Not if I understand post 82 correctly.The overflow tank is vented. It is atmospheric pressure, acting through the vent, that 'pushes' the coolant back into the rad.
Not if I understand post 82 correctly.The overflow tank is vented. It is atmospheric pressure, acting through the vent, that 'pushes' the coolant back into the rad.
The overflow tank is vented. It is atmospheric pressure, acting through the vent, that 'pushes' the coolant back into the rad.
Fascinating . . .
Interesting, probably why the 16 psi radiator caps are used.
This allows the cooling system to build pressure to 16 psi to overcome the (push back) atmospheric pressure of 14.7 psi in the vented reservoir tank.
When the coolant is expanding, then it is allowed to flow into the reservoir from the pressure difference between the 2.
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But it vents into a closed vessel that only vents at 16 so the system only vents at 16lbsThe radiator vents at 7PSI.
I get it, trust me. We're on the same page. But like it or not, in that scenario, the radiator is still vented.But it vents into a closed vessel that only vents at 16 so the system only vents at 16lbs
Think of a water heater over pressure valve
If you cap the open end of the drain line it no longer is an overpressure vent it is a plug.
Another analogy...
If you put a hose on the nipple under the radiator cap and plug the open end of it. That hose will not allow pressure out of the radiator to atmosphere, so it does not matter what the cap pressure is it is plugged and the pressure in the rad will just increase tillt something let's go.
Explain please.I get it, trust me. We're on the same page. But like it or not, in that scenario, the radiator is still vented.
His example was a radiator with a 7LB cap with an overflow tank with a 16LB cap. The radiator will vent TO the overflow since it has a lower pressure rated cap than the overflow tank. While the overflow tank may not be vented, the radiator IS vented to the overflow tank.Explain please.
It will only vent an insignificant amount so for the practical purposes needed for a properly working cooling system it is not vented. Once the pressure is equalized at 7psi between the tank and radiator it will increase in pressure until it reaches the pressure of the cap on the reservoir. Then it will vent like a properly working cooling system is designed to vent.His example was a radiator with a 7LB cap with an overflow tank with a 16LB cap. The radiator will vent TO the overflow since it has a lower pressure rated cap than the overflow tank. While the overflow tank may not be vented, the radiator IS vented to the overflow tank.
I'll vent the difference between the 7PSI cap and the 16PSI cap. I guess that's insignificant? Regardless, the radiator is still vented TO the overflow. It's a silly argument, since the example is just that. An example that doesn't exist. Maybe a better word we can agree on is "expansion" rather than venting?It will only vent an insignificant amount so for the practical purposes needed for a properly working cooling system it is not vented. Once the pressure is equalized at 7psi between the tank and radiator it will increase in pressure until it reaches the pressure of the cap on the reservoir. Then it will vent like a properly working cooling system is designed to vent.
If the expansion tank was the size of a 5 gallon bucket I might give it to you.I'll vent the difference between the 7PSI cap and the 16PSI cap. I guess that's insignificant? Regardless, the radiator is still vented TO the overflow. It's a silly argument, since the example is just that. An example that doesn't exist. Maybe a better word we can agree on is "expansion" rather than venting?
Ok, then what about the Fords of the 60s? They had expansion tanks above the radiator that were on the order of about a half gallon.If the expansion tank was the size of a 5 gallon bucket I might give it to you.
That tank was effectively the top of the radiator and had the pressure cap on itOk, then what about the Fords of the 60s? They had expansion tanks above the radiator that were on the order of about a half gallon
Kitty's 04 Escape is like that. My 04 Powerstroke truck was like that. The overflow tanks in those instances are essentially like the early Fords and actually a part of the radiator.That tank was effectively the top of the radiator and had the pressure cap on it
(IIRC)
Thunderbirds IIRC.
My 56 Ford pickup did not have that, my 63 econoline, 65 and 68 mustang either.
The newer cars have a closed system in that the expansion tank has the pressure valve on it. And an air gap to allow for the expansion. As the pressure gets to cap pressure the fluid is well below the cap and only air is expeled or sucked back in.
JUST LIKE MY 67 WITH NO OVERFLOW.
the air gap in the top tank of the radiator tank is sufficient volume to hold the expanding fluid. As the pressure goes up it reaches cap pressure and expels air.
As the coolant cools off the and it's volume reduces it sucks (atmosphere pressure really pushes) air back into the top tank.
Not a drop of fluid is spilled, no overflow is needed.
Bottom line. If the radiator is filled 100% full the expanding fluid has to go somewhere. When the pressure in the rad gets to cap pressure fluid will exit the radiator. If it goes into a closed vessel ( no vent) it will pressurize the vessel in short order and continue to build pressure till something let's loose.
It's not rocket science. But some symantics complicates things.
In one of the OP's posts he stated that his friend confirmed that his "overflow" did not have a vent, and that he was going to reroute his line from the rad to the bottom of the "overflow" and drill a hole in the cap for a vent.
My 2007 Ford Taurus is that way tooKitty's 04 Escape is like that. My 04 Powerstroke truck was like that. The overflow tanks in those instances are essentially like the early Fords and actually a part of the radiator
There is a electronic heating device that looks to work well.. I've tried removing the block drain plugs but they're stuck pretty
More details please.There is a electronic heating device that looks to work well.
Are you using an overflow bottle?There is still an overflow issue I believe, as the engine does heat up if I sit still too long. I can't remember how high it gets, if it reached 200 or not, and it's hard to test now that winter is here
I might have mentioned before. If it isn't puking coolant out it isn't overheating. 200 would br perfect for a 195 thermostat.Just an update in case anyone was curious. A few months back I had discount tire flush the whole system out since after several weeks my usual shop didn't seem too concerned with returning my calls. I haven't overheated since. There is still an overflow issue I believe, as the engine does heat up if I sit still too long. I can't remember how high it gets, if it reached 200 or not, and it's hard to test now that winter is here.