in primary tank and 120 in secondary tank. Air Dryer purges approximately every 30 to 40 minutes. After - Air system builds to 125 psi in primary tank and 120 in secondary tank. Air dryer purges approximately every 15 seconds. Replaced air governor, air dryer heater and signal hose from the governor to the air dryer ( 1/4 inch hose on air dryer ). The system, then, would build to nearly 150 psi in primary tank and builds to 140 in secondary tank. The air dryer purges every 15 seconds. Removed the air compressor head, cleaned the buildup off the head, also removed, cleaned and replaced the two unloader valves on the top of the air compressor head. No change. 2001 Freightliner Columbia, 12.7 Detroit 470 HP. I think the filter in the air dryer is plugged, that would cause the air to purge more often, but that does not explain the high pressure. I've put the old air governor back on and the pressure still builds high. If I bypass the air dryer completely, do I need to put a 1/4 inch T fitting in the line from the primary air tank to the air governor and splice the signal wire into that, or just remove the fitting from the air governor to the air dryer and cap it off?
air dryer, bypass