Does the coolant in the reservoir ever circulate through the cooling system? Not a surge tank setup, but a radiator with cap and overflow hose that goes into a separate reservoir. Similar to this picture.
Does coolant in reservoir ever cycle through the system?
- Thread starter Johnny248
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yes
Every time the coolant temp rises, some fluid gets pushed into the overflow tank and any time the engine cools down, a similar amount gets sucked back in.
Every time the coolant temp rises, some fluid gets pushed into the overflow tank and any time the engine cools down, a similar amount gets sucked back in.
^This.
Yup
Expansion/Contraction with temperature changes...
Expansion/Contraction with temperature changes...
Some vehicles went to the circulation system before others. You can check the cap on the coolant tank. It will be a sealed cap capable of taking pressure. There will also be an inlet and an outlet. Coolant circulates through it. It’s more than just taking the expansion fluid. Here is one from Rock Auto for a 2005 Ford Taurus. The inlet and outlet are circled.
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Not in OP's example.
What's the backstory, does OP want to do a "gentle" coolant changeout? Fix a concentration issue to get back to 50/50? Working only with the overflow bottle is a dumb way to maybe eventually get there.
In my VW tanks, the coolant flows through. The tanks get too hot to touch after a drive and the only way they could do that is if coolant circulates.
I take advantage of this by sucking out the coolant in the tank when it is cold and replacing it with new coolant about six times a year.There is NO dirt in my tank and my coolant always looks fresh and clean. I never drain and fill the systems.
I take advantage of this by sucking out the coolant in the tank when it is cold and replacing it with new coolant about six times a year.There is NO dirt in my tank and my coolant always looks fresh and clean. I never drain and fill the systems.
Maybe he just wants to add distilled water to replenish (that which has evaporated) and would like the juice in the the bottle to have anti-freeze properties by the time Winter blows in.
Yes, it does. A coolant change relies on this. After you refill the radiator with coolant and then let the vehicle run to purge air as you keep topping the coolant, eventually the process will seem to stop. Then you install the radiator cap and use the vehicle. Over the next several days the system will much more slowly purge the remaining air and will suck the coolant out of the reservoir to replace the air. You should keep an eye on the coolant level in the reservoir and top it as necessary until that process stops, which could be a week or so. Just went through this a few months ago on my pickup.
What Year Model car and engine?
I was curious after reading a bottle of Hy-per Cool Super Coolant. I have witnessed after doing cooling system work, that the system will pull some coolant from the reservoir after running if it was completely full. I know that it will bypass the gap it pressures get to high. I just didn't know if it was a normal part of the colony system or only when it's too high, too low. This bottle says "Can be added to overflow tank, but will take 4 to 5 heating and cooling cycles for product to fully enter system"
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"It depends."
If you are referring to an overflow tank, no. That is supposed to be a one way path, since the radiator cap only allows coolant to escape when the pressure exceeds the caps rating. If the cap has failed, then you will see some back and forth, but mostly overflowing.
If referring to an expansion tank, yes. It's part of the circulation.
If you are referring to an overflow tank, no. That is supposed to be a one way path, since the radiator cap only allows coolant to escape when the pressure exceeds the caps rating. If the cap has failed, then you will see some back and forth, but mostly overflowing.
If referring to an expansion tank, yes. It's part of the circulation.
My three Chrysler vehicles all have a standard overflow. The two GM's use a surge tank with the cap on it.
I that was true on modern vehicles, you would not observe the reservoir level change from hot shutdown FULL - to cold start LOW
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Yes.
What I learned on our GM is that it is the function of the radiator cap to allow coolant to go back and forth from the reservoir.
One day, I noticed coolant above max hot.
Coolant above max, cold. I was baffled.
Then, I saw the upper rad hose was collapsed cold.
Got a new cap, and back to normal. Max line cold, above max hot. Radiator hose not collapsed cold.
What I learned on our GM is that it is the function of the radiator cap to allow coolant to go back and forth from the reservoir.
One day, I noticed coolant above max hot.
Coolant above max, cold. I was baffled.
Then, I saw the upper rad hose was collapsed cold.
Got a new cap, and back to normal. Max line cold, above max hot. Radiator hose not collapsed cold.
Another variation is a radiator with no radiator cap at all. The tank cap serves instead. 2008 Chevy Suburban 3/4 ton.
for a system with 3 gallon capacity it will exchange almost 6 ounces to expansion tank and then 6 ounces back from 50F to boiling, then back again. Guessing your overflow would be cycled out pretty much within a week of driving.
^^ this
No, not that. The cap is a two-way device. After the heated coolant expands into the overflow, it re-enters the radiator upon cooling. It’s also a return valve.
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It depends. Some cars utilize a one way. Others have a two way.
