How to replace thermostat Chevrolet Avalanche — 2003 with 5.3L VIN T engine
Replace thermostat Chevrolet Avalanche
These step by step instructions show explain how to replace thermostat Chevrolet Avalanche 2003 with the 5.3L VIN T engine
Purchase a new thermostat
My personal preference is genuine GM or STANT. I am not a fan of the Murray Fail Safe products. I’ve had too many falsely fail in the full open position requiring replacement.
Drain the cooling system
Don’t try to drain the cooling system using the petcock on the radiator. These are plastic units that almost always break when you open them. If you’re lucky enough and yours doesn’t break, then it’ll most likely leak when you close it.
Instead, remove the hose clamp on the lower radiator hose and remove the hose. Let the coolant drain into a properly sized drain pan.
Remove the upper radiator hose clamp and hose at the water outlet
Use a hose spring compressor tool to remove tension from the hose clamp. Slide the hose clamp up on the hose so it’s out of the way. Then remove the hose and position it out of the way.
Remove the thermostat housing
Remove the three bolts holding the thermostat housing to the water outlet assembly.
Then remove the thermostat
The new thermostat should come with a new rubber O-ring. Do NOT install the thermostat without a new O-ring and don’t re-use the old O-ring.
Install the new thermostat
Install a new thermostat on Chevrolet Avalanche water outlet housing with the pellet section of the thermostat facing down into the water outlet assembly.
Place the thermostat housing over the thermostat and install the three hold-down bolts. Torque to 11/lb-ft. Do NOT overtighten!!
Refill cooling system and bleed air
©, Rick Muscoplat