Air Ride Suspensions

What an air helper spring does

An air spring kit adds an inflatable bladder inside or beside the coil spring, or between the axle and frame on a leaf spring vehicle. Raising or lowering the pressure changes the support the bag provides, so you can level a vehicle that squats under a trailer tongue or heavy payload. It does not replace the main springs, and it does not raise the vehicle's unloaded ride height much. It adds load support on demand.

Kit types and parts

• **Manual-fill kits.** Air bags with a valve at the bumper or hitch area, inflated with a compressor or a hand pump. Simple and economical.
• **On-board compressor systems.** An electric compressor and dash or wireless controller allow changes of pressure on the go. See the Leveling Compressor Kits category for those parts.
• **Replacement air springs.** Standalone bags for existing systems.
• **Adapters, spacers and retaining frames.** Hardware for vehicles with lift blocks, aftermarket lifts or factory air bags.
• **Fittings and valves.** Union tees, height-control valves and similar items.

Choosing a kit

• **Load capacity.** Listings note the working load, such as 2,100 lb for one Firestone coil-spring kit. Use it with your vehicle's rated payload and towing limits, since an air spring does not increase them.
• **Position.** Most kits are rear mounted, and some are for the front.
• **Suspension type.** Coil spring and leaf spring vehicles use different designs.
• **2WD or 4WD.** Some kits fit both, but check, as clearance around the driveline can differ.
• **Lifted vehicles.** If a lift block or aftermarket lift is in place, a bag adapter or spacer may be needed to restore the proper bag height.

Installation and use

Confirm fitment for your exact year, make and model and the suspension setup. Installation is typically bolt-on with limited drilling, but you must route the air lines away from exhaust and sharp edges and seal the fittings. Test for leaks with soapy water.

Observe the pressure range stated by the manufacturer, and never exceed it, since the bag can fail. Keep a small amount of pressure in the bags at all times, even when unloaded, to prevent folds that wear them out. Suspension work is safety related, so consider professional installation if you are not experienced. Air springs also do not substitute for correct trailer tongue weight and brakes.

Before choosing, check your rear suspension: coil springs or leaf springs, the available space between the frame and axle, and any aftermarket lift that changes that gap. Measure the compressed and extended heights if the kit lists a bag range. Check clearance around the exhaust, brake lines and shocks.

Often paired with air springs are a compressor system, spare fittings, a gauge, and quality air line. Common mistakes include running the bags at zero pressure, which lets them fold, inflating beyond the stated limit, and routing air lines near hot exhaust parts. Inspect the bags for cracks, rubbing and abrasion, and check the fittings for leaks with soapy water. Look at the brackets and hardware after trail use and tighten them as needed. In cold climates, drain moisture from any air lines or tanks to avoid freezing.