Filling the coolant after rebuild...
 

I am actually wondering, I added as much coolant as I could into the radiator... but it wasn't near what I expected from the recommended filling / capacity in the FSM.

When I ran the engine, I only had enough time to run it for a few minutes before I had to turn it off... due to MINOR coolant leaks... nothing like SPEWING out.

But about 5 seconds before I turned it off, the BUZZER went off... you know, the low coolant buzzer!

So this time how do I add the rest of the coolant? Add it to the overflow tank or what?

--Gary

I usually use my hand to cover the filler hole, then I "pump" the upper rad hose to help distribute the coolant. Disconnecting the highest hose at the throttle body also helps, and you have to pour SLOWLY.

I did that about as much as I could... but I suppose I could always go SLOWER! hah...

How do I know it's full?

--Gary

I fill it until it won't take any more. If you fill from the highest point (funnel and throttle body hose) it helps get out all the air bubbles.

You can also start the engine cold and fill it with the car running, but this takes some practice. And make sure to keep the overflow container full as well.

I was out there earlier, it's raining now... (damnit) or else I'd start it up.

I kept on putting water into the neck, sealing with my hand, pumping with the upper hose and repeating.

After a while I realized the coolant resivoir is almost COMPLETELY full. lol

I'm guessing that the system is full right? ;P

--Gary

did you burp the system with the air bleeder valve? Did you blast the heater to kill all the bubbles too?

-Andrew

Nope, want to explain both please? (Well, the bleeder valve at least... heater sounds obvious)

I can't start the car right now... the hood is just sitting on top of the engine bay to keep the rain from getting in lol.

I started it for a second and it sounded like it flooded out and stalled. *sigh* Hopefully just normal starting problem and not something serious... I'll see when it stops raining, if that happens. =/

--Gary

Um on your radiator theres a plastic screw that you have to open up and it lets the air release and lets all the coolant flow, fill it up again till the brim and then "burp" it with the air bleeder valve until coolant comes out of that thing. Then tighten it, fill it up.

After that is done have the radiator cap off, and the heater ready at full blast, then the coolant should go down, fill it up, put the cap on and the system should be full.

-Andrew

1988 GTU "Thats how i do it ;) "

Ahhh... see here's the problem... I was searching through the FSM for an air bleeder valve... but I think I know what's wrong...

I don't think it exists on an S5... lol. I think what you're talking about is that valve where the upper rad. hose connects to the water pump... well S5s don't have that valve.

The FSM says to run the car at idle with the fill cap off to let the air out... but I'm not sure how to do that since I've got to be IN the car holding the gas down.

--Gary

by fill cap you mean radiator cap right? just take it off and put it aside, you only need one person. so s5's don't have that bleeder valve? i learn a new thing everyday..

-Andrew

Well don't take my word on it! I'm just guessing 'cause I can't find it anywhere in my FSM or car haha...

--Gary

Here's the procedure I recommend, based on the info in the FSM and successfully doing this dozens of times over the years.

1. Make sure both the engine and radiator drain plugs are installed. Obvious I know...
2. Remove the filler cap (on top of thermostat housing), radiator cap and (on S4's only) the bleeder on the side of the top radiator neck.
3. Begin filling the water/coolant mix through the radiator neck until it reaches the top, then replace the radiator cap.
4. For S4's, continue filling through the filler neck until the bleeder overflows, and replace the bleeder cap. Don't overtighten it or you'll ruin the plastic plug.
5. Continue filling though the filler neck until the water/coolant reaches the top.
6. Start the engine and let it idle. The water level will probably drop a bit when the engine starts as the pump pushes the water into air pockets. Keep topping up the system as necessary.
7. Keep the engine running until the thermostat opens. You can tell when this happens as there might be another drop in water level, and the top radiaor hose will start to warm up.
8. When no more air bubbles are appearing in the filler neck, replace the filler cap.
9. Fill up the overflow bottle to the correct level.
10. Go for a test drive, keeping an eye on the temp gauge. Make sure the engine reaches full operating temp.
11. On your return, once the engine has cooled down, recheck the level at the filler cap (not the radiator cap) and the overflow bottle.

I have not once had a low coolant warn after performing this procedure. :)

12. make sure the heater blows warm, the heater core can have an air pocket in it as well.

Damn, I missed that bit! :dunce:

Addendum: The first thing you should do is put the heater in the HOT position. You'll need to turn the ignition on first to operate the stepper motor. Leave the heater on until after your test drive is complete :)

I vote for archiving!

And here's my 2 cents, based on what I just learned on my car this weekend. If you're just letting it idle while filling it, after the t'stat opens, brings the revs up to about 2K and keep it there for about 30 seconds or so. Mine was idling for 20 minutes and not the tiniest bit of heat was coming out of the vents, with the heat controls up full, even though the t'sat was open. Brought up the revs, and within a minute, the heat was full hot. I'm guessing the extra circulation caused by increased water pump revs gets the coolant into all of the little hiding places in the system, forcing out the air.

archive this

I'll archive the topic when it's finished.

Follow the steps above, Heat on, T'stat open, fill the res, yadda yadda yadda. Then add the following...........

this is dangerous but it works for me. I wait until the motor is good and hot. I then crack open the bleeder valve slowly opening it further and further until I see steam coming out. Then as the air bubbles come out it turns from steam to coolant bubbles and then just coolant drips. Close the bleeder and rock on. This should get the last of it. My motor had a coolant leak somewhere so I had to do this final step about once every two weeks. The last step I described was the only thing that shut the buzzer up (*^&* Buzzer!!!)

Anyone have any good info on why S5s don't have a bleeder valve and how Mazda was expecting us to bleed off air?

I'd love to do that hot bleeding step to "finish off" the system... but I guess I can't.

Does the S5 automatically remove the air via the overflow? =/

--Gary

What do you do in this situation? My heater blows cold/lukewarm in my GXL due (Hopefully) to an air bubble. What is a good way to bleed it out?

Tofuball - Did you recently have the cooling system open, or has your heater always been lukewarm? If it's always been that way, it may be partially blocked due to corosion build-up.

The system was open: The engine was out of the car! :D

Normal Bob,

I have seen two pictures of the bleeder valve. One is a plastic wing nut, one is a large threaded plug with a slot in it for a flat head screw driver. It should be located on the highest part of your upper radiator line. It will be on the left handed side if your standing in front of the car looking in(actually the right handed). If it is not there then the real motor heads will have to advise you

Thats interesting.

I'll go look real quick but I'm almost sure there's a threaded hole on the thermostat neck that I have no idea what it is for (assuming it's for mounting the wires I have zip-tied out of the way right now lol) but let me go check if it looks like there's more to it than just a threaded hole...

If it's not that, I don't have one.

--Gary