Air Suspension 101: Part 4

Now that you understand the two basic air suspension components, it is time to look at valves and gauges. This month we will discuss the items needed to control the air in the air suspension system.

A valve is essentially a device that allows the air to flow when open. This works the same as any valve such as a water faucet. When it is open, air flows through it and when it is closed, air stops flowing. The valve is placed after the air tank and before the air bag.

There are two types of air valves: manual pneumatic and electric. A manual pneumatic air valve is commonly referred to a just a manual valve. This type of valve is similar to turning on your faucet to get water. You have a switch or lever that is attached directly to the valve. When you press the switch or lever, valve is open. When you let go of the switch or lever, the valve is closed. Most manual valves are two way valves. This means that one valve will let air in the air bag and also release air out of the air bag. You would need two manual valves for a front and back system; and four manual valves for a FBSS (front, back, side, side) system.

The manual valve is located inside the cab of the vehicle. Air line is run directly to the valve. When the switch is pressed to let air out of the bags, you will hear it within the cab of the vehicle. This is because the valve is located inside the vehicle and the air is release directly from the valve.

Manual air valves are the cheapest of the valves. The better air valves are electric. Electric air valves use electricity to open and close the valves. These work similar to the manual valves except they can be mounted anywhere. This means that when the air is released from the air bags, it does not have to be release inside the cab. Electric valves need to be wired to an electric switch. When the switch is pressed, it energizes the valve which opens it and lets air in. The advantage of this setup is that it allows you to use multiple switches to do things like pancake, all up, all down, side to side, etc. That is why most front, back, side, side systems come with a 10-switch box.

Most electric valves are one way. This means that you would need one valve for airing up the bags and one for releasing the air from the bags. So if you wanted a front and back system, you would need 4 air valves. For a FBSS, you would need 8 valves.

Gauges are used to monitor how much air is in each bag. Gauges can be either analog (meaning they have a needle) or digital. There are two types of analog gauges, single needle and dual needle. A single needle gauge will monitor one pressure from a single gauge. A dual needle gauge has two needles in one gauge. This allows you to monitor two separate air pressures. If you have a front and back system, you would need two single needle gauges or one dual needle gauge. For a FBSS system, you would need 4 single needle gauges or two dual needle gauges.

Most analog gauges are mechanical. This means that you need to run an air line directly to the gauge. The air line is teed between the valve and the air bag. Digital gauges are electric and use a sending unit. The sending unit is places in between the valve and the air bag. A wire is run from the sending unit to the gauge. There are some analog gauges that are electric also, but the most common is the mechanical gauges.

As always, if you have any questions on this, please let us know. We will continue next month to discuss air suspension in greater detail.

Vincent Wright
sales@kmwperformance.com
http://www.kmwperformance.com