Supplies Needed

• Floor Jack
• Jack Stands
• 1 Gallon Toyota Coolant (If you buy premix, you will need 2 Gallons)
• 1 Gallon Distilled Water (not needed if you buy premix)
• A Funnel
• A Bucket or Container at least 2 Gallons (not needed if you buy premix)
• Pliers

When to Change your Toyota Coolant

The dealership told me that the engine coolant should be changed every 30,000 miles.  This does seem a little frequent to me.  For the average driver’s mileage, this would mean that you will change your coolant about every 2-3 years.  Toyota requires a super long life coolant, which has preservatives in it to retain its properties for longer than normal.  I would use discretion when deciding to change your Toyota coolant.  If you are worried about a road trip in the summer and it has been a while since you have changed your coolant, then it is a good preventative measure.  Otherwise, I would defer to the advice of this article on cars.com.

How To Do It

1. Lift the vehicle

If you are unsure where the lift points are for your vehicle, consult your owners manual.  Always remember to use jack stands to support a vehicle that you are going to work under.

2. Open the Radiator and Reservoir

If you have just driven the vehicle, you will want to give it some time to cool before you attempt to open the radiator cap.  When the car is hot, the coolant is under pressure, and opening the radiator cap will find you covered with fluid that is likely near boiling.

To open the cap, press in (down) and turn.  Always do this slowly if you have doubts about the temperature of the coolant.  If you start to hear gurgling or hissing, stop and retighten the radiator cap and wait for the engine to cool further.
The coolant reservoir is on the right-hand side in front of the battery.  The cap for this does not twist off, but just pries off.  It is connected to the radiator by a small rubber hose that comes out the bottom of the reservoir and connects to the left side of the radiator inlet (visible in the previous photo).  No need to worry about opening this up

Assuming that there is coolant in the reservoir, this is a good time to verify the type of coolant that your car uses by peeking down into the reservoir.  There are two primary colors for Toyota.  Prior to 2004, generally use a red coolant, and after that use a pink coolant.

To replace  the coolant from the reservoir you will need to pull it out with a pump or a turkey baster, or remove the hose at the bottom of the reservoir, the latter of which will make a mess.  It will not drain out with the rest of the coolant from the radiator.

3. Drain the Radiator

The 2014 Toyota Sienna has a petcock on the radiator that you can see from the top.  You can see it in the above picture almost directly in the middle at the bottom of the radiator.  The valve is just a thin piece of plastic with little humps on either side.  If the exhaust is not hot, you can quite easily operate it from above the car.  If the exhaust is hot, then it is easy to reach the petcock from below.
There is a hole in the dust guard specifically for draining the radiator, so if you use the petcock, you will make less of a mess than removing the lower radiator hose.

The volume of coolant that you will remove is about 1.5 gallons, so you will need to have a suitable container to drain it into.
It will likely splatter a little bit as it is pouring down into your container.  I was able to significantly reduce the splatter by having the coolant drain straight into the drain hole of my drain pan.  It will take a while for the coolant to drain through that tiny hole, so while you are waiting, go ahead and proceed to the next step.

4. Mix the Coolant and Distilled Water

For most climates a 50/50 mix of water and concentrated coolant is recommended.  For colder climates, e.g. Canada or Alaska, you may want to bias the mixture toward a higher concentration of coolant up to 70/30 coolant to water.  I use a clean bucket as shown above and then put it back into the respective bottles that the water and coolant came out of, because it is easier to pour out of a bottle.

As to what type of coolant to use, Toyota sells a 50/50 mix of what they call “Super Long Life Antifreeze/Coolant“.  You would need to buy 2 Gallons of this Toyota Coolant to fill your car.  I was able to find Pentofrost A4 which is rated for newer Toyota engines with pink coolant, and then I just had to buy a gallon of distilled water to mix it with.

5. Close the Petcock

Once the coolant finishes dripping out, which can seem like forever, go ahead and close the petcock and/or reattach the lower radiator hose.  If you removed the hose from the bottom of the reservoir, then reattach it to and prepare to add coolant back into the system.

6. Fill the Reservoir and Radiator

The reservoir is easily filled, noting the marks on the right-hand side for Full and Low.  You will need to fill the radiator separately from the reservoir as coolant doesn’t flow naturally from the reservoir into the radiator.  When looking down into the radiator cap, you will notice that there are two different diameters.  It is easiest to fill if you have a funnel that fits the smaller diameter somewhat tightly.  The hole from the cap into the radiator is somewhat small, so it will take a while to get the approximate 1.5 gallons into the radiator.  Just be patient.  I recommend pouring with the bottle sideways or handle down, so that it doesn’t gurgle and splash as much.

It can be useful to squeeze the lower radiator hose every once in a while during the filling process to help get air out of the hose and fill it with coolant.  This hose comes out of the radiator on the lower left-hand side of the radiator and rises up about half way to the top of the radiator and into the engine.  It is about 2.5 inches in diameter and is fairly easy to squeeze.

As the radiator gets close to full, you may find that if you squeeze the lower radiator hose, that some bubble will come out and there will be more room to add coolant to the radiator.

 

7. Burp the Cooling System

The thermostat in the engine will not allow coolant to circulate through the radiator when the engine is below a certain temperature, so in order to get all the air out of the system, you need to start the engine and get it warmed up.  You will need to do this with the radiator cap off.  This is a lot easier if you use a funnel that fits well in the radiator cap throat, so that as the coolant expands or gurgles, there is somewhere for it to go other than out on the ground.  You may want to rev the engine a little bit to hurry the warming process along. 2500 rpms is a reasonable level to hold the engine at to help it warm up.

Once the engine is up to temperature (about 1/3 to 1/2 of the gauge on the cluster), you will want to squeeze the lower and upper radiator hoses on the left and right sides of the engine respectively to help circulate coolant and help get the air out.  As you do this you will want to take care to avoid the fans and exhaust components in the engine compartment.  You will notice that the hoses will firm up a bit and you will feel more resistance when they have coolant in them versus air.

Even after doing this and feeling the hoses firm up with fluid, there may still be some air in the system and it is worth regularly checking the level in the reservoir over the next few days to weeks as air will likely come out while the car is driven and jostled around.

8.  Close the Radiator and Reservoir

Once the system is burped sufficiently, make sure that the radiator is topped off and go ahead and replace the caps on the radiator and the reservoir.