coolant leak

[naa10104]

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 foe the source of the leak.

Again, thanks for all the info. All good stuff. At this point pretty certain not left over coolant coming off the frame rail. Positive it is not leaking on the firewall side of the engine compartment at the heater core connections. Is it possible that the heater core is leaking either at the connections or in the body of the core but not showing up inside the car ? I believe I will try to put the cooling system under pressure next week and see if I can locate the leak. Thanks again.

 

[piper62j]

Borrow a cooling system pressure tester from a shop, a friend or (not sure about this) Autozone or Oriellys.. Pump it up to the 14lb limit of the radiator cap or less if possible and watch the gauge. If pressure starts to drop, begin looking up under the front end for a leak.. you will definitely find it.. It's possible one of the heater hoses is leaking at the heater core outlet pipe.

To the best of my knowledge, if your car is non ac,, there is no heater drain hose that I can remember.. It only comes with the AC vehicles due to evaporator condensation. One of my 73 Mach 1 cars has no ac and no drain hose..

 

[midlife]

I wonder if the car was originally an AC car, and had the AC system ripped out, leaving only the heater box for the AC system, which may account for a puddle from the heater box itself via the drain. Is there a Marti Report for this car, and if so, does it indicate AC or not?

 

[naa10104]

I wonder if the car was originally an AC car, and had the AC system ripped out, leaving only the heater box for the AC system, which may account for a puddle from the heater box itself via the drain. Is there a Marti Report for this car, and if so, does it indicate AC or not?

Hello,

Not an AC car according to Marti report, have checked the heater core hoses on firewall side. All looks fine there, actually replaced both heater hoses app. on eyear ago. Leaning towards bad heater core,(probably original). Just don't understand why coolant is not showing up on passenger side floor as it usually would. Glad it isn't ! Will pressure test in next couple of weeks. Thanks

 

[naa10104]

I wonder if the car was originally an AC car, and had the AC system ripped out, leaving only the heater box for the AC system, which may account for a puddle from the heater box itself via the drain. Is there a Marti Report for this car, and if so, does it indicate AC or not?

Hello,

Not an AC car according to Marti report, have checked the heater core hoses on firewall side. All looks fine there, actually replaced both heater hoses app. on eyear ago. Leaning towards bad heater core,(probably original). Just don't understand why coolant is not showing up on passenger side floor as it usually would. Glad it isn't ! Will pressure test in next couple of weeks. Thanks

 

[Bill73Ragtop]

Just don't understand why coolant is not showing up on passenger side floor as it usually would. Glad it isn't ! Will pressure test in next couple of weeks. Thanks

Possible leaking from a pinhole in the hose on the engine side of the firewall and the coolant is following the sheet metal contours. You have a tough one to unravel.

 

[naa10104]

Just don't understand why coolant is not showing up on passenger side floor as it usually would. Glad it isn't ! Will pressure test in next couple of weeks. Thanks

Possible leaking from a pinhole in the hose on the engine side of the firewall and the coolant is following the sheet metal contours. You have a tough one to unravel.

Thanks .. we shall see

 

[Don C]

It's also possible that one of the tubes is leaking where it connects to the heater core and the foam seal is functional and keeping it from entering the heater box.

 

[naa10104]

It's also possible that one of the tubes is leaking where it connects to the heater core and the foam seal is functional and keeping it from entering the heater box.

Thanks !

 

[naa10104]

It's also possible that one of the tubes is leaking where it connects to the heater core and the foam seal is functional and keeping it from entering the heater box.

Thanks !

Hello,

I borrowed a cooling system pressure tester and went to the Mustang. No new leaks underneath. Hooked up the tester and pumped it up to about 20lbs. The needle started to drop very slowly and I heard a leaking/hissing noise coming from the engine compartment. Went to heater hoses and found that they were both leaking very mildly between the hose and nipple. One was a little worse than the other. Snugged both of them between 2-3 turns and the leaking stopped. I was surprised as I am always the guy that over tightens everything. I also snugged all the other hoses and double checked ... everything seems fine now. Have not been able to take it for a test drive but hopefully this will take care of it and nothing else will let go since the system is tight now. Thanks for all the advice !

 

[Don C]

What you experienced is what is called plastic creep. You tighten the clamp down and it's nice and snug. A few heat/cool cycles later the material under the clamp has deformed and then along comes cooler weather, everything shrinks (or shrivels) and you have leaks. It's very common for leaks to occur when the weather turns cooler and you use gear or screw clamps. This is why most cars come with the spring clamps from the factory.

This can also happen with harder materials. Aluminum comes to mind. Aluminum wiring was allowed in dwellings for a time back in the '60s or '70s. The wire would deform and creep out from under the screws in fixtures, leading to poor connections and fires.

 

[midlife]

What you experienced is what is called plastic creep. You tighten the clamp down and it's nice and snug. A few heat/cool cycles later the material under the clamp has deformed and then along comes cooler weather, everything shrinks (or shrivels) and you have leaks.

So that explains a lot for us older guys...lollerz

 

[naa10104]

What you experienced is what is called plastic creep. You tighten the clamp down and it's nice and snug. A few heat/cool cycles later the material under the clamp has deformed and then along comes cooler weather, everything shrinks (or shrivels) and you have leaks.

So that explains a lot for us older guys...lollerz

Very funny ... I can't remember if the tubes coming form the heater core are plastic or some kind of metal. Just hope this takes care of the problem. Thanks again for everyone's input. Merry Christmas !!