1994 Chevrolet Astro Owner's Manual - Page 247

Radiator Pressure Cap NOTICE: Your radiator capis a 15 psi (105 kPa) pressure-type cap and must be tightly installed to prevent coolant and possible loss engine damage from overheating. Be sure the arrows on the cap line up with the overflow tube on the radiator filler neck. When you replace your radiator pressure cap, an AC@cap is recommended. See "Service Replacement Part and Filler Recommendations" in the Index. Thermostat Engine coolant temperature is controlled by a thermostat in the engine coolant system. The thermostat stops the flow of coolant through the radiator until the coolant reaches a preset temperature. When you replace your thermostat, an AC' thermostat is recommended. 6-29