How do you replace the thermostat located on a 2002 Toyota RAV4?

Answer 1

Follow the radiator return hose(Top hose connected to the radiator) This will lead you to the thermostat housing. It's usually bolted down with 4-5 bolts in the mid section of the motor. Make sure you pick up the gasket for the thermostat housing when picking up the thermostat. Some people don't use the gasket, instead they use the high temp gasket maker and seal it shut, works, but takes few blow with a mallet to break it open. recommended method is to use the gasket and thin layer of the gaket maker to insure no leaks. After bolting down the housing, you must wait atleast 45min-1hr to dry, enough to hold the seal, will completely cure overnight. Reconnect the radiator return hose to the thermostat housing, then fill the radiator with 50/50 Antifreeze/Water mixture. Distilled water is recommended for the mix, 25cents at the water vending machine per gallon or 69cents per gallon at the market. If you have the time to flush the cooling system, it is highly recommended. If your thermostat still opens up you can do the flush before changing the thermostat, if the thermostat isn't opening, you must do this after exchanging the thermostat. The flush liquid costs less than 5 bucks, drain your radiator, pour the liquid into the radiator and fill with water, run the car for 10min. with your heater full blast then drain,repeat this process until all the suds are gone and the water is clear. fill the radiator with antifreeze and now you must get all the trapped air out from your cooling system. You can easily do this by parking your car on a hill with the front end up, or use a jack and a jack stand if you have one leave the radiator cap off and start the engine, you will see bubbles, turn off the motor briefly after the radiator fan goes off, this is when the thermostat opens and hot coolant inside the engine gets returned into the radiator and replaced with cold coolant and when the temp reaches below the triggering point thermostat closes and the boiling coolant gushes out the radiator and it is hot enough to cause 3rd degree burns so turn off the motor before this happens and let the engine cool, do it again to insure all the air is pushed out the air caught in the thermostat or the engine. If your upper or lower hose looks pretty tired or the rubber started to crack, change the hoses with new, also inspect your radiator cap, if the rubber seal is cracked, springs rusted, get yourself a new cap.