Coolant Leak
Thread Starter
Intermediate
Joined: Mar 2021
Posts: 26
Likes: 6
From: Tampa, FL
Coolant Leak
Looking for some expertise on cause of this coolant leak from underneath my 1979 C3 corvette. I just replaced water pump and it does not appear to be leaking, all hoses and t-stat also look good, no leaks. Any guidance is appreciated. Thanks!
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
If I had to guess, I would say either where the Lower Rad Hose attaches to the W.P. or
where the heater hose attaches.
Drain just enough coolant off to be able to work on those hoses. After removal, you can smear some Permatex RTV clear around both of those ports.
Slip the hoses back on and rotate the hoses180 degrees to evenly coated the RTV.
Clamp it. Let it sit for several hrs before refilling.
As for clamps. The ones that require a socket or nut-driver are superior for brute clamping force. Stainless all the better.
where the heater hose attaches.
Drain just enough coolant off to be able to work on those hoses. After removal, you can smear some Permatex RTV clear around both of those ports.
Slip the hoses back on and rotate the hoses180 degrees to evenly coated the RTV.
Clamp it. Let it sit for several hrs before refilling.
As for clamps. The ones that require a socket or nut-driver are superior for brute clamping force. Stainless all the better.
Last edited by HeadsU.P.; Sep 17, 2022 at 06:26 PM.
Race Director
Joined: Jul 2015
Posts: 13,082
Likes: 3,399
From: SW Florida.
did you replace the water pump because of this leak, or did the leak start after you replaced the pump? sounds like you replaced the pump and the leak started. take the WP pulley and belts off and you will either see where you effed up with a gasket on the install or peeing out the weep hole behind the bearings cuz it is a new pump with a bad seal. or it was assembled badly and somebody effed up the gasket on the plate on the back of the water pump. my first 75 had the orig pump. the plate on the back rotted through. i really doubt even the dumbest min wage new employee who never saw a water pump before would not notice that. but possible.
Last edited by derekderek; Sep 18, 2022 at 05:48 AM.
Drifting
Joined: Dec 2020
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From: Central Florida
2024 Corvette of the Year Winner - Modified
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Looking for some expertise on cause of this coolant leak from underneath my 1979 C3 corvette. I just replaced water pump and it does not appear to be leaking, all hoses and t-stat also look good, no leaks. Any guidance is appreciated. Thanks!
https://youtu.be/uN-V1e_9QnA
https://youtu.be/uN-V1e_9QnA
Racer
Joined: Oct 2021
Posts: 436
Likes: 15
From: Maryland
@Sdh91 before u trial and error this repair, try to trace it and find the source first. What helped me was first drying off all of the affected areas, removing as many components from the front of the engine as possible (air pump and compressor for me), running it till it leaked, shutting off the engine and tracing the leak down visually. Might take u multiple trials but once u find it you'll be set. My thread was here https://www.corvetteforum.com/forums...lant-leak.html
Thread Starter
Intermediate
Joined: Mar 2021
Posts: 26
Likes: 6
From: Tampa, FL
Solved!!!
Appreciate everyone’s input. Turns out it was the hose from the reservoir tank to the radiator. The connection under the radiator cap had a leak. I discovered this by running the car with the ac/heat off, no leak. When I turned on the ac is when I noticed the leak. Put on a new hose clamp and problem solved.
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Drifting
Joined: Dec 2020
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From: Central Florida
2024 Corvette of the Year Winner - Modified
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Appreciate everyone’s input. Turns out it was the hose from the reservoir tank to the radiator. The connection under the radiator cap had a leak. I discovered this by running the car with the ac/heat off, no leak. When I turned on the ac is when I noticed the leak. Put on a new hose clamp and problem solved.
