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Q: water leaking on to the floor under dash on passenger side on 2004 Mitsubishi Endeavor

everytime we run the ac on the endeavor water pours out from under the dash onto the passenger side front floor
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Important Background information:
I just finished fixing the water leak on my girlfriends 2003 Mitsubishi Eclipse (with an automatic transmission). The dealership will tell you that they have to rip out the dashboard and it takes 10 hours labor which will cost you around $1000. I ended up taking apart the whole dashboard and let me tell you IT IS A JOB! However, in hind sight and actually getting my hands dirty I can tell you that this is not the case and there is a MUCH faster way of doing it yourself.

The problem was the typical Mitsubishi owners complaint which is “water is leaking onto the floorboard due to a/c condensation from a clogged drain hose”. This problem occurs most frequently because Mitsubishi considers a blower motor housing filter (which they refer to as a cabin air filter) as an “accessory”. What occurs as time passes results in leaves, twigs, and other miscellaneous debris gets sucked into the assembly and clogs the evaporator drain hose causing the water to backflow into the passenger cabin. They have been having this problem on just about every model for quite some time and still haven’t really taken any steps to mitigate this problem. I am a Ford owner so I may be a little biased but Mitsubishi really had their heads up their ass on this one… When I walked in I noticed an accessories booklet for the newer 09 lancers and guess what? They still consider the cabin air filter an “accessory”. I would highly recommend any Mitsubishi purchase the “cabin air filter” as it will save owners A LOT of hassle and time. BE SURE TO GET THE MOUNTING BRACKET!!! As far as I’m aware of the filter + bracket combination is a dealer only item (when we went to auto zone to save money on the parts all they sold was the filter). The part number is MR500360 or something like that and it costs around $50 (IT IS WORTH ITS WEIGHT IN GOLD AND WILL PREVENT ANY FUTURE PROBLEMS!!!!!!!).

Fixing the problem:
I would recommend a 3 stage approach to be sure you completely fix the problem and it won’t come back.

1. Installing a “cabin air filter”:

You will have to remove the glove box(you can bend the glove box just enough to enable removal by applying pressure on the left side of the glove box until the post is clear from the glove box backing(then do the same to the right side)). This will cause the glove box to drop down so you can just pull it out.

Then you remove the glove box backing (should be 4 screws or something like that).

Once those are out of your way you should be able to see the blower motor housing (big black thing that’s round at the bottom). Locate a rectangular plastic plate (should be about half way up the blower motor housing). If there are screws connecting a piece (that looks like it can slide out) to the blower motor housing then you have a filter bracket in place (You should remove the 2 screws and pull the bracket out (towards you) to ensure it has a filter in place (or that it isn’t too dirty/destroyed that its failing its function). If you don’t have a filter you will have a rectangular plate that you will have to cut out (I used a razor knife and a bit of force. I banged up my knuckles pretty good so be careful). Then slide the filter tray/bracket into place and use screws (the dealership said they are 4x16 screws. I ended up using 8 x ¾ from my local hardware store so feel free to play around with it) to secure the bracket into the blower motor housing.

Installing the filter will prevent further problems. If you do NOT do this step your problem will more than likely continue!

2. Cleaning out the debris from the evaporator case:

A little background:

You will be cleaning the debris out the lower evaporator case. This is to purge the debris that could potentially clog your system again. If you should decide to take it to a mechanic DO NOT let them deceive/misguide you! In some cases they may insist they need to drain the coolant from you’re a/c system (THIS IS NOT THE CASE!!!!!). The evaporator does NOT need to be removed or even touched! You only need to remove the debris from the lower evaporator case (a plastic downward slanting pan beneath the evaporator).

There are a couple ways to get to the evaporator case.
- You can probably just get away with removing the channeling (may not allow for very much working room but it could potentially save you HOURS and frustration).
- You can disassemble the center console to allow yourself more room to work (what I ended up doing)

Option 1: (probable short cut)

With the glove box removed you should look for a piece that connects the blower motor housing to the evaporator case (should slant downwards as it approaches the evaporator case). This will have likely 2 bolts and a nut (the nut is down at the base of the plastic channel (to the left on the side closest to the evaporator case). The first bolt should be located on the left side behind the dashboard hang down piece for the glove box (support structure/outline …thing. I’m sorry I could not explain this better)(this bolt is kind of a pain to take out as there is not a lot of space between the bolt and the dashboard). The last bolt will connect the plastic channel and the blower motor housing. Finally, disconnect the connector from the top of the channel. The channel should then just slide out which will grant you access to the lower evaporator case!

Once you have the channel removed you can try to use a vacuum or something to clean the debris out (it will have to be a small hose and a decently powerful vacuum). If you cannot clean it out you may have to remove the screws and clips (clips were on the driver’s side in my case) at the base of the evaporator case (the screws go all along the base of the case).

****Here’s the tricky part!!!!!****

To gain access to the 2 screws underneath the center console u may need to remove/bend back the plastic piece of the center console/trim or remove it all together depending on how much working room you require. To bend it back you must remove the screw and the clip. The round piece of the clip pulls out allowing you to compress the back of it together which should allow the clip to pull right out. After you remove those you should be able to pull the plastic out far enough to gain access to the screws in the center.

If you CANNOT access the screws in the center you will need to remove this piece all together. To do that you must remove the clip and screw from the other side as well as the clip holding this piece to the cup holder/gear selector section. That should be located underneath a plastic piece to the left of the gear selector. Then you must release the side clips as well by squeezing/maneuvering the now loose plastic console (you may have to remove the cup holder/gear selector piece as well in order to pull the other plastic piece out).

Removing the screws and clips will allow you enough wiggle room to bend the tray downward enabling you to fit a larger vacuum/cleaning tool. I was not able to completely remove the tray because I was not able to undo the things that were holding it from the rear due to a lack of working room and motivation.

In my case there was also deposits of a gray material which may have either been dust of mold on the evaporator (the metal radiator looking thing). I cleaned the substance off of the evaporator using a wire brush/tooth brush (for those hard to reach areas). BE CAREFUL NOT TO DAMAGE THE EVAPORATOR! The result I believed I achieved by this action was a slightly higher airflow through the vents since it wasn’t being choked off along the way. I also did it because I was unsure if it was mold or not (health concerns etc…).

Option 2 (disassembling the dash):
I will not detail the location of the bolts for this option since it would be too time consuming and most likely is not necessary. If you require this option I would recommend you buy a Chiltons manual for your vehicle (or an equivalent of Chiltons).

This option follows the same process as option 1 except you disassemble the dashboard first and pull it forward/out to get it out of the way (A fair warning. If you take this option you will have to disconnect the battery and allow it to sit for about 2 minutes because you will be removing the airbag assemblies and you don’t want them accidentally discharging. This option also requires the removal of the steering wheel so you will need to mark the position of the wheel before removal (this ensures the correct position/relation of your steering wheel to your wheels). This option has the added benefit of more room to work and access to more of the evaporator case.

3. Unclogging the drain:

There are 2 ways to go about cleaning the drain hose clog. You can do it from the inside or the outside. Since unclogging it from the inside requires you rip apart the entire dashboard and possibly removing the evaporator (requires draining the coolant (by a certified mechanic/shop)) I would highly suggest doing it from the outside!

To unclog the drain hose you can use compressed air, coat hanger, or anything else you can conceive. Since you will be doing it from the outside be sure to remember whatever method you use will push the debris inside (so it may get messy if you use compressed air but it is not a bad option!!! Just be prepared).

You will be able to locate the drain hose/pipe behind the engine on the firewall (will be really close to where the steering column will enter the engine bay). IT IS VERY HARD TO SPOT as it is not very big (In addition the hose will likely be black and the firewall is black)!!!! So be sure to use a good flash light.

The firewall padding may also obscure the drain pipe/hose so you may have to mess with that as well.

Once you find it use your preferred method to unclog it (***fair warning***! If u decide to use a coat hanger be VERY careful not to apply too much pressure as you may do damage/puncture your evaporator!).

Once you are done with that you may try vacuuming out the lower evaporator case again just to be sure it’s cleaned out well. Then you put everything back together and enjoy!

Thank you for taking the time to read my detailed explanation and I hope my explanations helped. PLEASE, if you see anyone who needs help ANYWHERE, do them a favor and copy paste/refer them to this information.
I have put a fan motor on because it quit blowing heat or air out now you can hear water sloshing around and it comes out I think the line is stopped up
In addition to David's comments on the condensation issues and repairs, we extended the drain down the firewall. Mitsubishi has a service bulletine that says because the drain is flush with the firewall on all of these vehicles, air turbulence under the hood also causes problems with proper drainage. The air flow under the hood forces the condensation back inside the car. Eclipses have a seal made out of some type of material around those drains and that material goes bad, so you have to seal around the drain opening. But we extended our drain with 5/1`6 " rubber fuel line and a 90 degree barbed hose fitting that we pushed into the drain opening and ran down the firewall and sealed around it with Gas tank repair putty made by permatex.
scroll down to message #7 - pictures are included in post
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