1994 GMC Suburban Owner's Manual - Page 285

Radiator Pressure Cap-Gas Engines The radiator pressure cap must be tightly installed with the arrows on the cap lined up with the overflow tube on the radiator filler neck. NOTICE: Your radiator capis a 15 psi (105 kPa) pressure-type cap and must be tightly installed to prevent coolant loss and possible engine damage from overheating. sure the arrows on the cap Be line up with the overflow tube on the radiator filler neck. 6-39