vt how to bleed the air from the cooling system ?

[delcowizzid]

i just fill the system when cold fit cap start engine let warm up and pressurize then undo bleeder all air pisses out when water only comes out shut bleeder done repeat next cold start to get any remaining air out can take a few goes no matter how you fill the system as air gets trapped in the heads pretty easy and doesnt come out untill engine running/driving

 

[RiCeY]

It has got me stuffed why so many people have trouble with air locks and bleeding the air out of the ecotec engine.I have drained my vs radiator that many times that Ive lost count,and Ive never had trouble,just fill it up again and go.I mentioned about this to a radiator repair bloke one day,and he said that because the bleeder screw is there for holden to connect their bleeder tool to,people think they have to undo it to bleed the air from the cooling system.He said they didnt worry about touching it,they just fill the radiator and thats it.I always used to undo the bleeder a little bit whilst filling the radiator and then just tighten it up again.But then after talking to this guy,I didnt bother with it and I have still never had one problem with having to bleed it because of air locks or whatever.Id just try filling the radiator to the top and also make sure the overflow bottle is at the max level and then recheck the overflow bottle and radiator levels after its been driven or bought up to operating temp and completely cooled down again.This is all I do and it works every time.

The radiator repairer you spoke to is an idiot. The bleed point is there for a reason and should be used when bleeding the system.

Run the engine with the bleeder open until coolant comes out in a steady flow and close it, then fill the radiator and put the cap on a go for a spirited drive. Carefully open the bleeder again and if no air comes out youre done. Once the engine has cooled remove the radiator cap and top up if neccessary.

 

[IMCRZY]

i just fill the system when cold fit cap start engine let warm up and pressurize then undo bleeder all air pisses out when water only comes out shut bleeder done repeat next cold start to get any remaining air out can take a few goes no matter how you fill the system as air gets trapped in the heads pretty easy and doesnt come out untill engine running/driving

& what if the air lock in the top of the engine causes a hot spot n stuffs somethin in the mean time???

The way that it has been explained in this thread is the best & correct way of doing it(AND THE EASIEST), i dont see why it is so hard for people to just leave it at that....

 

[VYMAD]

OK, the idea of using a bottle is to make the level of the coolant higher than the bleed valve. I use some sort of medium sized orange juice bottle with duct tape wrapped around the neck. I just pull the overflow pipe off at the radiator filler neck, then it's easy to block the hole with one finger rather than trying to hold the entire overflow tube up in the air. Start the procedure while the engine is cool and no pressure in the system, for obvious reasons. But you need to idle the engine until normal operating temp is reached and the thermostat has opened, as the bleed valve is above the thermostat. No point doing it with a cold system. Then let the air out of the bleed valve with plenty of coolant in the orange juice (or whatever bottle.)

 

[Jacko84]

The radiator guy you spoke to is an idiot, you need to bleed the system holden dont just put things there for no reason, air pockets need to be bleed out

 

[Benboy]

The best way is to have the front of the vehicle on ramps or jacked up so that the radiator filler is generally higher than the rest of the engine. Let gravity do the work. No special tools or equipment required.

 

[Brett_jjj]

Listen to these guys on here calling this guy an idiot.He does radiators on fleets of heavy vehicles etc,and theres always shiploads of cars there..Its not a small buisness,so Id listen to him before someone on here who may or may not know anything about it,or just knows what they have read somewhere.And if it were true that you HAVE to undo the bleeder screw,then why havent I had problems with all the commodore cooling systems I have done over the last few years ,which would be around 20 or so,probably more.None of these had any problems with hotspots or air pockets or whatever after being filled.I think you are doing something wrong if you have problems with it.

 

[VYMAD]

Listen to these guys on here calling this guy an idiot.He does radiators on fleets of heavy vehicles etc,and theres always shiploads of cars there..Its not a small buisness,so Id listen to him before someone on here who may or may not know anything about it,or just knows what they have read.And if it were true that you HAVE to undo the bleeder screw,then why havent I had problems with all the commodore cooling stsyems I have done over the last few years ,which would be around 20 or so.None of these had any problems with hotspots or air pockets or whatever after being filled.I think you are doing something wrong if you have problems with it.

Bullshit. The system needs to be bled. Why, pray tell, do they have a bleed screw then?

 

[Brett_jjj]

Who knows why, why doesnt it cause trouble if its not used?Thats what Id like to know.

 

[VYMAD]

Who knows why,and why doesnt it cause trouble if its not used?

As stated earlier, air pockets can create hotspots, for the little effort involved to bleed the system, I certainly do it. But hey it's your car, do what you want.
To the OP, my post number 14 is the correct way of bleeding the system. If your keen, you can repeat the simple process after a couple of days' driving to ensure the air is all out, as sometimes a bit of air can still work it's way to the top.