adjusting trailing axle and towed cars

[patrick mckenzie]

I'm looking for advice. I'm new here and hope i am doing this right and can find again. I have replaced the trailing axle on my 84' 345 with new controllers one for each side working together to control the rear axle air bags. Even though the controllers let air in and out they do not seem to adequately adjust air when in use letting air out easily but not in as if their is not enough leverage. I have tried both holes on the lever arm. I may be to worried but after driving the trailing axle wheels are splayed out though I can easily them back up to spec. manually.

[thenewkid64]

Welcome to the forum!

If I understand the question:

Airbags will hold air, you can fill manually, they lose air as you travel. Right?

You have replaced the leveling valves on both sides, right?

Does the compressor come on when you start the MH? What air pressure does the dash gauge show?

When you installed the new valves could you have installed the fill and dump tubes in the opposite holes?

Answers to these questions will help us to long distance troubleshoot.

[87MH]

On my 345, it takes a bit of forward movement for the bags to properly inflate.

It seems that the control valves require a bit of "on the road" time (a couple of body roll cycles) to "find their groove". If you make a setting change, drive it around the block and observe where the "bag height distance" stabilizes.

Another point, if you have replaced the tag axel, once you get the bags set to where you think they should be, you really need to record the weight supported by each of the four rear tire support areas (the right and left duals, and the right and left tags). If the rear bags are riding too high, too much weight is being carried on the main axel, and the tags are not carrying their fair share of the load. Conversly, if the bags are set too low, the tags will be carrying more weight than what they are rated for.

The only way to check the proper suspension setting (bag height) is to take the vehicle to a scale and record the weight that each of the four rear axel road contact points (tire groups) is actually supporting.

The following threads contain pertinent information.


http://www.airforums.com/forum...ght=bag+height

http://www.airforums.com/forum...ght=bag+height

http://www.airforums.com/forum...ght=bag+height

http://www.airforums.com/forum...ght=bag+height


More threads can be found by using the "Search" icon at the top of your screen and do a search on "Ride Height", "Rear Suspension", or "Bag Pressure".