HD Value HDV9978 Air Spring | Replaces Hendrickson S-28929

HD Value HDV9978 Air Spring – Hendrickson S-28929 Replacement

Restore dependable air suspension performance with the HD Value HDV9978 Single Convoluted Air Spring, a heavy-duty replacement air bag designed for compatible commercial truck and trailer air-ride suspension systems.

Engineered as a replacement for Hendrickson S-28929 and Firestone W01-358-9978 applications, this air spring helps support vehicle loads, maintain proper suspension ride height, and absorb road vibration during demanding commercial transportation operations.

Featuring a 12.60-inch maximum diameter and a listed height range of 7.88 to 19.61 inches, the HDV9978 combines heavy-duty rubber construction with corrosion-resistant components for dependable performance in properly matched air suspension assemblies.

Whether you're replacing a leaking trailer air bag, repairing a Hendrickson air-ride suspension, or performing preventive fleet maintenance, the HD Value HDV9978 offers a cost-conscious aftermarket replacement option.

Part Number: HDV9978 | Replaces Hendrickson S-28929 | Firestone W01-358-9978

HD Value HDV9978 Features & Benefits

• Hendrickson S-28929 Replacement: Designed for compatible Hendrickson trailer suspension applications.
• Firestone W01-358-9978 Cross Reference: Associated with the widely used 9978 air spring family.
• Single-Convoluted Design: Heavy-duty air spring construction for compatible commercial vehicle suspension systems.
• Heavy-Duty Rubber Bellows: Formulated to withstand demanding suspension movement and load fluctuations.
• Ozone and Temperature Resistance: Specialized rubber compound helps resist environmental deterioration.
• Corrosion-Resistant Components: Electroplated components help protect against corrosion in demanding road environments.
• Air Suspension Support: Helps maintain proper ride height when installed in a functioning air suspension system.
• Reduced Vibration: Helps isolate road shock and vibration from the vehicle and cargo.
• Commercial Trailer Applications: Suitable for qualifying dry van, refrigerated, flatbed, and other air-ride trailer suspensions.
• Aftermarket Replacement: Engineered for compatible OEM dimensional and functional requirements.

Replacement for Hendrickson S-28929 Trailer Air Springs

The HD Value HDV9978 is a replacement option for compatible air suspension systems using Hendrickson S-28929 air springs.

Hendrickson air-ride suspension systems are commonly found on commercial trailers where air springs provide load support while helping reduce road vibration and maintain suspension ride height.

Replacing damaged or leaking air springs helps restore the suspension's ability to maintain the proper air pressure and vehicle position.

Important: Hendrickson uses multiple air spring configurations. Verify the original part number, suspension model, mounting arrangement, and air connection locations before ordering.

Firestone W01-358-9978 Cross Reference

The HDV9978 belongs to the same commonly referenced replacement family as the Firestone W01-358-9978 air spring.

This makes HDV9978 a useful aftermarket option when repairing compatible commercial trailer air suspension assemblies originally equipped with the specified Firestone or Hendrickson air spring.

Always confirm component dimensions and mounting configuration before treating cross-referenced products as interchangeable.

Heavy-Duty Trailer Air Suspension Applications

The HD Value HDV9978 is intended for compatible trailer air-ride suspension systems using the S-28929 or W01-358-9978 air spring configuration.

Potential applications include:

• Hendrickson trailer air-ride suspensions
• Dry van trailers
• Refrigerated trailers
• Flatbed trailers
• Commercial freight trailers
• Heavy-duty semi-trailers
• Fleet trailers with matching suspension assemblies
• Other properly matched heavy-duty air suspension applications

Fitment Note: Trailer brand alone does not guarantee compatibility. Different suspension models may use air springs that appear similar but have different mounting plates, piston designs, air connections, and operating heights.

Heavy-Duty Rubber Bellows & Corrosion Protection

The HDV9978 features heavy-duty rubber bellows designed to handle repeated suspension movement and load changes.

The manufacturer's listed construction features include:

• Rubber bellows with a manufacturer-advertised burst pressure exceeding 300 psi
• Specially formulated rubber compound for ozone and temperature resistance
• Electroplated components for corrosion resistance
• Construction engineered around compatible OEM fit and function requirements

Note: Burst pressure is a material performance characteristic and must not be used as the air spring's recommended operating pressure. Always follow the suspension manufacturer's approved operating pressure and load specifications.

HD Value HDV9978 Air Spring Cross References

The following part numbers are associated with the HDV9978 replacement family in commercial truck and trailer parts catalogs:

• HD Value: HDV9978
• Hendrickson: S-28929
• Hendrickson: C-28929
• Hendrickson: S-29928
• Firestone: W01-358-9978
• Firestone: W013589978
• Continental / ContiTech: AS9978
• Continental / ContiTech: 67588
• Meritor: FS9978
• Automann: 566.ER9978
• Automann: AB1DK23I-A959
• Dayton Parts: 352-9978
• Triangle: AS-8959
• World American: WA01-9978C

Cross-Reference Warning: These numbers are provided for part identification and interchange research. Product configurations can differ across manufacturers and revisions. Confirm mounting dimensions, piston construction, air port location, ride height, and suspension application before purchasing.

Signs of a Failing Trailer Air Spring

Air springs are exposed to repeated suspension movement, road contaminants, changing loads, and environmental conditions. Over time, rubber bellows and mounting components may deteriorate.

Common symptoms of an air spring requiring inspection include:

• Visible cracks or dry rot in the rubber bellows
• Air leaks around the air spring assembly
• Trailer sagging or leaning to one side
• Suspension losing ride height while parked
• Damaged or corroded mounting components
• Excessive vibration or abnormal trailer ride quality
• Air suspension system repeatedly cycling to maintain ride height

Other suspension components, including air lines, fittings, height control valves, and shock absorbers, may produce similar symptoms. Inspect the complete suspension system before determining the required repair.

HD Value HDV9978 Product Specifications

• Brand: HD Value
• Part Number: HDV9978
• Listed Manufacturer Reference: SP 559978-KP
• Product Type: Suspension Air Spring
• Design: Single Convoluted
• Primary Application: Compatible Hendrickson Trailer Air-Ride Suspensions
• Maximum Diameter: 12.60 Inches
• Listed Height Range: 7.88 to 19.61 Inches
• Top Plate Diameter: 9.00 Inches
• Top Mounting Locations: 2
• Top Mounting Spacing: 5.50 Inches, Center to Center
• Air Connection Configuration: Top, Dual
• Rubber Construction: Heavy-Duty Bellows
• Cross-Reference: Hendrickson S-28929 / Firestone W01-358-9978
• Quantity: 1 Air Spring

Air Spring Installation & Fitment Verification

Before installing the HD Value HDV9978, verify the original air spring part number, suspension model, mounting plate dimensions, air connection configuration, and required operating height.

Inspect the air suspension system for worn mounts, damaged hardware, leaking air lines, faulty height control valves, and related components.

Critical Safety Warning: Air suspension systems contain pressurized components and may move unexpectedly when pressure is released or restored. Properly support the vehicle, follow the suspension manufacturer's depressurization procedures, and never work beneath a vehicle supported only by its air suspension.

Professional Installation Recommended: Commercial trailer suspension systems are safety-critical. Air spring replacement should be performed by qualified technicians following the manufacturer's approved procedures.