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Where did this water come from?
https://www.slantsix.org/forum/viewtopic.php?t=13139		 Page 1 of 1
Author:  '74 Sport [ Thu May 26, 2005 6:20 am ]
Post subject:  Where did this water come from?
Something very odd here. I replaced the heater core with a new one in Aaron's factory A/C-heater unit in his Dart Sport. After we got the engine running for the first time last week, we ran it through its initial break-in paces. Later, when we were about to go home, I noticed a small puddle of water in the passenger floor. There was evidence it came from directly above the tranny hump and trickled down to the floor. My first suspicion was that the new heater core was faulty. :evil: We have been back to the shop running the engine several more times since then, and each time I look for more water, but there has not been any more since that first little puddle.

Is there any explanation for that?

Jerry
Author:  '74 Sport [ Thu May 26, 2005 7:22 am ]
Post subject: 
Guess I should have mentioned...
The A/C is not installed, so there is no condensation. Also, the car has not been run in over 5 years. Should not be any residual moisture in the housing. The only thing wet coming from the unit, when replacing the heater core, was some anti-freeze.

Jerry
Author:  Dennis Weaver [ Thu May 26, 2005 8:40 am ]
Post subject: 
Did you wet-sand it??

D/W
Author:  slantvaliant [ Thu May 26, 2005 8:40 am ]
Post subject: 
Tears of joy?
Author:  '74 Sport [ Thu May 26, 2005 10:37 am ]
Post subject: 
Dennis, we finished bodywork and sanding 6 months ago. The A/C unit has been out of the car two years. All we did was change the heater core; install the unit; hook up the hoses; fill the radiator; run engine for break-in; turn off engine; revel in our success; put up tools; look at puddle in floor; look at each other with disappointment (dreading what's to come next); go home; return following weekend; notice puddle is dried up; work on carb, valve lash, and manifold issues with engine running several times off and on for two days; notice no more water in floor.

As you can guess, water in the floor concerns me. I certainly don't want to pull the unit out, dismantle it, and then find no leaks in core. I just don't know where else the water could have come from. :?

SV :lol: :lol:

Jerry
Author:  Jon Dahlberg [ Thu May 26, 2005 2:50 pm ]
Post subject: 
Was the car outside at any point? could be the wiper arm gaskets.
Author:  '74 Sport [ Thu May 26, 2005 3:04 pm ]
Post subject: 
Car's been in the shop two years. Wiper arms are in a box, waiting to go back in after car is painted.

I'm convinced it had something to do with the heater core. But for the life of me, I don't understand why it hasn't been leaking since that first run of the new engine. I really don't want to remove it again, but I don't dare run the risk not doing it, just to have it give way again, right after we get the new interior installed with new carpet. :shock:

Jerry
Author:  Jeb [ Thu May 26, 2005 6:40 pm ]
Post subject: 
What does the water puddle smell like. Is there any sweet smells that would indicate ethylene glycol?
Author:  '74 Sport [ Thu May 26, 2005 7:02 pm ]
Post subject: 
The puddle dried up between visits to the shop. We haven't been using an anti-freeze mix for the initial engine testing. Once we are sure there are no leaks, the plain water will be drained and replaced with a mix.

In this case, I guess there's really no other place for water to come from but the heater core. It's just irritating me to no end that I decided to replace it so that it would not come back to haunt Aaron later. :evil:

Jerry
Author:  GTS225 [ Thu May 26, 2005 7:43 pm ]
Post subject: 
Might be a reach, but could it be that the heater hoses weren't sealed against the core fittings, but did seal as the temp came up? If that's the case, it could have squirted through the firewall and drained down onto the floor, only to have you guessing where it came from.

Roger
Author:  '74 Sport [ Thu May 26, 2005 8:36 pm ]
Post subject: 
Hmmm....
I did install a new gasket where the two hoses penetrate the firewall, but I'll have to check and see if any water could possibly get past them (assuming the hose clamps weren't tight enough).

Thanks, Roger, it's certainly something to look at.

Jerry
Author:  Charrlie_S [ Fri May 27, 2005 4:25 am ]
Post subject: 
If you have acess to a cooling system pressure tester (some parts stores have loaners), pressurize the cooling system, with the engine off, and look for leaks.
Author:  '74 Sport [ Fri May 27, 2005 7:03 am ]
Post subject: 
Good idea! I'll have to check around. Maybe I can find a benevolent soul at a radiator shop. What pressure should be maximum for this check?

Jerry
Author:  Slant6Ram [ Fri May 27, 2005 7:58 am ]
Post subject:  Pressure
The rad caps come in 7 lb or 16 lb. You would never see much more than 16 lb at the heater core. Maybe add just a few to the test to be sure, so I vote no more than 20 lb test.

I've never done that kind of testing, so this is guesswork.
Author:  '74 Sport [ Tue May 31, 2005 6:01 am ]
Post subject:  Mystery solved!
I already suspected the heater core, because there aren't any other logical reasons for water to get into the car. But, what had me baffled was that it only leaked the one time, just after the new engine's first start-up. Also, this was a new heater core. We have run the car many times since then, but no more leaks.

Well, we solved the mystery this weekend. We rigged up a tee fitting in one of the heater hoses and attached a pressure gauge. We pumped it up with air until the radiator cap released the pressure into the overflow reservoir (as it should). A quick peek inside revealed another leak from the heater housing. As much as we dreaded it, we pulled the A/C-heater unit out and replaced the "new" heater core with another. It turned out there was a small leak around one of the soldered joints. We're getting to be experts at this. :roll:

Here's a hint from someone who knows...
If you ever have to change your heater core, rig up a pressure gauge and check it for leaks under water, before you even think about installing it, new or not. Our replacement held about 20 lbs for several minutes, with no bubbles appearing, so I hope we are safe now. We would have been extremely upset to have it leak, after installing the new carpet. :evil:

Jerry
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