Originally Posted By: LeakySeals
Your 04 Corolla uses Toyota Long Life (Red) coolant. The Super Long life (Pink) coolant was not used until 05+. Toyota Red LLC is sold as concentrate meaning it has to be mixed 50/50 with distilled water prior to use. Once you do that, you have 2 gallons of coolant to use. It makes Toyota Red 1/2 the cost per gallon as the the Pink coolant.
Toyota has specific requirements for coolant. No 2-eha (dex-cool). No silicate (some HOATs like G-05, green, etc). As stated above, your Toyota uses the Red LLC coolant concentrate. Once diluted 50/50 with distilled water from the grocery store, the cost per gallon will be approx $15. There is an alternative coolant sold at Napa called "Zerex Asian Vehicle Antifreeze/Coolant". Its premixed, also $15 a gallon.
Sticking with the requirements will allow you to perform a simple drain and fill. A drain and fill on a Toyota is as easy as changing the oil. It will get 90% of the coolant and will be good for 60k. The drain will be approx 4qts + the drain, clean and fill of the coolant expansion tank. A flush is not required because of the coolant Toyota uses. There is no heavy silicate, no 2-eha sludge to flush from the system.
Locate the hand tight plastic radiator drain plug located at the bottom right of the radiator. The radiator has a drain funnel. So your only going to loosen the drain plug until coolant flows, you will not fully remove it. Not fully removing the drain plug will force the coolant down the funnel into a waiting container rather than splash all over the place. Takes about 15 mins to drain. I go straight to a container like a plastic milk jug. That will require jacking the car up slightly to make room for the jug. But you can use your oil drain pan if you want.
The procedure is simple. Open the radiator cap, loosen (but don't remove) the radiator drain plug, let the coolant out into your container of choice. The container should be 4qts or more otherwise you need to monitor drain to change containers to prevent spill.
While its draining remove and clean the expansion tank and its cap in the sink. Put it back on and fill to the full line with coolant.
When the radiator has finished draining close the hand tight drain plug. Refill the radiator till its full. Important step Here. Your going to start the car with the radiator cap off to "burp" the air out of the system. Keep the cap in your hand ready to put back on. Start the car. add coolant if necessary. As the engine begins to warm, the coolant will expand and begin to rise. Just before the coolant begins to overflow, put the radiator cap back on. Now that the radiator cap is back on let the car run until the temp gauge rises to the middle and stabilizes via thermostat opening. In a day or so top off the expansion tank. The system may draw some additional coolant in which is normal. After that expect some minor coolant loss which is normal.
I prefer buying the Toyota Red LLC not only because I think its a good coolant, but because I end up with 2 gallons after the mix. This allows me to top off the expansion tank between 50-60k drain and fills.
What he said ^^^^^^ This is what I do for my Toyotas as well.