Download REMOVAL & INSTALLATION 1. Open air bleed valve on thermostat housing (if equipped). With engine off, using the appropriate, coolant add coolant to radiator until solid stream of coolant flows from air bleed valve, then close bleed valve. Fill radiator to base of fill neck. Fill coolant recovery reservoir to “FULL HOT” mark. Install coolant recovery reservoir cap. With radiator pressure cap removed, run engine until normal operating temperature is reached (radiator inlet hose hot). 2. With engine idling, Slowly add coolant to radiator until coolant level reaches base of fill neck and stay at a constant level at base of fill neck. Install pressure cap. Add coolant to recovery reservoir to “FULL HOT” mark. Add two engine coolant supplement sealant pellets (GM P/N 3634621) or equivalent. Install coolant recovery reservoir cap. Check for leaks. Coolant level in recovery reservoir should be check after thermo-cycle has completed (full hot-to-full cold). Add coolant as necessary. 3. If “LOW” coolant indicator comes ON or stay ON after start up, indications are that more coolant may be required. Check coolant level in recovery reservoir. Take appropriate action. NOTE: The “LOW COOLANT” warning/indicator lamp may come on after this procedure. After running engine so engine heats up and cools down 3 times. If the “LOW COOLANT” warning/indicator lamp still does not go out and coolant is above “FULL COLD” mark in reservoir assembly, there is a fault with the circuit. Troubleshoot and repair as necessary.