Changing coolant in a 2004 Tahoe z71 with rear heat

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Red Rider

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You drain system, Put on the fitting, pull vaccum. All hoses will collapse and you can test for leaks. Dumped coolant into bucket and added water. Then you open a valve and it sucks new coolant in. Very fast, as long as it does not take you 30 min to take the lower hose off :)

First time I used it. Very happy. Only issue i had was that it did not drop back down to zero. I tried adding suction but it did not really work. Next time i take it out, I will let it get warm and watch levels and temp and add some fluid if necessary. The overflow tank is a little higher than normal but I assume it will get sucked in.
 
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Interesting. I've never heard of this process. Does it just hook to an AC style vacuum pump?
 

MassHoe04

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You drain system, Put on the fitting, pull vaccum. All hoses will collapse and you can test for leaks. Dumped coolant into bucket and added water. Then you open a valve and it sucks new coolant in. Very fast, as long as it does not take you 30 min to take the lower hose off :)

First time I used it. Very happy. Only issue i had was that it did not drop back down to zero. I tried adding suction but it did not really work. Next time i take it out, I will let it get warm and watch levels and temp and add some fluid if necessary. The overflow tank is a little higher than normal but I assume it will get sucked in.
Pretty cool! I am sure it has potential to make life easier. Still a little spendy for my tool box, at this point.
If I have to drain/refill coolant, I'll just have to do the best I can the old-fashioned way.

So many other tools I really need to build my arsenal... But still cool tool! Thanks for passing that along to us.
 

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Interesting. I've never heard of this process. Does it just hook to an AC style vacuum pump?

Probably connects to a compressor, like some of the commercial brake bleeder systems do. Based on the pressure, the system produces vacuum.
 
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Correct. Hooks up to your compressor to make vacuum by creating a venturi effect. The device connects to the expansion tank (or radiator if you have older vehicle) and a screw expands the rubber gasket to make the seal. You would need a compressor.
 

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What is the AirLift system?
God's gift to this world when working on cooling systems

It's a 2 part system that will pull somewhere around a 90% vacuum on a cooling loop depending on your air supply pressure. (Units on the gauge are rated in inHg, with 30 being full vacuum, I'll get around 26-27). From there, you can either seal the system and observe pressure - leak testing. Though of note, because it's under vacuum, it's not perfect. It's possible to get a goofy seal that seals under vacuum but leaks under pressure.

But what it'll also let you do, is fill the system with coolant, using the ΔP to draw in coolant. End result is something that's +/- perfectly bled without turning the engine over.

Depending on the vehicle, it can save quite a lot of time trying to purge air from the system. These rigs aren't too bad, just need to watch air-locking the water pump on fill. But others? Like some specific VWs, fords, or porsche, you can easily be there fussing for 30-45 minutes dealing with 3-4 little bleed screws on the thing and air locks and just being generally lame. Also great for vehicles that use an electric water pump (looking at you BMW) that would normally need a rather $$$$ scanner to run a bleed procedure.


It's generally not a tool you'd need for a home-gamer gig. Cost/reward, and you definitely won't power it with your standard pancake compressor. But boy howdy is it a great one when you start dealing with tricky stuff.
 
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Yeah, What he said :)

I had a VW once that I drained the fluid and had a hell of a time getting rid of the air. Figured this was the way to go. When you consider the cost of doing it at a garage, it paid for itself already. Plus you can use it to test radiators (off vehicle) etc.
 

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Correct. Hooks up to your compressor to make vacuum by creating a venturi effect. The device connects to the expansion tank (or radiator if you have older vehicle) and a screw expands the rubber gasket to make the seal. You would need a compressor.
I saw the vacuum pump on the Amazon ad, so I figured you'd have to be in it for another $100+ just for a vacuum pump to go with that kit. Running on regular air compressor and not having to buy a vacuum pump makes this a much more affordable option to consider... Thanks for the info.!
 
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