# Water Leaking on Passenger Floor



## Justins1171 (Oct 27, 2011)

I've got a 2006 Mercury Milan that is starting to leak water on the passenger floor when A/C is on. Doesn't matter if the condenser is on or not. When I turn, it makes a hissing sound. I have WeatherTech floor mats in my car and can isolate the problem to when the A/C is on. I'm pretty handy and not looking to drop over 100 just to have someone look at it.


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## SPS-1 (Oct 21, 2008)

When your AC is on, humidity condenses on your evaporator coils. It drains to under your floorboards. The drain is messed up. It may (or might not be) a hose coming off the AC coil area. Might want to try to google or buy a repair manual to see how the AC is supposed to drain.


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## 47_47 (Sep 11, 2007)

Drain is probably plugged. Look at the firewall. You will see either a 90° open end hose or just a short straight open end hose from the hvac box. Carefully insert a piece of stiff wire to clear the drain. Don't go in more than 2" through the firewall or you could damage the evaporator. Try not to get wet.


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## Justins1171 (Oct 27, 2011)

47_47 said:


> Drain is probably plugged. Look at the firewall. You will see either a 90° open end hose or just a short straight open end hose from the hvac box. Carefully insert a piece of stiff wire to clear the drain. Don't go in more than 2" through the firewall or you could damage the evaporator. Try not to get wet.


Tried to unplug, no luck. Drain was clear. Water still continues. Thinking that the drain line is cracked or disconnected up under the dash along the firewall.


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## noquacks (Jun 5, 2010)

Right- may not even be the drain!! Just experienced this on a 98 Voyager- ended up the drain/tube was perfectly fine- it was the big black box encasing the entire evaporator/cooling unit!! Chrysler is famous for it, but doesnt exonerate other brands, I figure. If the case is cracked like it was in my car, shessh- youre looking at removing the evap unit! Not sure on how to remove on your car, but usually, its a big deal- gotta remove the whole dash.

AND, that means recover the R134a, then do the ac all over again (new dryer, evacuate, new gas).


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## Justins1171 (Oct 27, 2011)

noquacks said:


> Right- may not even be the drain!! Just experienced this on a 98 Voyager- ended up the drain/tube was perfectly fine- it was the big black box encasing the entire evaporator/cooling unit!! Chrysler is famous for it, but doesnt exonerate other brands, I figure. If the case is cracked like it was in my car, shessh- youre looking at removing the evap unit! Not sure on how to remove on your car, but usually, its a big deal- gotta remove the whole dash.
> 
> AND, that means recover the R134a, then do the ac all over again (new dryer, evacuate, new gas).


So if there is a "big black box" that encases the evaporator an it's cracked but the evaporator works fine, can I just patch up the box? It may sound like a simple solution to a possibly complex problem but I'm not able to invest in an A/C unit.


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## cjm94 (Sep 25, 2011)

That car has a foam seal between the box and firewall that leaks not much for parts but a lot of labor pulling dash and box. Not real DIY friendly. 6-8 hours in a shop.


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