Pressurized Overflow Jug
Pressurized Overflow Jug Hello,
I'm installing a 2004 5.3 LY7 / 4l60e into a 1978 Caprice. I have purchased a Griffin radiator for the project (part# CU-00008-LS). This radiator has a radiator cap on it. Can I use my stock overlfow jug from the 78 caprice which has a vented, non pressurized cap?
Thanks,
Brandon
I'm installing a 2004 5.3 LY7 / 4l60e into a 1978 Caprice. I have purchased a Griffin radiator for the project (part# CU-00008-LS). This radiator has a radiator cap on it. Can I use my stock overlfow jug from the 78 caprice which has a vented, non pressurized cap?
Thanks,
Brandon
Thanks for the reply. I'm surprised I've never thought about this before, but how does a pressurized system maintain the PSI if the overflow jug is vented to atmosphere, even on old systems?
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From: Central Cal.
Newer systems put the overflow within the pressure system, which necessitates the pressure cap on the overflow jug.
Thanks for the reply. So the weight of the coolant in the non-pressurized jug effectively seals the system and the PSI of the system cannot overcome that weight to push it back up into the overflow jug until the pressure reaches above the normal PSI of the system. That makes sense to me, but then if that does work wouldn't that function as an effective pressure relief and the pressure cap wouldn't be needed?
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From: Central Cal.
The pressure cap builds up to around 12psi in the system. When that pressure is exceeded the overflow "burps" into the overflow tube which has its other end connected to the bottom of the overflow tank, thereby sealing it. The overflow tube does not "see" system pressure, only overflow volume at atmospheric pressure. When the system cools, a vacuum is made in the radiator which then sucks some coolant back into the system until even pressure is met.
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From: PDX-OR-USA
To help keep it clear,, with cap on radiator and a vented tank its a "recovery system".
With the cap on the tank and tank pressurized, and no cap on the radiator its an "expansion system".
The tank on the expansion system should almost never be filled to the top, it will over-pressure the system.
With the cap on the tank and tank pressurized, and no cap on the radiator its an "expansion system".
The tank on the expansion system should almost never be filled to the top, it will over-pressure the system.
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From: PNW
See how your radiator cap has “psi” or “bar” stamped on it preceded by a number? Thats what it does, it maintains your systems pressure. The overflow tank is called an overflow tank because that’s all it is - an over flow tank. If it was a pressurized part of the system it would be called an expansion tank.