[MrRangerZr1]

EDIT 10/2021
Updated with videos:

Original post:
Hey folks,

I did a coolant drain and fill on my 2010 EX-L. It is not difficult at all. If you can change your own oil, you can do this as well.

Steps

1.Make sure that the engine is cold. DO NOT open the radiator cap if the engine is hot.

2. Unscrew the radiator cap and install it lightly over the radiator, this makes sure that you don't get any debris in your radiator.

3. Now go underneath the van, place a drain pan below the radiator and remove the petcock. Don't remove the plug all the way out, just enough were the coolant starts to drain.

4. Clean the petcock and reinstall. Don't tighten it like a bolt, once it stops turning stop there. just make sure its not loose.

5. Now on to the coolant reservoir. Remove the two 10mm bolts and unscrew the overflow hose. Carefully wiggle out the reservoir with the reservoir bracket out of the van.

6. Clean the reservoir with a hose to flush out any debris.

7. Reinstall the reservoir and reservoir bracket and tighten the 10mm bolts. Don't tighten the bolt too much. If you strip the threads on the radiator, well.....you need a new radiator.

8. Now fill the radiator with coolant until it fills up. Fill the coolant reservoir between the MIN and MAX lines and screw the hose back on.

9. Before you start the van, you can squeeze the upper radiator hose if you want to to release any trapped air.

10. Turn the AC settings to HI before starting the van up. Start the van up without the radiator cap installed. Let it idle till the radiator fan kicks on 2-3 times or just wait till it reaches operating temperature. You can also give the van few revs. Top off the coolant if it gets low.

11. Before installing the radiator cap, check the coolant reservoir and top off as needed.

12. Install the radiator cap and go for a ride. Make sure the van is not overheating. Also make sure the heat is working too.

13. Drive back and let it cool down.

14. After it cools down, check the radiator and coolant reservoir and top off as needed.

15. You may have to repeat steps 14 and 15 to make sure the coolant isn't low.


And that's basically it. Just make sure to check the coolant levels a week or two after you drained the coolant. Keep in mind this method doesn't completely drain the whole system, but it gets out majority of the coolant.

 

[kck3888]

I was told that there is a second drain bolt in the back.

 

[MrRangerZr1]

You missed the second drain bolt in the back.

There is a reason why I made the last sentence bold.

 

[MrRangerZr1]

.

 

[lucio]

the majority of the challenge is locating the petcock, it is a white plastic under the radiator, and you should be able to reach it without taking off the lower splash shield/the big piece of plastic.

the petlock could be very tight if nobody ever unlocked it.

 

[MrRangerZr1]

the majority of the challenge is locating the petcock, it is a white plastic under the radiator, and you should be able to reach it without taking off the lower splash shield/the big piece of plastic.

the petlock could be very tight if nobody ever unlocked it.

Yes it can be challenging. I luckily got it off with no problems. In the tight space, fitting a pair of pliers to open the petcock would be extremely difficult.

 

[davedrivesody]

Keep in mind this method doesn't completely drain the whole system, but it gets out majority of the coolant.

+1 There's no easy way to completely drain the coolant. (e.g. rear heater)

That's why the replacement intervals after the first are shortened by half.

Dave

 

[DrD]

The block drain on the rear of the engine is pretty easy to get to - highly recommended when changing the water pump, etc. to prevent making a mess. I prefer to hit both - if you are changing the coolant, might as well get as much out as you can (as pointed out above, you won't get everything, but you can get pretty close - about a half gallon is left in the system once you drain the radiator, overflow tank, and the engine)

 

[planomateo]

Great post!

 

[jp233]

I think on step 10, you mean turn the HEAT up to high in both the front and rear HVAC controls. You want to circulate the coolant to the heater cores and get the air out.

You can also try to fill some coolant from the upper rad hose, turn it up and use it like a funnel, which helps put less air in the system to begin with (vice filling the entire thing from the radiator). But, that big ole plastic cover would need to come out.

Burping the rad hoses always helps, too, you just have to do that before you get the radiator filled nearly to the top because you will raise the level when doing so (i.e. spills coolant when you squeeze it)

 

[kck3888]

The block drain on the rear of the engine is pretty easy to get to - highly recommended when changing the water pump, etc. to prevent making a mess. I prefer to hit both - if you are changing the coolant, might as well get as much out as you can (as pointed out above, you won't get everything, but you can get pretty close - about a half gallon is left in the system once you drain the radiator, overflow tank, and the engine)

Where exactly is this second drain plug?

 

[John Clark]

Where exactly is this second drain plug?

http://www.odyclub.com/forums/52-2005-2010-odyssey/121122-coolant-change-drain-procedure.html

 

[jnissen]

I've done a couple timing belt replacements over two Odysseys and no matter if the block is drained I still get a splash of coolant when the water pump is removed. The last one I only drained the radiator then put down a large beach towl (old ones) to capture the mess. Honestly was not that bad. A lot quicker.

Sent using Tapatalk

 

[DrD]

Where exactly is this second drain plug?

It's on the passenger side of the engine - you go through the wheel well and look on the back of the engine a little higher than the base of the part the oil filter screws onto. It looks like a bolt with a small tube coming out of the center of it. You loosen that, and coolant will come out of the tube (so place a tube over it - doesn't have to be a very snug fit, just hold something over it while it drains.

The first time I changed the timing belt, I didn't undo it and had a bunch of coolant come out when I removed the water pump (maybe seemed like more since I was expecting a little, but not a ton gushing out!) - second time, I drained the block, and when I removed the water pump, pretty much the only coolant that came out was what was actually in the water pump (just a little bit) - is it necessary - no, but it does keep the mess down and prevents getting the crank position sensor wet (it didn't look really water tight, and I was worried about it the first time around).

 

[ldavid008]

About how much coolant is needed to do the drain and fill on an '08?

 

[MrRangerZr1]

About how much coolant is needed to do the drain and fill on an '08?

You need 2 gallons of type 2 Honda coolant. You won't use all of the 2 gallons, you will have maybe 1/2 a gallon left over.

 

[Klank06]

On step 10 did you mean the front & REAR heating controls ? I think if you do not turn on the REAR heating controls you will be about 48 ounces low . What does the factory service manual state ?

Hey folks,

I did a coolant drain and fill on my 2010 EX-L. It is not difficult at all. If you can change your own oil, you can do this as well.

Steps

1.Make sure that the engine is cold. DO NOT open the radiator cap if the engine is hot.

2. Unscrew the radiator cap and install it lightly over the radiator, this makes sure that you don't get any debris in your radiator.

3. Now go underneath the van, place a drain pan below the radiator and remove the petcock. Don't remove the plug all the way out, just enough were the coolant starts to drain.

4. Clean the petcock and reinstall. Don't tighten it like a bolt, once it stops turning stop there. just make sure its not loose.

5. Now on to the coolant reservoir. Remove the two 10mm bolts and unscrew the overflow hose. Carefully wiggle out the reservoir with the reservoir bracket out of the van.

6. Clean the reservoir with a hose to flush out any debris.

7. Reinstall the reservoir and reservoir bracket and tighten the 10mm bolts. Don't tighten the bolt too much. If you strip the threads on the radiator, well.....you need a new radiator.

8. Now fill the radiator with coolant until it fills up. Fill the coolant reservoir between the MIN and MAX lines and screw the hose back on.

9. Before you start the van, you can squeeze the upper radiator hose if you want to to release any trapped air.

10. Turn the AC settings to HI before starting the van up. Start the van up without the radiator cap installed. Let it idle till the radiator fan kicks on 2-3 times or just wait till it reaches operating temperature. You can also give the van few revs. Top off the coolant if it gets low.

11. Before installing the radiator cap, check the coolant reservoir and top off as needed.

12. Install the radiator cap and go for a ride. Make sure the van is not overheating. Also make sure the heat is working too.

13. Drive back and let it cool down.

14. After it cools down, check the radiator and coolant reservoir and top off as needed.

15. You may have to repeat steps 14 and 15 to make sure the coolant isn't low.


And that's basically it. Just make sure to check the coolant levels a week or two after you drained the coolant. Keep in mind this method doesn't completely drain the whole system, but it gets out majority of the coolant.

 

[MrRangerZr1]

Yes, front and rear. Manual states 1.85 gallons including the coolant reservoir.

BTW, You could have just quoted step 10 instead of the whole post.

 

[Nihonjin]

So I did a coolant drain and fill today on my 2011 Honda Odyssey EX-L (160k miles). It was my first time doing it myself (can’t remember when I had it done last time at the shop but pretty sure this wasn’t the first time the car went thru it). Anyway, after doing the drain and fill, I noticed a few things and I wanted to check if any of them were normal:

- I ended up using < 1 gallon of Honda coolant. Most places (including this post) states that you tend to use about 1.5 gallons so I’m wondering how I could’ve only gotten about 2/3 the coolant out. I did wait till the coolant stopped draining before plugging It back.

- During the fill, I was using the spill proof funnel kit and I followed YouTube tutorials that said to pinch the radiator hose to “burp” the line and get out air. As I let the car run for a while, there was consistent bubbles constantly emerging into the funnel and pinching on the hose introduced more bubbles. And there was never a point when there were no bubbles within a few second span. I’m wondering if that‘s normal too? I assumed the bubbles/air would be gone from the lines after a while?

In the end, things seemed fine with the car as the temperature gauge is normal and nothing seemed out of the ordinary from driving it around.

 

[davedrivesody]

I ended up using < 1 gallon of Honda coolant

Did you drain the engine block in addition to the radiator? If not, that could explain the shortfall.

The engine block drain bolt is located on the rear of the block, on the right (passenger side). It has a 12mm head with a nipple onto which you can attach a 5/16" rubber hose to direct the outflow into a container.

Small air bubbles will be forced out through the overflow tube when the engine gets hot. As long as you have purged the big air pockets, the system will stabilize itself. Since your temperature gauge is reading normal, I suspect that all is well.

Check the overflow tank regularly for a while. The system will draw coolant from the tank as it cools down to replace any expelled air bubbles. Its level could drop a bit.

Speaking of the overflow tank, it should be emptied, rinsed, and refilled with fresh too.