coolant leak

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naa10104

Well-known member
Joined
Jul 26, 2014
Messages
446
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1
Location
Reston, VA
My Car
1973 Convertible, matching #'s H Code, Auto
Post: #1coolant leak

Hello,

Have a 73 non AC car. Just replaced the radiator and am 100% certain that the radiator and associated hoses are not leaking. I noticed a small amount of coolant dripping out of the frame rail , passenger side about even with the back of the door. Small amount on the floor about the size of an egg. First thought was heater core but the floor carpet and padding are all dry. No odor in car. Any chance that while swapping radiator some coolant somehow ran down the frame rail and is draining out ? Had to change radiators twice due to defective radiator first time. Any thoughts appreicated.

steve

 
Post: #1coolant leak

Hello,

Have a 73 non AC car. Just replaced the radiator and am 100% certain that the radiator and associated hoses are not leaking. I noticed a small amount of coolant dripping out of the frame rail , passenger side about even with the back of the door. Small amount on the floor about the size of an egg. First thought was heater core but the floor carpet and padding are all dry. No odor in car. Any chance that while swapping radiator some coolant somehow ran down the frame rail and is draining out ? Had to change radiators twice due to defective radiator first time. Any thoughts appreicated.

steve
If the coolant level is not changing, what you've suggested seems reasonable. Chuck

 
Post: #1coolant leak

Hello,

Have a 73 non AC car. Just replaced the radiator and am 100% certain that the radiator and associated hoses are not leaking. I noticed a small amount of coolant dripping out of the frame rail , passenger side about even with the back of the door. Small amount on the floor about the size of an egg. First thought was heater core but the floor carpet and padding are all dry. No odor in car. Any chance that while swapping radiator some coolant somehow ran down the frame rail and is draining out ? Had to change radiators twice due to defective radiator first time. Any thoughts appreicated.

steve
If the coolant level is not changing, what you've suggested seems reasonable. Chuck
Thanks I will keep an eye on it ... wasn't sure if the coolant could get that far back on the frame rail.

 
Freeze plug maybe????????

 
Freeze plug maybe????????
Embarrased to say I only put eyes on the passenger side, but probably not as carefully as I should have. Will double check if this continues ... thanks.

steve

 
What engine is in the car. If it's a 302, it could be conceivable that a coolant leak from the rear of the intake or head could make its way via bellhousing, etc to where you describe.

 
all the above statements are true, could be from several places. since your in VA , and not freezing yet, how about hosing the engine and frame area's off and checking it again.

 
all the above statements are true, could be from several places. since your in VA , and not freezing yet, how about hosing the engine and frame area's off and checking it again.
thanks for the input. It is a 351 C

steve

 
all the above statements are true, could be from several places. since your in VA , and not freezing yet, how about hosing the engine and frame area's off and checking it again.
thanks for the input. It is a 351 C

steve
Hello,

Checked it again yesterday and this time there was app. a 8" diameter puddle under the car in basically the same location under the car but further forward ... about 18" back from the passenger side tire. The coolant level was lower, but more than the puddle on the floor would indicate. Again I checked everywhere and can't locate any leaks. I actually removed the rocker panel and kick panel and pulled the carpet and pad up as much as that would allow. Floor is dry as well as the carpet and pad. I looked at the bottom of the heater/fan box, no indication of any coolant. I wonder if the level in the radiator is lower because some air has "burped" out of the cooling system. Maybe the coolant on the floor is residual from what was spilled/drained earlier. I will check it on my next visit to the garage and see if anymore coolant is on the floor. Will also check engine freeze plugs and head gaskets more carefully. Is it possible for the heater core to be leaking, but not present insdie the car on the apssenger floor ? Any advice is appreciated ... thanks.

 
The heater box has a drain tube that goes through the floor near the hump so a leaking core may not show

inside the car.

Paul
Great ... was not aware of that. I am assuming that it is there exactly for a leaking heater core so the fluid does not damage the interior of the car ? How can I access this drain hose and check it ? I guess I have to remove the heater box (?) to check for leaks ? thanks

steve

 
I believe that hose is primarily for condensation draining on AC cars, not sure if it's there on an on-AC heater box.

Trying laying out a piece of cardboard under the car next time. Keep an eye on it and it and it should tell you exactly where the drips are coming from. Should help you home in on the leak...

 
I believe that hose is primarily for condensation draining on AC cars, not sure if it's there on an on-AC heater box.

Trying laying out a piece of cardboard under the car next time. Keep an eye on it and it and it should tell you exactly where the drips are coming from. Should help you home in on the leak...
I just replaced my heater core (wow) and I can assure you that the heater box is for more than condensation. When the heater core goes bad it will drain through the drain in your heater box and according to how long that tube is could cause the coolant to come in contact with the bottom of the car and appear some place else.

 
I believe that hose is primarily for condensation draining on AC cars, not sure if it's there on an on-AC heater box.

Trying laying out a piece of cardboard under the car next time. Keep an eye on it and it and it should tell you exactly where the drips are coming from. Should help you home in on the leak...
I just replaced my heater core (wow) and I can assure you that the heater box is for more than condensation. When the heater core goes bad it will drain through the drain in your heater box and according to how long that tube is could cause the coolant to come in contact with the bottom of the car and appear some place else.
Hello,

Thanks for all the info. I have had the entire interior out of the car and never remember seeing any kind of drain hose. Again my car has never had AC. When I get back to it I will jack it up and get under it to check for the drain hose and any other possible engine/coolant leaks. There is absolutely no coolant in the passenger compartment floor.

 
I would agree that the drain hose was only for A/C cars so it was not something that came to mind. If it's definitely coolant, next step (which you are already looking into) is to check head gaskets. I encountered an issue once with 351c with coolant leaking from rear of one cylinder head gasket. Re-torquing head bolts eliminated the issue so I never took it further. If that's the case you will find the engine paint discolored from the coolant leak in the area where it is occurring.

Unfortunately this is one of the real PITA issues.

 
Naa,

I would suggest pumping up the cooling system with a pump designed for this purpose and then look for leaks. If you don't have one, typically Advanced Auto Parts or Autozone will loan you one to use. Remember, don't over pressurize the system especially if the radiator is old.

Good luck.

Thanks, Jay

 
Naa,

I would suggest pumping up the cooling system with a pump designed for this purpose and then look for leaks. If you don't have one, typically Advanced Auto Parts or Autozone will loan you one to use. Remember, don't over pressurize the system especially if the radiator is old.

Good luck.

Thanks, Jay
Thanks for all the input. Went to pick the car up today at the garage where I store it ... no coolant on floor. Drove it to a car show app. 25 minutes away with the heat on, 40 degrees out. Parked it at the car show, came back two hours later coolant on ground in same place. Drove it back to garage parked it ... no more coolant leaked out. No coolant odor in car, passenger floor dry. No evidence of coolant leaking from any where else, includiing head gasket. Almost certainly has to be coming from heater core. Does anyone know for sure if a non AC car has a drain for the heater box so that coolant ends up on ground not in car ? I was always under the impression that most 60's - 70's cars heater cores leaked on the interior of the car, passenger floor. At this point think I am going to go ahead and pull the heater box and install a new heater core. As far as I know the currnet core is original. Any input would be appreciated ... thanks.

 
I have a '71, no a/c, no vent tube.

The only reason for the vent tube is to drain condensation. They weren't installed in non a/c cars, a possible leak every 20 years wouldn't be enough of a reason to install one. They look for ways to save pennies on every car and the added expense of a 10¢ drain tube would not have cleared the bean counters.

It's still possible that you had some coolant puddled in the frame rail and moving it and parking it in a different position allowed some more to drip out.

If you find some more on the floor of the garage it would suspect the hose to core connection. I agree with Jay, pressurize the system so you can search and feel around on a cool engine for the source of the leak.

 
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