Truck with no air dump valve switch, can one be installed?

I’ve been working a project the last few weeks, that requires lowering truck and trailer.

You can easily disconnect the leveling valve on the tractor and raise or lower.

I installed an air dump switch on the trailer, manual, at the rear. I had to replace the 2 port leveling valve with a 3 port.

I assume you’d have to do the same on the truck and run air lines into the cab to the switch.

I think there’s an air/electric option too.

 

Yep! Several ways to go about it, just need a valve that block the input (from the height control valve) and dumps the bags when air is applied. It could be as simple as a 3-way valve outside the cab, or using a relay valve like the factory setups controlled from the dash.

 

My tiny brain had issues with the way it worked - I needed to have air supplied to the brakes to roll the trailer whilst the bags were dumped.

I finally figured out that the 3 port allowed both these functions, and relied on fully charged air system.

 

If I don’t forget I’ll take a picture of my factory setup and share as well. Very easy to add on external or in the cab….

 

They make leveling valves with the dump pilot integrated, or you can purchase a dump valve that goes on after the leveling valve. The dump pilot port has a valve that is normally held open when there is no air supplied to it. This allows the system to function normally. When you supply air to the pilot, it closes off the air from the leveling valve and it opens the exhaust port, which allows the air bags to empty into the atmosphere.

You have to decide which method you will use to supply air to that pilot port, and how you will control it. You can run a line from the tank(tee off of any line that always has tank pressure) to the pilot and put a simple ball valve that you open and close by hand. If you don't want to get in and out of your cab every time you do it, you can install the valve on your dash, but then you will need to run air lines to and from that valve. You can also run a normally closed electric solenoid valve, then run the wires to a switch on the dash. When you flip the switch and energize the solenoid, it opens the valve and air flows to the pilot, which dumps the air bags. It is a good idea to put a light or buzzer on that switch so it reminds you to inflate your suspension before you drive off.

 

I had a dump valve installed on a century. I *believe* its electric, but confess I didn't pay a lot of attention.

 

There is NO kit but it is easily setup.

You need a Hendrickson VS-228 with integral dump valve

You will also need a dump valve or any air valve.

AND you will need the DOT 1/4" tubing to go from the valve for the air bags (VS-228) and the dump valve - maybe 25 feet should do it.

The way the VS-228 works is you just need to open the dump port and it releases the air out of the bags.

There is instructions on the Hendrickson's site - pretty clear on how to install it

https://www.hendrickson-intl.com/getattachment/3542de72-3d8e-4f02-ab4c-ceec52105bdd/L1115.pdf

 

This is the right answer.