AST Delete Kits
Yes I know. So when you plug the hole in the radiator how is the oem air bleed system going to function? Like I said before I don't exactly know how it works but looks to me like when you're changing the filler neck to 88 oem filler neck and when you plug the extra hole on the radiator you're eliminating the air bleed system aka AST. Maybe I'm wrong 
The Man
Joined: Aug 2001
Posts: 702
Likes: 0
From: Lee's Summit Mo.
The air is being bled at the cap, the overflow is pushed out into the overflow container, the stock system lets some recirculate back into the radiator or go to the overflow. Now you make it overflow to the overflow tank. The best way to ensure there is little or no air in the system is to top off the filler neck with the rear throttle body line undone and venting. That way you fill the rear housing entirely to the top without trapping that air in the block. After water starts coming out of the rear hose. Connect it to the throttle body and voila!
Cavitation is a localized very low pressure zone in the coolant, from shear or other forces applied to the liquid (e.g. poorly shaped water pump impeller blades). The cavitation zones immediately implode and disappear. It is this implosion that can over time abrade the surrounding metal. The zones definitely do not stay and circulate around to the AST.
Boiling coolant creates bubbles of vaporized coolant. Not air. They disappear when the coolant is cooled. If the boiling is localized (say, to the spark plug area) then the boiling coolant will not circulate around to the AST. And if the whole system is so hot that it is boiling coolant everywhere, you have bigger problems than the AST can solve.
It seems likely to me the AST is there to remove dissolved air that was trapped elsewhere in the system, or is being forced out of solution because of temperature changes (hot liquids can hold more dissolved gas than cold liquids). The engineers also need to design the car so that it can go 100K miles straight from the factory without anyone opening the radiator cap.
I open the radiator cap all the time, and top up the coolant regularly. I thus rely on the cap chimney to capture bubbles, and deleted my AST. When changing coolant, it does take several hot/cold cycles to remove all the air.
Thread Starter
Full Member
Joined: Oct 2012
Posts: 96
Likes: 0
From: Nashville
Neither of these creates "air" in the coolant.
Cavitation is a localized very low pressure zone in the coolant, from shear or other forces applied to the liquid (e.g. poorly shaped water pump impeller blades). The cavitation zones immediately implode and disappear. It is this implosion that can over time abrade the surrounding metal. The zones definitely do not stay and circulate around to the AST.
Boiling coolant creates bubbles of vaporized coolant. Not air. They disappear when the coolant is cooled. If the boiling is localized (say, to the spark plug area) then the boiling coolant will not circulate around to the AST. And if the whole system is so hot that it is boiling coolant everywhere, you have bigger problems than the AST can solve.
It seems likely to me the AST is there to remove dissolved air that was trapped elsewhere in the system, or is being forced out of solution because of temperature changes (hot liquids can hold more dissolved gas than cold liquids). The engineers also need to design the car so that it can go 100K miles straight from the factory without anyone opening the radiator cap.
I open the radiator cap all the time, and top up the coolant regularly. I thus rely on the cap chimney to capture bubbles, and deleted my AST. When changing coolant, it does take several hot/cold cycles to remove all the air.
Cavitation is a localized very low pressure zone in the coolant, from shear or other forces applied to the liquid (e.g. poorly shaped water pump impeller blades). The cavitation zones immediately implode and disappear. It is this implosion that can over time abrade the surrounding metal. The zones definitely do not stay and circulate around to the AST.
Boiling coolant creates bubbles of vaporized coolant. Not air. They disappear when the coolant is cooled. If the boiling is localized (say, to the spark plug area) then the boiling coolant will not circulate around to the AST. And if the whole system is so hot that it is boiling coolant everywhere, you have bigger problems than the AST can solve.
It seems likely to me the AST is there to remove dissolved air that was trapped elsewhere in the system, or is being forced out of solution because of temperature changes (hot liquids can hold more dissolved gas than cold liquids). The engineers also need to design the car so that it can go 100K miles straight from the factory without anyone opening the radiator cap.
I open the radiator cap all the time, and top up the coolant regularly. I thus rely on the cap chimney to capture bubbles, and deleted my AST. When changing coolant, it does take several hot/cold cycles to remove all the air.
Intelligent information.
Extra insight like this is why I got rid of my AST too.
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