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Old 07-09-2020, 05:16 PM   #1
Adamj4130
 
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Default 97 hardbody possible ac evap leak

Now that itís 95į out and billion% humidity, Iím getting a weird leak. Carpet under passenger floor mat is wet, cool to touch. Evap drain is clear, and drains plenty. Evap box is cool to touch, slight condensation on box. No visible dripping or wet path that water is running. Any ideas???
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Old 07-10-2020, 01:34 AM   #2
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Originally Posted by Adamj4130 View Post
Now that itís 95į out and billion% humidity, Iím getting a weird leak. Carpet under passenger floor mat is wet, cool to touch. Evap drain is clear, and drains plenty. Evap box is cool to touch, slight condensation on box. No visible dripping or wet path that water is running. Any ideas???
Possibilities,? cool to touch, sure the box is draining, ? maybe draining AND leaking? OR Windshield leak, unlikely? OR Heater core leaking? Hey. I HOPE not! You could bypass it to find out. OR..Neighbor's cat is sneaking in at night and peeing on the carpet? If so, install a small lead pellet behind the cat's right ear. Here is the tool to install that pellet.
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Old 07-10-2020, 01:42 AM   #3
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The drain for the evaporator box is probably plugged up. If you look under the truck you'll see it coming out of the passenger side firewall. A coat hanger works well for getting it unclogged, but go slow and be careful not to poke a hole in the evaporator core.
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Old 07-10-2020, 03:50 AM   #4
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I'm going with drain plugged like SBJ suggested. If your AC system were leaking it would come.out as a gas and it wouldn't be making anything cool.
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Old 07-10-2020, 12:36 PM   #5
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Yeah, I have seen this problem before. I might bet that when a water leak happens, it's not a drip, but a sudden big splash on the floorboard.

Inside your heater core box, just below your glove box, take off the outer housing. It isn't that hard to do.

On the left (drivers side) of the box down low...you will see a channel in the box like a little trench. There is a black drain hose hooked to the end of it, and this hose drains out onto the ground through your firewall.

You have to dry out the inside of the box and clear the hose. It gets choked up with dirt and little debris, and then the condensation builds up inside the box, finally draining out onto the floorboard when it reaches a certain level.

After you clear the hose, clean the bottom of the channel in the box out, carefully remove any twigs, leaves, or pine needles caught in the fins of the core. It is normal for water to be in the bottom of the heater core box, but if the channel is full of crap and the hose is blocked, all that water ends up on the floorboard. Dust over the years and other crap builds up in there. There is a seal halfway or so up the box, so when the channel and hose are plugged, the water builds up and then comes out between the seal.

Basically...to fix this you pull off the front plastic cover of the heater core box, clean out the crap from everything and dry it with rags or whatever.

The hose is at the end of the box on the drivers side of the box. Pull it toward you with a needle nose until it comes free. Clean it out. Stick it back through the hole and make sure it goes through the firewall hole and down. Problem solved. I had to do it on the Teal Terror once. After 21 years of dust and gunk, it started to do the same thing.
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Old 07-10-2020, 04:51 PM   #6
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It’s definitely draining out of the hose going into the firewall... confirmed by the big puddle of water under the truck when parked , not to mention visually seeing it drip. However, when I reach behind the plastic evap box under glove box it’s wet with condensation. It this normal or do you think it’s leaking at a seal?

Guess I’ll take the glove box out and dig in...
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Old 07-10-2020, 07:47 PM   #7
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Update- took off the glove box, took off the metal plate, took out the thermo-resistor(?), and the clips on the front of the box enough to get a good look in there. On the passenger side of the box, there was a little dirt and leaf debris, but dry. On the driver’s side/drain side, dry with the exception of a little wetness in the bottom back by the drain- and this was after on and off city driving with ac running for about 4 hours. It doesn’t appear to have been clogged and filled up. It was surprisingly dry in there. Vacuumed out the dirt and put it all back together. Still had a good amount of condensation on the back outside of the box from the drive.
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Old 07-12-2020, 02:10 AM   #8
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My pathfinder had heavy condensate on the outside of the evap box last week. Temps here have been in the 90s with 75 to 100 percent humidity and a dewpoint hovering around 72. Absolutely miserable. Id say it is probably normal.
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Old 07-13-2020, 09:52 AM   #9
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Quote:
Originally Posted by Adamj4130 View Post
Update- took off the glove box, took off the metal plate, took out the thermo-resistor(?), and the clips on the front of the box enough to get a good look in there. On the passenger side of the box, there was a little dirt and leaf debris, but dry. On the driverís side/drain side, dry with the exception of a little wetness in the bottom back by the drain- and this was after on and off city driving with ac running for about 4 hours. It doesnít appear to have been clogged and filled up. It was surprisingly dry in there. Vacuumed out the dirt and put it all back together. Still had a good amount of condensation on the back outside of the box from the drive.
Seeing what you found and that you are getting condensation on the OUTSIDE of the box tells me you don't have a clogged hose. Did you check the outgoing hose underneath the truck? Is it pointing down? Is the round rubber ring gasket through the firewall in place properly? I think there is another one on the hose itself, where it comes out the back of the box. Lay a piece of newspaper in there and try to identify where the drip is actually coming from, and how frequent it is.

If it comes from the back of the heater core box, the ring seal on the hose is missing or not in place properly. The one installed into the back of the box. Both the box seal and the firewall seal have to work.

You also might consider flushing the whole cooling system, in case the heater core is partially clogged. Easier for it to clog there then the radiator or water jacket passages.
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Old 07-18-2020, 08:51 PM   #10
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Both seals on heater/coolant lines seem good, and coolant was flushed and changed recently.
Today I was wearing sandles and felt cold water drip on my toes while driving, seems like it came from the floor vents.
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