Suncoast Converters Trans Brake Kit - Reversed Pattern PRN123 COA-22020

The Coan Racing COA‑22020 Trans Brake Kit (Reversed Pattern PRN123) is a performance-grade hydraulic upgrade for Turbo-Hydramatic 400 transmissions, engineered to offer drag racers precise launch control through a reversed PRN123 shift configuration. Designed as a fully manual valve body conversion, this kit replaces the factory shift control with driver-directed engagement and includes a high-quality solenoid, machined brake valve, springs, and accumulator upgrades to maintain firm line pressure during high-load conditions. As a safety feature, the transbrake functionality is limited to first gear, preventing accidental reverse application while allowing powerful launch setups. Installation instructions detail the necessary modifications—such as drilling a 1/16" bleed orifice in the direct drum, replacing clutch springs, and modifying the servo and modulator circuits, to ensure full transbrake operation. The kit plugs directly into the OEM TH400 valve body bolt pattern, making for a clean, efficient installation. Wiring is straightforward and includes a momentary switch and solenoid, enabling on-demand brake control for staging. Overall, the COA‑22020 offers a robust, competition-ready transbrake solution for serious performance builds.