Unity 65390c Rear Conversion Kit Brake Repair Tool

Target Vehicles

This Unity 65390c rear conversion kit is designed for 1985-1999 Cadillac Deville, 1986-1999 Buick LeSabre and 1986-1998 Oldsmobile and Pontiac models listed in the fitment data. It converts the original air-ride suspension to a passive steel-spring setup for owners who want to eliminate air-system leaks and compressor failures. The kit suits DIYers and shops looking for a permanent, maintenance-free rear suspension solution on these specific GM platforms.

Installation Notes

Unity states the kit is engineered for a trouble-free installation using existing mounting points on the listed vehicles. No welding or fabrication is required, but the air lines, compressor and height sensors must be removed or deactivated during the swap. Installers should verify the correct spring rate for the exact model year because the fitment spans 1985 through 1999 and spring specifications can differ across that range.

Long-Term Behaviour

The steel springs and matched shocks replace the air bags and electronic controls, so ride height stays constant regardless of load or temperature changes. There is no compressor to cycle, no air lines to crack and no height sensor to fail, which removes the common failure modes of the original system. The passive design delivers consistent damping and spring rate over the vehicle's remaining service life without the pressure loss that affects air suspensions over time.