Coolant leak ....STILL!
Thread Starter
Safety Car
Joined: Oct 2016
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From: Way too effing close to the city.......NRA Life Member!
2022 C3 of the Year Finalist - Unmodified
Coolant leak ....STILL!
I replaced the heater control valve with a new OEM one, I replaced the radiator with a Dewitt aluminum radiator, new upper and lower radiator hoses and I still had a drip/leak coming from the AC/heater area underneath so I did the heater core bypass, Now, I still have a drip/leak from the AC/heater area underneath and from above it looks like a drip underneath the radiator overflow container. My car only has less than 50,000 miles but know it has many years on it. It's tight in that area and hard to see but is it logical to have an overflow container leak on this low mile Vette? I hate leaks. Experience.info appreciated!
Thanks,
OLE442
Thanks,
OLE442
Pro
Joined: Aug 2007
Posts: 707
Likes: 31
From: Pitman NJ
What year is the car? Mine leaked from the plastic overflow tank.
Also, your heater core will still leak, even if the shut off valve is closed. It's still under pressure when the engine is hot, just doesn't flow coolant.
Also, your heater core will still leak, even if the shut off valve is closed. It's still under pressure when the engine is hot, just doesn't flow coolant.
Thread Starter
Safety Car
Joined: Oct 2016
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From: Way too effing close to the city.......NRA Life Member!
2022 C3 of the Year Finalist - Unmodified
I bypassed the heater core just after I put the new radiator in. The heater core and the heater bypass valve should not have an pressure.
After I put the radiator in and re-assembled the rest, none of the hoses or anything to deal with the actual new radiator itself leaked. But, it was dripping back near the heater core/heater control valve. I peeked inside the compartment and it looks like coolant is leaking under the overflow tank so I assume it's the tank. I felt around as best I could and didn't get any fluid on my hand. It's tight in there!!
I guess I'll raise it on the lift, remove the front tire and take the 3 screws out that appear to hold the tank in. I guess after 40 plus years, the plastic could be brittle and have a leak. I'm running out of culprits here....LOL!
Did I mention I hate leaks?
Last edited by OLE442; Jun 30, 2019 at 08:33 PM. Reason: added info
Thread Starter
Safety Car
Joined: Oct 2016
Posts: 3,734
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From: Way too effing close to the city.......NRA Life Member!
2022 C3 of the Year Finalist - Unmodified
Took the tank out and it does have a leak by the lower bolt/clip! Have one on order from ZIP!
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Thread Starter
Safety Car
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From: Way too effing close to the city.......NRA Life Member!
2022 C3 of the Year Finalist - Unmodified
I received the tank from ZIP and installed it tonight. It went in OK but everything on these cars seems to be very packed into tight spaces....LOL! But I got 'er done with a little patience.
Now, I bypassed the heater core with a 1 foot length of 3/4 inch (I think) heater hose from NAPA. It seems like the hose is narrowing down(collapsing) quite a bit from the water pump to the manifold. Is that normal or do I need to get a longer or heavier duty piece of hose? I was also wondering if I should try to make the original hoses connect back and remove the bypass. There was/is no coolant leaking into the interior and is could be most likely that only the overflow tank was leaking in that area? I would like thoughts on this one. What are the odds the heater core could leak on this old of a car even though it's low mile?
Thanks for all your help,
OLE442
Now, I bypassed the heater core with a 1 foot length of 3/4 inch (I think) heater hose from NAPA. It seems like the hose is narrowing down(collapsing) quite a bit from the water pump to the manifold. Is that normal or do I need to get a longer or heavier duty piece of hose? I was also wondering if I should try to make the original hoses connect back and remove the bypass. There was/is no coolant leaking into the interior and is could be most likely that only the overflow tank was leaking in that area? I would like thoughts on this one. What are the odds the heater core could leak on this old of a car even though it's low mile?
Thanks for all your help,
OLE442
Thread Starter
Safety Car
Joined: Oct 2016
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From: Way too effing close to the city.......NRA Life Member!
2022 C3 of the Year Finalist - Unmodified
I don't need my heater and will wait till next spring to deal with that. Spent too much on the car this year so I'll just wait to deal with whether the heater core is OK or not next year.
I did see on other online posts where some C3 owners just capped the water pump and manifold fittings on the motor. The hoses connect to the engine and then go to the heater core.
They used heater bypass caps. That would eliminate the heater bypass hose kinking. They used Dorman 493-100 (5/8inch) and Dorman 493-101 (3/4 inch) with hose clamps to block off those fittings.
Is that an acceptable temporary fix until next year?
Thanks, OLE442
I did see on other online posts where some C3 owners just capped the water pump and manifold fittings on the motor. The hoses connect to the engine and then go to the heater core.
They used heater bypass caps. That would eliminate the heater bypass hose kinking. They used Dorman 493-100 (5/8inch) and Dorman 493-101 (3/4 inch) with hose clamps to block off those fittings.
Is that an acceptable temporary fix until next year?
Thanks, OLE442
Last edited by OLE442; Jul 8, 2019 at 06:04 PM.
Instructor
Joined: May 2018
Posts: 177
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From: pa
I tested my heater core by plugging one of the hoses and made up a tee fitting with a schraeder valve and gauge on the other hose.. put 10 psi in it and it went to 0 psi in a hurry. took the hoses off the heater core and tied the 2 hoses together until I replaced the heater core. not a terrible project. any of the bypasses you mention will work but if you loop a hose between the manifold and water pump make sure it isn't against the hood. p.o of my 71 did that and it blistered the paint on the hood.
Thread Starter
Safety Car
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From: Way too effing close to the city.......NRA Life Member!
2022 C3 of the Year Finalist - Unmodified
So, you're saying to leave the bypass hose on and not to block off the connections on the waterpump and manifold with the Dorman rubber covers?
Drifting
Joined: Jun 2012
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From: Port St. Lucie Fl
it circulates through the block to the water pump without any hoses connecting them. I removed my heater hoses and plugged the ports in the intake manifold and water pump 5+ years ago.
Racer
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From: Cincinnati, Ohio
Race Director
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From: No Where USA
I don't need my heater and will wait till next spring to deal with that. Spent too much on the car this year so I'll just wait to deal with whether the heater core is OK or not next year.
I did see on other online posts where some C3 owners just capped the water pump and manifold fittings on the motor. The hoses connect to the engine and then go to the heater core.
They used heater bypass caps. That would eliminate the heater bypass hose kinking. They used Dorman 493-100 (5/8inch) and Dorman 493-101 (3/4 inch) with hose clamps to block off those fittings.
Is that an acceptable temporary fix until next year?
Thanks, OLE442
I did see on other online posts where some C3 owners just capped the water pump and manifold fittings on the motor. The hoses connect to the engine and then go to the heater core.
They used heater bypass caps. That would eliminate the heater bypass hose kinking. They used Dorman 493-100 (5/8inch) and Dorman 493-101 (3/4 inch) with hose clamps to block off those fittings.
Is that an acceptable temporary fix until next year?
Thanks, OLE442
I have used those with no issues.
Thread Starter
Safety Car
Joined: Oct 2016
Posts: 3,734
Likes: 299
From: Way too effing close to the city.......NRA Life Member!
2022 C3 of the Year Finalist - Unmodified
So, I assume I could just leave the bypass hose between the water pump and the manifold on. It will still flow but is not perfectly round at the curve. Even if it were closed up completely, it would be doing the same thing as the Dorman caps? That would allow me to drive it until I check the heater core out for leaks.
Last edited by OLE442; Jul 10, 2019 at 09:29 AM. Reason: spellin'