1995 GMC Jimmy Owner's Manual - Page 264

Radiator Pressure Cap 1 NOTICE: Your radiator cap is 15 psi (105 kPa) pressur+type cap and a must be tightly installed to prevent coolant loss and possible 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, aGM cap is recommended. See "Service Replacement Part and Filter 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. 6-24