I recently purchased a 1996 Cherokee Classic. Both floorboards were rusted pretty bad and when I did a water test I saw the water running down the firewall. I did the following based on the posts in this forum:

- sealed blower motor housing inside engine compartment
- cut open the cowl and sealed around the fresh air intake
- sealed body seems in the upper right corner under hood
- sealed antenna grommet

I purchase new floor pans and welded them in but after I did another water test after doing all of this I still see water dripping down the passenger side firewall almost in the corner. I am at a loss of what to do next other than apply sealant on the inside. It seems that the water is coming from the blower motor housing that I sealed but I also see it leaking a bit higher as well. I appreciate any suggestions.

 

Check along the windshield as best you can. Rust can take hold under the seal and rot thru, water will run down the A-pillar to the floorpan. Water can run from one side of the vehicle to the other and then leak thru, so take that into consideration. Check the rain gutter above the door and the door seals themselves, as well as the roof rack if you have one as the holes in the roof can leak also. You can use a garden hose with a sprayer and hit the areas you suspect are leaking. Helps if you have a friend spray it while youre on the inside watching for leaks.

 

I checked the window seems by spraying soapy water along the seems on the outside and then blowing air from the inside at the seems and looked for bubbling, but I did not see anything. I'll check the roof rack and A pillar but I mostly spray it on the front when I test it - about mid windshield and lower.

 

I would suspect windshield. Do you have all your windshield moulding pieces intact?

 

Yes, they are all intact. I am noticing when I crawl inside, water is leaking from the foam seal around the blower motor. I don't want to seal it from the inside as I think that is a band-aid and would rather seal it from inside the engine compartment.

 

I would say the foam seal could be the culprit. try using the foam seal to make a rubber one out of an old inner tube and see if that seals it up

 

So to make a foam seal I have to pull the entire heater core/plenum assembly out, correct? I searched on how long it takes to do that and most say about 4 hours. Would you recommend doing that?

 

I mean the foam seal around the blower motor. The one that you mentioned. I am assuming you mean like a big circle shaped foam seal that mates the blower motor to the box right?

 

So I sealed the foam seal with silicone; this is the seal that goes between the blower motor housing and the firewall. I sealed it from inside the engine bay. But when I go inside the vehicle I see a foam seal at the blower motor and that is still wet. So I am guessing my silicone sealing did not go well or I missed something. However, when you said to replace that seal I was under the impression that you have to take the entire heater core out in order to do that, unless there is an easier way to separate it from the firewall.

 

i honestly dont know if there is an easier way. but it may need to be done if thatsa where the leak is coming from. water leaks can be infuriating

 

Well after receiving many replies and doing further thought and investigation on this issue I have what will be my next steps:
1) I went to a junk yard that had a 1993 cherokee and looked at the blower fan motor area. I noticed the entire section was sprayed with what looked like undercoating (when I get a chance I'll post a picture). So I ordered that "As Seen on TV" flexseal paint spray. Was going to use regular undercoating you can find at any auto parts store but I thought I would give this a test. It says it can hold up in temperatures from -80 to 350 deg F. I will spray the entire firewall and fan area with this.
2) I also ordered a can of flexseal liquid paint. I am going to pour it into the top cowl area where most people cut open to seal the fresh air intake. But my focus is to have it seal where the water drains out through this area. I am also going to try and pour it down the right and left lower rocker panel as these are drainage areas for water coming from the front. There are holes in the bottom of this so I will make sure it does not seal those up.

I will post back when I have done all this and tested it.

 

Resurrecting an old thread! -Mdownesx, Did the flexseal work for you? You may not remember or answer this as it was a while ago!

 

I sold that Jeep a few years ago. My daughter was very upset but that lasted maybe a couple weeks until she got a car that didn’t have issues all the time. Anyway, I never used the flex seal. If I recall, the sealing around the top cowl and blower fan seemed to stop it to a very slow drip that we lived with. Hope this helps.