GMC Motorhome Air Suspension Parts: A Complete Guide to Upgrading and Maintaining Your Ride

If you own a GMC motorhome, you already know that the ride quality and handling depend heavily on the suspension system. Many classic GMC motorhomes, especially the GMC Motorhome models from the 1970s, came with air suspension as standard. Over time, these components wear out or become outdated. Replacing or upgrading your GMC motorhome air suspension parts can dramatically improve ride comfort, stability, and safety. In this guide, we’ll walk you through the essential air suspension parts, what to consider when buying, and how to keep your system in top shape.

Why Upgrade or Replace Air Suspension Parts?

Air suspension systems use air springs instead of conventional coil springs or leaf springs. They allow you to adjust ride height and stiffness, which is especially useful for motorhomes that carry varying loads. Over time, air springs can develop leaks, compressors can fail, and control systems can become unreliable. Upgrading to modern components can restore or even surpass the original ride quality. Many GMC motorhome owners replace their air suspension parts to eliminate sagging, reduce body roll, and improve towing capability.

Common Signs You Need New Air Suspension Parts

• The motorhome leans to one side when parked.
• The air compressor runs constantly or never shuts off.
• You hear hissing sounds from the suspension.
• The ride feels harsh or bouncy.
• The vehicle sags significantly when loaded.

If you notice any of these, it’s time to inspect your air suspension components.

Types of Air Suspension Systems for GMC Motorhomes

GMC motorhomes originally used a simple air suspension system with air bags, a compressor, and basic height control valves. Today, you have two main options when replacing parts:

Original Equipment (OE) Style Parts

These match the original design and are often direct replacements. They’re usually less expensive and simpler to install. However, they may not offer the same durability or features as modern aftermarket parts.

Aftermarket Upgrades

Aftermarket air suspension parts are designed to improve performance, longevity, and adjustability. For example, many owners replace the original rubber air springs with high-durability double-bellows or rolling-lobe air springs. Some aftermarket systems add electronic controls that let you adjust ride height from inside the cab. While these cost more upfront, they can provide a smoother ride and better load management.

Key GMC Motorhome Air Suspension Parts

Understanding the individual components will help you make informed choices when buying parts.

Air Springs (Air Bags)

Air springs are the rubber bags that support the vehicle’s weight. In GMC motorhomes, they are usually located at each wheel. Over time, rubber can dry rot, crack, or develop pinhole leaks. Aftermarket air springs are made from stronger materials like reinforced polyurethane or heavy-duty rubber with multiple bellows. When replacing, ensure you get the correct size and mounting configuration for your year and model. Measure the distance between mounting points and the diameter of the air fitting.

Air Compressor

The compressor pressurizes the air tanks and air springs. Original GMC motorhomes often used a small electric compressor that may struggle to keep up with leaks or multiple height adjustments. Upgrading to a larger, more efficient compressor (e.g., 12V or 24V) can speed up inflation and improve reliability. Look for oil-less compressors that require less maintenance. Many aftermarket compressors come with built-in dryers to prevent moisture damage.

Valve Blocks and Height Control Valves

Valve blocks distribute air to individual springs. In the original system, mechanical height control valves open and close to maintain a preset ride height. These can stick or fail over time. Aftermarket electronic height sensors and solenoid valve blocks offer precise control. Some systems include a handheld remote or in-dash controller for on-the-fly adjustments. If you tow a car or carry heavy gear, electronic control makes it easy to level the motorhome.

Air Tanks

Air tanks store compressed air. Larger tanks provide reserve capacity, reducing compressor cycles. Some GMC owners add a second tank for faster response. Tanks are usually steel or aluminum; aluminum is lighter and corrosion-resistant but more expensive.

Fittings, Lines, and Wiring

Don’t overlook the small parts. Air lines can crack, and fittings can leak. When replacing components, use nylon or DOT-approved air brake tubing. Brass or stainless steel fittings resist corrosion better than plastic. Proper wiring and relays ensure the compressor gets enough power.

Buying Considerations for GMC Motorhome Air Suspension Parts

When shopping for parts, keep these factors in mind:

• Compatibility: Verify part numbers for your exact GMC motorhome model year. GMC produced several variants (e.g., 23-foot and 26-foot models) with different suspension setups.
• Load Capacity: Choose air springs rated for your vehicle’s gross vehicle weight rating (GVWR) plus any extra load you carry.
• Durability: Look for parts with warranties. Polyurethane air springs last longer than standard rubber but may be stiffer.
• Ease of Installation: Some components are direct bolt-on; others require drilling or fabrication. If you’re not mechanically inclined, factor in professional installation costs.
• Brand Reputation: Stick with established air suspension brands known for quality. Avoid no-name parts from discount sellers that may fail quickly.
• Complete Kits: Many suppliers offer complete air suspension upgrade kits for GMC motorhomes. These include all necessary hardware and instructions, simplifying the buying process.

Installation and Maintenance Tips

Replacing air suspension parts can be a DIY project if you have basic mechanical skills, but safety is critical. Always support the motorhome on jack stands, never just a hydraulic jack. Follow these steps:

1. Depressurize the system and disconnect the battery.
2. Remove old components carefully to avoid damaging nearby brake lines or wiring.
3. Install new air springs by attaching the mounting brackets and air fittings. Use thread sealant on fittings.
4. Run new air lines away from exhaust and sharp edges. Secure with clamps.
5. Wire the compressor and controls according to the kit instructions. Use fused connections.
6. Test the system by inflating to operating pressure and checking for leaks with soapy water.
7. Adjust ride height per manufacturer specs.

Regular maintenance includes:

• Inspecting air bags for cracks or abrasions every few months.
• Draining moisture from air tanks (if equipped with drain valves).
• Checking compressor air filter and cleaning or replacing as needed.
• Listening for unusual compressor cycling or leaks.

Final Recommendation

For most GMC motorhome owners, upgrading to a modern aftermarket air suspension kit is the best investment. It will provide better ride quality, easier leveling, and longer component life. Start by replacing the air springs if they are original or leaking—they are the most common failure point. Then consider upgrading the compressor and adding electronic controls for convenience. If you plan to keep your motorhome for years, spend a little more on durable components. Stick with reputable brands and complete kits to avoid compatibility headaches. With the right parts, your GMC motorhome can ride as smoothly as a modern coach, making every trip more enjoyable.