Cooling System/Cooling sytem deaeration COOLING SYSTEM DEAERATION CD30642 -UN-16JUN98 CD30643 -UN-04MAY98 Deaeration is normally accomplished by the jiggle pin (A) in thermostat flange area. However a pocket of air can stay on the top rear of engine. When refilling cooling system, loosen coolant temperature sensor or plug at the rear of cylinder head (B) to allow air to escape. CD,CTM125,165 -19-01DEC97 30 22 CTM3274 (01JUL99) 30-22 Saran Liter Engines 060799 PN=221