Here's how to change your transaxle, radiator fluid.
I spent several days trying to figure out how to change the engine coolant and transaxle oil on our 2002 Prius. I've yet to receive a shop manual,but I figured that something as rudimentary as this would've surely had some decent instructions online somewhere. There were a few vague web sites, but nothing concrete.
So... Here's how you can do it ( for the classic Prius anyway)
Transaxle: It holds 5 quarts of Toyota T-IV transmission oil. I bought 6 because since you have to pump it into the transaxle case just like you would on a manual transmission, you will likely spill some, so its good to have extra.
Secondly, I bought a small transfer pump. I usually get the cheap-o disposable units for my Tacoma since I only change it every 100k or so, but these always leak and are a real mess. I got a better unit that had double the transfer capacity. I could transfer each quart in about 1 minute.
Now for getting the oil out. Using some of those drive-up ramps, slowly drive up onto them. I don't have a full ramp that would elevate the entire car, but that's ok since the transaxle has the plug at the rear of the pan, hence all the fluid will drain out at a back-leaning tilt- a clever fore site by the engineers. The transaxle is to the right side of the engine, if you were facing the front of the car. The drain plug is on the pan underneath, the fill plug on the front of the transaxle case. You will need to remove the front protective splash guard under the engine. Actually, it is in two pieces so you only need to remove the right side. It is simply held on with Phillips machine screws. Remove this and you will have access to both the fill plug as well as the radiator drain **** which we'll get to later.
Using a 24 MM wrench, lossen the TOP fill cap to the transaxle. No big deal if you don't, but there is back pressure within the case, so it is best to let the vacuum escape by loosening the fill plug first. Then loosen the drain bolt and let it drain. Surprisingly, the oil in this one was pretty durn clean. But it has 53,000 miles on it, so out it goes.
With that done, replace the drain plug, remove the fill plug and insert the end of the pump hose far enough into the opening as to not allow fluid to splash out. Then fill it up with the 5 quarts of oil. As expected, I spilled some, so I added a smidgen more from a 6th bottle. With the car up on ramps, the reading from the transaxle will not be level. But that's ok. We'll address that in a bit.
I read a lot about what differences there are between Toyota and other brands of coolant. Not much other than that Toyota claims their's is silicate-free. That and it is pink. Under normal circumstances I'd say screw it and be off to buy a gallon of Prestone long life coolant, which has worked dandy in my 210,000 mile Tacoma. But being a newer vehicle, I bit the bullet and bought the real Toyota stuff. I bought 2 gallons of pre-mixed Toyota SLL coolant. The stuff is twice as much as typical coolant. I usually keep an extra on hand because all cars tend to go through a little coolant over time.You will need to take the car off the ramps in order to drain all the coolant,but before you do that, look underneath the front of the radiator to your right facing the front of the car. You'll see what looks like a white plastic wing nut. That's the radiator draincock.Take the car down. Making sure that the engine is cool, remove the radiator cap and unscrew the draincock. The draincock is simply hand screwed in, so no tools required. The coolant will immediately shoot out, so make sure you have a large pan to collect it. The stuff will kill pets, so avoid spilling it and make sure the dogs/cats aren't hanging out while you do this.
The coolant on this Prius came out quickly initially, but then sat there and dribbled for about 30-40 minutes. It doesn't hold much, but I wanted to get all of the old 6 year old coolant out. I then usually get the hose and give it 2-3 short bursts of water through the filler neck. That will loosen/dislodge debris from the block/radiator. Make sure all the hose water drains out as it has minerals and other stuff in it.
Now fill the radiator with coolant. I also remove the reservoir tank and clean it out. After filling the radiator, fill the overflow tank. The cooling system will gradually 'burp' out air, so it doesn't hurt to add additional coolant to the reservoir tank to anticipate this. I had maybe a quart left of the gallon, so I put what remained in the trunk. When I drive it to work, the air will likely come out of the coolant system, therefore I can put the rest into the reservoir and it will be done.
Lastly- checking the level of the transaxle. Remember that?Well now that the car is on level ground,we can check it accurately. Anyway, place a pan under it, pull the FILL plug, and see if any fluid drains out. Mine did just a bit. When it stops draining,then you know at that point that the transaxle fill is now level.
That's it! Anyhow, after my experience yesterday, I find that for the engine oil, plugs, transaxle, radiator coolant, and air filter, it isn't all that different from a normal car and hence perfectly capable of being serviced by the average DIYer. Hope that helped.[attachment=0:2ozknucz]drip_drip.jpg[/attachment:2ozknucz]