1995 Cadillac Seville Owner's Manual - Page 258

1. You can remove the coolant surge tank pressure cap when the cooling system, including the coolant surge tank pressure cap and upper radiator hose, is no longer hot. Turn the pressure capslowly to theleft until it first stops. (Don't press down whileturning the pressure cap.) If you hear a hiss, wait for that to stop. A hiss means there is still some pressure left. 2. Then keep turning the cap,but now push down as you turn it. Remove the pressure cap. 5-19