Leaking coolant - Chevelle Tech
Heating & Cooling Heating, cooling and air conditioning

  • 4 Post By marcrose
  • 1 Post By HKalin
  • 2 Post By blm
  • 2 Post By Kirk's67SS
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post #1 of 8 (permalink) Old Mar 27th, 20, 7:12 AM Thread Starter
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Leaking coolant

Everytime I take my car out, the next morning I see coolant in garage floor. It doesn’t leak while driving or idling that I see, only when off and sitting? I think it’s coming from overflow hose on radiator. Should I be concerned? Just add a overflow bottle? Wasn’t sure if something major would make this leak. Thanks.
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post #2 of 8 (permalink) Old Mar 27th, 20, 9:16 AM
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Re: Leaking coolant

My 70 ss 454 doesnt have an overflow bottle from factory.You have to leave the radiator an expansion zone or it will overflow everytime.(3-4 inches low)
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post #3 of 8 (permalink) Old Mar 27th, 20, 10:13 AM
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Re: Leaking coolant

Take and tighten up all your hose clamps it could be seeping out there.
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post #4 of 8 (permalink) Old Mar 27th, 20, 2:16 PM
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Re: Leaking coolant

So have you been adding to the radiator after each time it overflows? If so it will keep overflowing. A few inches below the neck is the max fill level.
If you have not been adding coolant/water then its leaking or possibly a bad cap.
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post #5 of 8 (permalink) Old Mar 27th, 20, 2:44 PM
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Re: Leaking coolant

Hard to tell as we do not know if it is a Chevelle Question and what year !

When you turn off/sut down the Engine after a drive it will heat up more until it starts to cool down
so when it heats more than when the car was running the Coolant is likely expaining and pushing out at the Rad Cap
see Post # 4 and 3

Adding a Overflow Bottle to the Overflow Tube means no more Coolant on the Garage Floor
but that does not address why it is flowing out, see Post # 4
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post #6 of 8 (permalink) Old Mar 27th, 20, 2:53 PM
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Re: Leaking coolant

Put a closed system recovery tank and radiator cap. Welcome to modern technology and innovation.
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post #7 of 8 (permalink) Old Mar 27th, 20, 6:34 PM Thread Starter
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It’s a 70 Chevelle 350. My fault, I fill the radiator too high. It’s definitely coming from overflow hose. Thank you everyone for straightening my dumbass out. Now onto fixing the leaky power steering gearbox.
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post #8 of 8 (permalink) Old Mar 27th, 20, 10:21 PM
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Re: Leaking coolant

If you look on the engine side of the radiator below the filler neck you will see a fill line. Usually just over the trans cooling tube.
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