How to replace the thermostat on a 1989 GMC Sierra
Drain the coolant (left lower side of the radiator) Follow the upper radiator hose to the engine, at the end of the hose is a metal housing, held down with 2 bolts, or 1 bolt and 1 stud. There may be wires going to one of the bolts, be sure these go back on. After taking the 2 bolts out, lift up the housing and the thermostat will be right there. Clean the old gasket from the manifold and the water outlet housing. Now install the thermostat, then the gasket. and torque down the bolts evenly. about 25-30 ft pounds. fill the radiator until about 2 inches below the filler neck, and start the engine, now keep putting coolant in to keep it 2 inches below the radiator neck, and let it warm up until you see coolant moving in the radiator, now fill it to the top and fill the coolant bottle to the cold mark. Its a good time to replace the radiator cap also. Good Luck.
Jan 28, 2010 |
1989 GMC Sierra