Where does the water come from?

J Body General Discussion

  1. Yellowdart69

    Yellowdart69 Well-Known Member

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    Where should I look, to find the likely source of the water in the carpet, below the right side of the dashboard? We had a lot of rain this summer. Thanks.
     
  2. jasperjacko

    jasperjacko Well-Known Member

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    If your cowl area is full of debris, and the rubber drainage flaps are clogged, it will back up in the heater box area. Remove the plastic screens at the base of the windshield and clean it out, and make sure the drainage flaps are clear. Another possible leak is if the condensate drain nipple is clogged and the a/c system can't drain water away. It is located on the firewall near the transmission dipstick.
     
  3. BudW

    BudW Moderator Staff Member

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    The first thing I would check, on any F, M or J-body, would be the 3 rubber flaps on engine side of firewall.
    Find one and pull the bottom of flap forward and see if there is a mud like substance caked up behind them. If so, what has happened is debris (dirt, leaves, etc.) piles up behind the flaps and doesn’t allow rain water to easily drain away.

    There are cars (um, could be looking at myself) that I have taken the cowl screen off and have literally scooped buckets and buckets of “stuff” out from the cowl area.

    What happens is rain water enters but can’t exit. Next the rain water then pours over into the AC/Heater air horn (outside air entrance) and right onto the floorboard, via the AC/Heater case.

    Note: I have a similar problem in my wagon. I need to take off the black plastic cowl screen, remove the wiper transmission (and replace the wiper bushings while at it) and get in there with a small Shop Vac hose to clean out as much of the debris that I can. Right now, during a heavy rain, I get water coming out of both outside air floor vents (drivers and passenger).
    Note: my wagon came without A/C so it has an air horn on both sides of cowl. A/C cars only have a air horn on passenger side.

    A person could also use a water hose on medium to low pressure and wash the debris out, as well – but you do risk getting water inside of the car (not like you don’t already have that problem).

    The picture of this M-body, will tell you to look for those rubber flaps (red circles and black circle, behind the engine).
    s-l1600d.jpg

    Generally, if the cowl is caked up with "stuff", the A/C drain tube is also stopped up.
    The drain tube is a black rubber "L" shaped rubber tube about mid way down on firewall and is not easy to get to (white circle).

    Now you might have another source of the water leak – but at least check this first.
    BudW
     
  4. Yellowdart69

    Yellowdart69 Well-Known Member

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    Thanks. I think, that I have been pretty good about checking those drains. But I will check next time I can. The car is put away for the winter, at this time.