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Topic: coolant leak

in Forum: C3 Cooling and Heating Systems


coolant leak

Posted: 6/28/05 5:31am Message 1 of 5
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TOPTON, PA - USA
Joined: 5/5/2002
Posts: 313
Vette(s): 71 454 convertible, mulsanne blue,a/c, matching numbers, 48K miles

I have recently noticed I have a anti-freeze leak and am trying to troubleshoot it.

Here are the facts.

1. When the car is in the garage before being started, no leak

2. I start the car and about 2-3 minutes after startup I get a drip (one every 2-3 seconds.)

3. I take the car for a couple mile run, bring it back in the driveway still running and the leak is not there anymore.

I have checked the radiator hoses and have not located a leak. I have not been able to get it anywhere on a lift to look at it. Could it be the water pump? Could it seal itself after getting warm?

Also, if I let the car sit a few hours and it is still warm and start it up, it does not leak.

The antifreeze level in the overflow tank is not that low either.

Please help with any suggestions!

 

Thanks




Tom
71 454/365 Mulsanne Blue Convertible


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coolant leak

Posted: 6/28/05 7:32am Message 2 of 5
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Frederick, MD - USA
Joined: 9/8/2003
Posts: 3398
Vette(s): 1969 convertible L71 427/435 4-speed black interior
Get the radiator (and the cap) pressure tested. If the system is OK, it should hold pressure for several hours minimum. If thre is an external leak, it should show up visually. If it loses pressure and no leak appears, then you have an internal leak such as a blown head gasket or cracked cylinder head. That doesn't sound like it's your problem. If the radiator cap doesn't hold pressure, it's simply a matter of replacing it.

The water pump has a weep hole it will leak from if bad, or from the edge if a gasket is broken. Either way it should be visible. If the water pump bearing is bad, it would normally make noise though not necessarily leak.

You may simply have had too much coolant and it's gone out the overflow until it reaches its proper level. The overflow tank itself could have a crack or split from age and the coolant leaks from there until it gets below the level of the crack or split.


coolant leak

Posted: 6/28/05 9:02am Message 3 of 5
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Newark, DE - USA
Joined: 7/26/2004
Posts: 468
Vette(s): 1968 Conv, 454HO,500HP-600TQ, TKO-600,3:70 HD rear,hotrod air, custom paint & suspension,1973 Ruby Red,T-top, 383 Stroker, TK)-500,frame off restro, 1967 Dodge Coronet, 340 stroker to 406, Dana 60

Could be your water pump cold it'll leak when it gets warm it swells just enough to stop the leak . If it is the pump bearing it'll get to where the leak will be all the time. Start your car & when you first see the leak shut it off ...put on some leather cheap gloves & feel below the pump & on the bottom of the pump pulley. By putting a sheet of cardboard under the engine first you should be able to tell approx where the leak is coming from (FRT, REAR, RT side ,etc.) If all else fails put it on jack stands in the front & crawl under.

Good luck

Alan




                                               

coolant leak

Posted: 7/6/05 12:37pm Message 4 of 5
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CUYAHOGA FALLS, OH - USA
Joined: 12/2/2003
Posts: 6424
Vette(s): 1975 C3 Red, T-Tops, Black Interior. All I need is time and money! Getting there!
You may want to go to AutoZone or the equal, and use a cooling system pressure tester.   You connect it to the radiator, and pump up some pressure.  That will help show up the leak.    You put a deposit on the tester, and get a full refund when you return it.


coolant leak

Posted: 7/7/05 4:58am Message 5 of 5
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TOPTON, PA - USA
Joined: 5/5/2002
Posts: 313
Vette(s): 71 454 convertible, mulsanne blue,a/c, matching numbers, 48K miles

Finally got a chance to jack up the car high enough to get under it and be able to really get a look. It turns out to be the lower radiator hose connection to the water pump. It runs down the hose and drips on the ground not directly above the actual leak which had me thinking it was coming elsewhere. Thanks for all your input, I'm glad it wasn't the water pump!

 




Tom
71 454/365 Mulsanne Blue Convertible


in Forum: C3 Cooling and Heating Systems


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