IDumpMack Posted yesterday at 05:05 PM Share Posted yesterday at 05:05 PM I hit the air suspension switch and nothing goes off. Air suspension works as it should just cant dump it. Where should I look at first and how do I diagnose? Quote Link to comment https://www.bigmacktrucks.com/topic/76673-1994-mach-ch613-air-suspension-won%E2%80%99t-deflate/ Share on other sites More sharing options...
Joey Mack Posted 17 hours ago Share Posted 17 hours ago Is the switch connected to a dump valve on the frame or the air tank? 1 Quote Link to comment https://www.bigmacktrucks.com/topic/76673-1994-mach-ch613-air-suspension-won%E2%80%99t-deflate/#findComment-596119 Share on other sites More sharing options...
IDumpMack Posted 13 hours ago Author Share Posted 13 hours ago 3 hours ago, Joey Mack said: Is the switch connected to a dump valve on the frame or the air tank? I will take a good look tomorrow. If it’s connected directly to the air tanks does it need a pressure regulator or anything like that? Quote Link to comment https://www.bigmacktrucks.com/topic/76673-1994-mach-ch613-air-suspension-won%E2%80%99t-deflate/#findComment-596128 Share on other sites More sharing options...
Joey Mack Posted 8 hours ago Share Posted 8 hours ago At the tank would need a pressure protection valve, something like 80 PSI. Quote Link to comment https://www.bigmacktrucks.com/topic/76673-1994-mach-ch613-air-suspension-won%E2%80%99t-deflate/#findComment-596131 Share on other sites More sharing options...
Geoff Weeks Posted 5 hours ago Share Posted 5 hours ago How does the CH do dump? In general, there are 3 ways to do it. 1) uses a small air line (pilot air from the dash switch, air controlled) that operates on a level valve with "pneumatic dump feature". 2) switch is electric and operated a solenoid valve between the level valve and bags. 3) is like the 2nd, but operates and air solenoid that supplies pilot air to an air relay valve between the level valve and bags. If you know which system the truck uses, then you can know the weak points and where they can fail. 2nd and 3rd type have a solenoid and wiring down in the salt and muck spray, the electrical portion is the weak link, but the 1st & 3rd can also have a relay valve that is stuck. The "relay" valve is the same one often used on trailers to dump the suspension when the brakes on the trailer are set. I like the 1st design as it is all air operated and less prone to failure from wiring/electrical issues back on the frame. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/76673-1994-mach-ch613-air-suspension-won%E2%80%99t-deflate/#findComment-596134 Share on other sites More sharing options...
Joey Mack Posted 1 hour ago Share Posted 1 hour ago I expect his to be air over air dump system, with a QR-1 valve after the protection valve, and piloted by an air switch. Quote Link to comment https://www.bigmacktrucks.com/topic/76673-1994-mach-ch613-air-suspension-won%E2%80%99t-deflate/#findComment-596158 Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.