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Old 08-24-2010, 05:48 PM   #1
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Default Weird problem with radiator?

So whenever I fill up the radiator (About an inch from the top is what I've been told to do) it pisses water out of the overfill hose. When it's finally cooled down, the water level is below the top of the grate, if you know what I mean by that. It doesn't do it unless I've filled it up.

Note that it either does it when I've turned the car off OR if I've slowed down and am about to turn the car off. Yesterday it pissed all over my friend's driveway, which is when I discovered it was leaking from there.

Am I correct in filling it up until about an inch to the top? Should I get a higher pressure cap? I'm just running the stock one right now, I don't know if it's ever been replaced.

Also note: I'm running strait water and my temp hoovers around 190/200 depending on the outstanding weather.
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Old 08-24-2010, 07:25 PM   #2
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Your radiator will never push out water when heating up, and then follow it with sucking in air while cooling down under normal circumstances. It will push out water while warming up, and then suck that water back in while cooling. You've got fluid in your overfill tank to start with, right? Check to see that your overfill tank cap has the hoses routed right. It sounds to me like you've got them backwards at the overfill tank. The hose coming from the radiator should have the 'straw' going to the bottom of the overfill tank. The hose going to atmosphere shouldnt.

If you've got the straw on the atmosphere hose instead of the radiator hose, then your car will pee coolant when warming up, and then suck in air when cooling down.

Realistically, you'll want to fill your radiator completely to the top while cool, and then ensure that you burp the cooling system.
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Old 08-25-2010, 10:50 AM   #3
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Another quick thing to swap out, would be the rad cap.... Could be that it's not holding pressure in, or not letting pressure/air out properly....

Dave,
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Old 08-25-2010, 04:41 PM   #4
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I haven no overfill tank since I just run strait water. The hose just pisses on the ground, which is why I know it's coming from there and exactly when it happens.
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Old 08-25-2010, 04:55 PM   #5
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Quote:
Originally Posted by rider384 View Post
I haven no overfill tank since I just run strait water. The hose just pisses on the ground, which is why I know it's coming from there and exactly when it happens.


Are you ******* trolling? This is probably some of the stupidest **** I've ever heard. I covered this **** in 6th grade physics class.

The overflow tank is not there to keep toxic antifreeze from falling on the ground, it's there to keep fluid in your radiator, dumbass

When fluid heats up, it expands. When it expands, it has to go somewhere. The radiator cap is not there to keep water in the radiator, that isnt possible. Liquids are uncompressable - that is to say, it's entirely impossible to take one liter of water, apply 100 Bar of pressure, and expect it to physically occupy less than 1 liter of space. A barometer submerged in the fluid, will however show the pressure increase, and the walls of the container will experience the pressure increase as well. When your coolant heats up, of course the pressure goes up, but it also needs a way to escape. As far as the liquid is concerned, we could just have an overfill tank with an unpressurized radiator cap, and the liquid would be happy all day long exiting the warming radiator, and then reentering the cooling radiator.

The pressurized radiator cap is simply there to keep the coolant from boiling - nothing more.

So, to recap:
Water heats up, radiator pressurizes as water expands. The hot water must physically occupy more space though, so it goes out the overflow tube to the OVERFLOW TANK. The entire cooling system maintains pressure equivalent to what your radiator cap allows for, this prevents boiling coolant.

When the water cools, it contracts. Since the same mass of colder water must occupy LESS space, your radiator quickly falls below atmospheric pressure, and water is drawn back into the radiator from the OVERFILL TANK through the radiator cap.

Solution to your problem: Reinstall a damned overflow tank.
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Old 08-25-2010, 05:09 PM   #6
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Quote:
Originally Posted by rider384 View Post
I haven no overfill tank since I just run strait water. The hose just pisses on the ground, which is why I know it's coming from there and exactly when it happens.
omg

:buffon:




Just a heads up, you are going to want to keep a small percentage of antifreeze or water wetter in your cooling system also. Water is not a lubricant and will corrode. But for pete's sake put the overflow tank back in, that's why they make them.
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Old 08-25-2010, 05:14 PM   #7
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:buffon:
AH HA!!! FANTASTIC!!!

Rider, I hereby pass on the Mini-Sig award to you. Please copy it from my sig to your sig and I can get rid of mine. Please keep it in your sig until you redeem yourself and pass it on to the next person.
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Old 08-25-2010, 05:34 PM   #8
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^ Doooo eeeet
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Old 08-25-2010, 05:57 PM   #9
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I guess I know nothing

Also figures that it was CR that told me I could remove it
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Old 08-25-2010, 06:17 PM   #10
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you can remove the factory one for cleanliness, but you still need one of some kind, whether it's fancy aluminum or a beer bottle
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