How to bleed air out of cooling system on a Pontiac Montana, GM 3.4L 

+Gary Arbaugh no problem. I did brave the snow. It is chilly when a bubble would hit the heater core and you had no heat. Lol This was made years ago due to the crappy video quality i apologize.

Great tips for sure. That would have to be some extra cold water to cause cracking though. It would mix in enough with the other hot coolant and be not much of a shock in my opinion. All great tips. Thanks!

Yes that is true. Glad we came to a conclusion😃. My heater core was actually plugged in mine when i got it. I had to pressurize it each way with a garden hose and it eventually unplugged it. Thankfully i never had to pull it as i hear that is a bear of a job. I had good success on bleeding when i parked uphill with that rad cap off. Seemed to really help when i had it parked. Anyways glad we are off on the right step. Let me know if you get all that air out. I know they say to make sure your rear heat is on also.

Actually never though of the rear heat, I bet that is where most of the air was. I think I got all the air out because, I checked the rariator and It was full. As far as doing the heater core it is very easy. I used a service manual and it made it way easier. The hard part was getting the air out afterwards because, I ignored the directions on the service manual. If you do one you have to plug the heater hoses or you will get a ton of air in the system. You have to open the bleeders while filling the radiator and then let it warm up and then after it cools of check it and fill it. Then you have to keep checking the level for at least a couple of days after getting it up to operating temp and then letting it cool off. Also never leave the cap open while it is running, a great way to make it overheat is leaving the cap off.

So you should have the heat on while you’re bleeding the air? My van is overheating. It’s not leaking.

@crankbaitinchad1729 correct heat should be on.

No the highest would be best last but it really will not matter.

Could be. If the water pump has an air pocket it won’t circulate proper.

Hey Jake, no you don’t have to.

Most likely you would be fine with the one. Just drive and you may have some temp spikes that will work themselves out.

Check inside the trunk. That is where mines was

mine is doing the same, im replacing the thermostat today have you done that yet?

@@jrayburn6169 a while back...couldnt hurt to do it again.

@@bananapie2198 Just got done replacing mine today was about a 3 hour job and pain in the ass but it worked thankfully, I’d give it another try

@@jrayburn6169 sweet thank you for reporting back!

@@bananapie2198 no problem best of luck to you

It will most likely be different then.

Schneids15 Ohhhh ok

Could be? This is what i did and it worked great and really got a lot of air out 🤷🏼‍♂️

Schneids15 Will this work if I only have just the overflow tank? I believe I have a closed system I don’t have a radiator cap

Can’t see why not. If air is coming out it is working.

Schneids15 Yes, closed system. If no radiator cap. Overflow would be the best bet, I bleed air from the one by water as well and got the air out. Now I’m trying to figure why my fans kick on only when ac is turned on 🧐🤷🏾‍♂️

Get rid of it scrap it i went through radiator fans new bleed valves new hoses new fans flushed system when everything replaced still broken down get rid of that piece of shit 2000 later at least worth 200 buck's scrap thats it

Head gasket, intake gasket replaced?

+hugh3rdof5 always worked well for me. I would bleed and drive then bleed again if i had a temp spike. Almost 95% of time air at the water pump end bleeder. Worked great. I flushed everything twice in that van when i had it and never had an issue this way. I am aware of the extended system but that was always lower when i flushed and never had issues with that. Thanks for the tips.

Are you saying flushing the cooling system will get all the air out? The dealer claims flushing will get all the air out and I'm not sure I believe them.

Hi. Can you tell me how did you figure out with that, please?

Did you ever make any progress on yours? I had to flush mine because the Dextron turned to clay in the entire engine. But now I can't get the dang thing to bleed no matter what I do. Any fluid in the system just turns to steam. I tried backfilling the motor and pumping it with a hose. Ugh.

@@bananapie2198 how did that work for you? My wife and I are getting ready to coolant flush our 03 venture same engine. Changing the sparks was a nightmare lol

Either or. It will get warm running but will not matter. hope this helps!