How To: Drain and Fill Your Radiator

[MyNameIsThien]

Having recently drained and filled my radiator, I thought it would be a good time to do a write-up!

Items needed:

10mm wrench
Disposable gloves (highly recommended)
Lots of towels
Honda Long Life Type 2 Antifreeze/Coolant  (You can get this at your dealership.  I recommend printing out handaaccessories.com's price on the coolant so that your dealership can price-match like mine does)


Drain Pan preferably like the one pictured to make disposing of the coolant easier.  Don't be cheap either, the bigger the pan the better.


Get in the car, turn the key to the "ON" position but don't start the car.  Turn the heat on the hottest settings.

If you can fit the drain pan under your radiator without raising your car, you're golden.  That pan wouldn't fit under my car so I had to use the factory jack to raise the front a little.  

This is not necessary, but I recommend that you wear some disposable gloves like the ones they use at the doctor's office.  Once the car is raised with the drain pan under the radiator, open the radiator cap.  Be careful, have some towels around it because some fluid will leak out.  

Once the cap is off, look at the bottom of the radiator and in the very center you will notice a white plastic wingnut.  Unscrew it with your hands, it is easier to do this from up top then from the ground, and not to mention safer!

Now you have some options.  Unscrew the bolt a little and let the coolant drain slowly but in a controlled fashion.  I chose to remove the bolt altogether.  The coolant will gush out and spray all over the cross-member, the bottom of the front of the bumper and just get everywhere.  The coolant will leak out of various places and get all over your driveway so I recommend just letting it drain slowly unless your garage is sealed and easily cleaned.  

Even with the bolt removed as I had, it takes quite a bit of time for the fluid to drain completely.  You can help it along a little by squeezing the lower hose a little especially when it's getting to the part where it just drips out.  

Once all the fluid is drained, clean off the plastic wingnut, insert it back into the radiator, and hand tighten it.  

With a 10mm wrench, unbolt the single bolt holding the reservoir jug in place.  Unscrew the cap, pull out the long hose, and slide out the reservoir tank.  Drain it with the rest of the coolant.  You may want to clean out the exterior of the reservoir tank if you're a neat freak like me.  You can also wash out the tank with some tap water to get all of the old coolant out of it.  

Slide the reservoir tank back and tighten it back up.  Clean off the rubber hose and insert it back into the tank.  

With a proper funnel, fill the radiator all the way up and follow the instructions in the manual how to properly bleed out the system.  

If you're going to be using a drain pan like the one pictured above, getting rid of the old coolant will be a lot easier.  You will use at least an entire gallon of fluid so save the container and drain the old coolant into it.  You will need another container so that you can drain the remaining coolant.

Courtesy of Milan.

Pictures Added courtesy of Thien.

[AV6NHBP6SPD]

so how much coolant do you need to replace?  i bought 2 of those jugs couse i need to change mine but didnt had time yet. hope this week

[jobata23]

when would be the best time to replace the fluid? at 60k or when the fluid turns darker in color?

[AV6NHBP6SPD]

id say 60K. mine is at 70K now and i need to replace it, its doesnt cost much so better to replace it when honda tells you to

[Sworkhard]

Replace it at 60K.  Good coolant will protect your system from corrosion and won't gum up.  Worn out fluid won't necessarily.  Running until it starts turning black won't cause our cars to over heat as it doesn't gell up completely like dexcool does, but it's still a good idea to replace regularly.

If you have a gm that got 60k miles or more on it, get it out of there.  Flush the dexcool out with water, and replace it with the yellow stuff dodge and ford use (I forget the name, but it's also available at napa).

[jobata23]

^^^ thx fellas ill do it @ 60k

[MyNameIsThien]

Rule of thumb is once every 5 years or go by factory scheduled maitenance interval.

[jobata23]

^^ thx thien ill keep that in mind too

[clapton924]

I did this at 70k miles a few months back. It sounded sort of intimidating at first...but honestly it is extremely easy to do. Just make sure you have 2-gallons of the coolant...the I4 holds about 1.4 gallons if I remember correctly...I think the V6 is around 1.6 gallons.

[AV6NHBP6SPD]

would adding water wetter or purple ice be good idea? or just replace coolant?

[timot_one]

I'd replace it with coolant.  Not water.  You should be using a mixture of coolant and water with a 1:1 ratio.

[AV6NHBP6SPD]

I'd replace it with coolant.  Not water.  You should be using a mixture of coolant and water with a 1:1 ratio.

i got 2 jugs from honda, i think its premixed. i was talking about coolant additivie, i know two, one by royal purple, i think its called purple ice and other one called water wetter forgot who makes it

[CrackerTeg]

I'd replace it with coolant.  Not water.  You should be using a mixture of coolant and water with a 1:1 ratio.

i got 2 jugs from honda, i think its premixed. i was talking about coolant additivie, i know two, one by royal purple, i think its called purple ice and other one called water wetter forgot who makes it

Redline makes water wetter. I have a bottle sitting at home waiting to be poured in.

[cna]

i will take this project on am at about 70k better to be safe then sorry but i will thinking of draining the whole system and adding the blue stuff like the new Honda's is it safe?

[Jeff Likes Bagels]

Well, I bought 2 jugs of that stuff from Honda (well, according to the time it'd be yesterday). After work I'm going to drain the coolant and replenish it. They took off like 3 bucks for each one, and I didn't even show them the price from handa