Description
Maintain optimal chassis ride height and restore OE damping stability across your commercial fleet with the genuine ContiTech 4912 N Complete Air Bag Suspension Assembly. Engineered specifically for heavy commercial truck rear drive axles, lift axles, passenger transit buses, and multi-axle freight trailers, this OE-grade factory-assembled air spring combines a high-strength steel top plate, flexible rubber sleeve bellow, internal rubber bump stop, and composite piston base into one bolt-on unit. Surface rubber cracking, fabric cord fatigue, leaking top rim seals, or damaged mounting studs cause continuous pressure loss, severe vehicle sagging, accelerated shock absorber wear, and dangerous cargo bounce. This original ContiTech 4912 N complete air bag assembly solves those suspension air-leakage and structural failure points directly. It features multi-ply cord-reinforced elastomer construction, electrophoretic anti-corrosion coating, precision-machined air inlet ports, and OE mounting stud geometry to deliver leak-free air containment, superior load support, and uncompromised transport availability.
Technical Parameters
| Category | Specifications & Technical Details |
| OE Factory Pre-Assembled Complete Unit | We press-fit the steel top plate, reinforced bellows, and base piston into one assembly at the factory. Technicians skip on-site assembly and bolt it straight to the frame and axle. |
| High Burst Pressure & Pneumatic Containment Capacity | We build the bellows to hold continuous high-pressure air. It stays stable at rated pressure and under extreme pressure spikes, so sudden rupture does not occur. |
| Multi-Axis Articulation & Dynamic Displacement Compensation | We optimize the sleeve wall curvature so the bellows extends smoothly and deflects through large angles during cornering, climbing, and uneven-road driving. The upper and lower bases avoid shear stress damage. |
| Integrated Air-Inlet & Heavy-Duty Mounting Studs | We fit a high-strength threaded air inlet and fastening stud into the top plate center. One component supplies compressed air and clamps the frame, with zero high-pressure leakage. |
| Integrated Internal Rubber Bump Stop Cushion | We build a high-density rubber bump stop into the assembly. It protects the top plate and base during extreme compression or low air pressure, so metal parts never strike each other directly. |
Applicable Car Brands & Models
Common warning symptoms include:
Continuous Vehicle Sagging Overnight: The air spring loses air pressure when parked, causing the truck frame to tilt on one side.
Visible Rubber Surface Cracking or Cord Exposure: Deep ozone cracks along the rubber bellow curvature or exposed inner fabric cord layers.
Audible Air Leakage from Top Plate Seals: Soapy water reveals air bubbles around the top plate crimped edge or air inlet stud.
Severe Chassis Bounce or Bottoming Out: The truck rides uncomfortably rough due to complete loss of air spring dynamic pressure.
A complete factory-assembled unit includes a pre-crimped top plate, new internal bump stop, fresh lower piston base, and factory-tested air sealing. Installing a complete assembly eliminates the need for expensive crimping tools, prevents improper seal alignment, and significantly reduces fleet installation downtime.
Premature failure is typically caused by driving continuously with failed shock absorbers (causing excessive over-extension), oil/grease leaks from nearby axle seals degrading natural rubber, or heavy road salt corrosion weakening top plate crimping edges.
Our 1-year warranty covers all rubber cord delamination, top plate seal crimping leakage, mounting stud shearing, piston base structural cracking, and manufacturing defects under normal operating conditions. If an assembly fails within 12 months, we provide prompt replacement or warranty processing upon inspection.
