Do the pressurized "overflow" tanks on the newer model vehicles re-circulate the coolant? For example, when the vehicle reaches operating temp, does the coolant go from the rad to the overflow tank via the rubber hose connecting the rad and overflow and then back to the engine? Just wondering, because if one wanted to freshen up the coolant occasionally, would it make sense to siphon some out of the overflow tank now and then ?
Pressurized "overflow" tanks
- Thread starter rocketman
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It does
It's does circulate some. Some I think have a line to the lower radiator hose so they probably circulate more when the thermostat opens but they still acts more like a reservoir than a radiator does under the cap, drawing fluid in and releasing. so I think it's good to drain out sometimes.
Oh yeah I'm not sure if that's what you meant but never run the reservoir low.
Oh yeah I'm not sure if that's what you meant but never run the reservoir low.
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Yes, the amount of recirulation depends on the system. My '88 Jeep Cherokee has the pressurized overflow tank (known as a closed system in the Jeep world) that definitely recirculates the antifreeze - the water pump bypass comes through the tank. I'll note that this system is terribly finicky on the Jeep, which is why many owners convert to the open system found on '91 and up Cherokees. That being said, the pressurized overflow system on my F150s has never given me a hint of trouble with 350,000 miles logged on two trucks. The Jeep is another story...
My saturn doesn't much. The tank drains into a "tee" in the bypass pipe/hose. The factory recommends a touch of stop leak
and I had to drain the rad a bit to get the dust to fall down into the circulating system... so it wouldn't just clog up the surge tank.
I know for refers to their system as a DEGAS system.
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