Filling the cooling system

[nswst8]

It seems that alot of you are having issues with your cooling system, and it seems that 90% of those issues are the result of air in the cooling system.

This is the Honda procedure for filling the cooling system.

1. Set the heater temperature lever to maximum heat.

2. When the radiator is cool, remove the radiator cap and drain plug, and drain the radiator.

3. Reinstall the radiator drain plug and tighten it securely.

4. Remove drain and reinstall the reserve tank. Fill the tank halfway to the MAX mark with water, then up to the MAX mark with coolant.

5. Mix the recommended anti-freeze with an equal amount of water, in a clean container.

6. Loosen the air bleeder bolt in the water outlet, then fill the radiator to the bottom of the filler neck with the coolant mixture. Tighten the bleeder bolt as soon as coolant starts to run out in a steady stream without bubbles.

7. With radiator cap off, start the engine and let it run until warmed up (Fan goes on at least twice). Then, if nessasary add more coolant mix to bring the level back up to the bottom of the filler neck.

8. Put the radiator cap back on, then run the engine again and check for leaks.


Now if you are using the premixed anti-freeze just fill as directed.

Honda OEM thermostat nessasary to properly bleed the cooling system. (Drill hole in aftermarket thermostat in same spot as honda OEM).

[Dr_Snooz]

Good write up.

So here's a question for you. When I bleed my system, coolant never runs out of the bleeder bolt until I start the engine. Then it shoots all over the place. Any thoughts? (Car is on level ground).

[Pico]

Good write up.

So here's a question for you. When I bleed my system, coolant never runs out of the bleeder bolt until I start the engine. Then it shoots all over the place. Any thoughts? (Car is on level ground).

Aftermarket or OE thermostat. Most aftermarket T-Stats dont have a bleeder hole on them. The OE ones do so this may be the reason you are not getting any coolant thru the bleeder.

[Dr_Snooz]

Good point. I'll make a note to check that when I have it open next. Oddly enough, I have two Hondas (3g & 4g) doing it. Thanks Pico!

[DBMaster]

I have never been able to get coolant to flow from the bleed bolt unless the engine was running. It may be that the thing is too high up in relation to the radiator, or maybe because my driveway slopes. I just crack it open enough to let coolant out without spraying up in the air. Never had any coolant issues.

[MessyHonda]

this thread made me go buy a new fan switch because i had my fans jumped...and now that i did it...i blew a small hose for the intake...lol il guess il have to redo my cooling system again.

[nswst8]

this thread made me go buy a new fan switch because i had my fans jumped...and now that i did it...i blew a small hose for the intake...lol il guess il have to redo my cooling system again.

A small what? Where?

[MessyHonda]

a hose that goes from the water pipe to the intake manifold...i got it fixed today tho...fresh coolant and just bled

[russiankid]

Just for piece of mind, replace every coolant hose that these cars have. Its worth it, I don't even worry about a hose busting anymore.

[DBMaster]

Just for piece of mind, replace every coolant hose that these cars have. Its worth it, I don't even worry about a hose busting anymore.

Not a bad idea. Mine has blown two and both were very short pieces of heater hose that connected sections of metal tubing. A couple of them are very hard to access. I also had a small hole in the heater hose that connects underneath the distributor. I didn't have hose on hand so I just cut off about 1/2" and reconnected it. The part of the hose that was oil soaked from a leaky distributor o-ring failed, but the remainder of the hose is in good shape.

[nfs480]

What direction does the petcock on the radiator turn? I've been told counter-clockwise and clockwise by different people and I don't want to break it. Also, has anyone ever removed the coolant drain plug in the block before? I'm planning on draining everything and refilling with Honda blue coolant and i'm gonna replace both the thermostat and the thermo sensor in the radiator tomorrow. Anything important I should know? And do I need to lubricate the T-Stat gasket with anything?

[russiankid]

Not a bad idea. Mine has blown two and both were very short pieces of heater hose that connected sections of metal tubing. A couple of them are very hard to access. I also had a small hole in the heater hose that connects underneath the distributor. I didn't have hose on hand so I just cut off about 1/2" and reconnected it. The part of the hose that was oil soaked from a leaky distributor o-ring failed, but the remainder of the hose is in good shape.

Yes some of those hoses are a PIA to get to. However, once its all done, you forget about them.

[nswst8]

Yes some of those hoses are a PIA to get to. However, once its all done, you forget about them.

Amen, I replaced all my hoses acouple of years back.

[w261w261]

I didn't drain the block, just the radiator. I believe the petcock has a regular right-hand thread on it. First, I drained the radiator. Then refilled with distilled water and ran until the thermostat opened so the liquid circulated around. I repeated that cycle 3 or 4 times, by then I was pretty sure the car had just the distilled water in it, at any rate it looked clear.

Then I refilled the radiator with uncut coolant, ran it until the thermostat opened and the block and radiator mixed. Then I tested it with a coolant tester, which showed I wasn't at the 50-50 mix ratio yet. So I dumped the radiator again and again refilled with 100% uncut Peak (I like Peak because it's bright green, which allows me to see the level in the tank better). I think then it was the right ratio.

You should use a tester especially because you live in an icebox. In mine, the color looked ok, but the mixture definitely wasn't.

Also, this process can dump a lot of coolant onto the ground. Wash it off very carefully and completely with a hose. Ethylene Glycol is big poison to dogs, who go for it because it's sweet.

[nfs480]

Yeah, luckily my boss is letting me use one of the bays to work on it tomorrow and we have a coolant tester in the shop. I'm still gonna try to drain the block because i'm worried about rusting with this well-water we have out here.

[Dr_Snooz]

I'd say those bypass hoses are a 150k mile maintenance item. I got to about 175k miles and lost one on the freeway at rush hour. Aside from feeling like a fool, I got to take half the car apart in my suit to fix it.

[nfs480]

I had a heater hose blow out on me on the interstate at night. Luckily I had AAA. Really should replace the rest of the hoses though.

[w261w261]

Yeah, luckily my boss is letting me use one of the bays to work on it tomorrow and we have a coolant tester in the shop. I'm still gonna try to drain the block because i'm worried about rusting with this well-water we have out here.

Negative on the well water. Go to the grocery store and get a few gallons of distilled water. The minerals in well water will hasten the rust and schmutz forming in the coolant mix. It's a little more work this way, but definitely worth it.

[w261w261]

Yes some of those hoses are a PIA to get to. However, once its all done, you forget about them.

Awhile back, I replaced what I thought were all the little hoses that go to the idle stabilizer and IACV. I bought them from Honda, as they are different diameters and some have preformed curves. What I didn't do, was logically think of where the water goes, to make sure I got both ends of the transaction, so to speak. I missed the hose that goes from the exit of the IACV, and tucks under the intake manifold. It was the original hose I'm sure, and had a bad case of swelling at the ends. It's my candidate for the PITA hose installation.

[Dr_Snooz]

Awhile back, I replaced what I thought were all the little hoses that go to the idle stabilizer and IACV. I bought them from Honda, as they are different diameters and some have preformed curves. What I didn't do, was logically think of where the water goes, to make sure I got both ends of the transaction, so to speak. I missed the hose that goes from the exit of the IACV, and tucks under the intake manifold. It was the original hose I'm sure, and had a bad case of swelling at the ends. It's my candidate for the PITA hose installation.

On the FI engine at least, the hands down winner is the one that sits under the intake manifold. I had to remove the throttle body to get to it. That was bad enough, but the throttle body uses the only paper gasket I've ever seen on a Honda. I spent an hour with gasket remover spray and a gasket scraper getting the old gasket off. Egad what a hassle. Then a piece of the air intake hose broke, so I got to replace that too.

[nfs480]

When draining the radiator do you need to remove the splash guard? Because I can't get mine off, the bolt have rusted too much. There's an opening in the splashguard where I can see the petcock on the radiator, will the coolant flow through that or does it spray out with more force?

[import racer]

just put about 6 inch piece of hose on it and it hang down through the hole into a drain pan.

[nfs480]

lol, guess I didn't do it right. I got coolant everywhere. Although I did find out I have an aftermarket radiator which is probably different from the Honda one in terms of petcock design.

[DBMaster]

I made the hole in my splash pan larger with a utility knife years ago so I could drain the radiator without removing the pan. I would call the a design flaw, actually. It's easy to cut the hole and it saves a lot of time over the life of the car.

[nfs480]

Yeah, i'll probably do the same thing. I tried to remove the splash guard but the bolt just kept spinning and wouldn't come out.