I just bought this truck, has less than 100K miles, /6,727 (yes I know a 904 from a 727) and really pretty clean. Yellow numbers from factory still very visible on frame, solid cab, including floor pans, ONLY rust is over the rear wheel wells and even that is slight. Could use a pass. door not because of rust but it's beat up/ faster and easier to plop a door on than all the time it would take to straighten, dented and creased way up high.... PO could hardly see, it seems no garage door jam is wide enough for this guy..... the truck has definitely sat quite a bit over its 35 years. Outside, without moving an inch, for at least 3-4 years since I have known of the truck. PO said it had sat in a barn for 10+ years before he got it 4-5 years ago. (so he says)

anyways when I looked at it before I decided to buy it, the carpet was damp between the door and end of seat on driver side, below the dimmer switch. I didn't think much about it at the time because the door weatherstrips are shot.

well now that it's home, and I am digging into it to evaluate "just what I got myself into" it's rained and snowed a few times. I still have it on a trailer in the driveway, while I searched for an exhaust manifold for it. (the reason it has been sitting before I got it) well last weekend I noticed the driver side of the carpet was quite soaked. pass side isn't. I took the threshold off, and the screws holding the carpet down just forward of the seat edge.(surprisingly came right out, didn't break, weren't corroded at all...… and no, I don't think the old guy PO has ever touched them. all these screws are factory hardware.


so, in looking for the source of the leak, I noticed that with the carpet out of the way, a greenish stain (mossy color) at the floor pan/firewall/A pillar seam. I took out the E brake pedal and the cowl vent in the kick panel (this is a factory non AC truck) and it has rained and snowed some more, since. Hood has ~1-1/2" of partly melted, packed down heavy snow on it right now. Well today, I looked. Minimal wetness in that firewall to A pillar seam (on inside of the cab) but it was "wet". Nobody has been near this truck since the weekend when I pulled that Ebrake pedal and cowl vent panel. (it was in mid 50s and sunny last weekend) The wetness starts about 2/3 of the way up the firewall, just right on the original seam sealer.
Dry above that point.

I did notice that when I opened up the cowl vent on the passenger side, that it is full of pine needles in front of the heater core, that I can see. I've had older vehicles before, where the cowl would fill with leaves, etc I haven't had the wipers and cowl panel off this truck yet.

Now (finally) my questions... why would it be wet, "there"? and why would it start where it does? I don't believe this has been a problem for very long, there is no mold on the jute padding, the floor is extremely solid and in great shape, paint is intact (Ive seen wet cabs before, where the sheet metal goes bare when they have been wet, often)

With the shape the rest of this truck is in, I'm really hoping there is no terminal rust damage somewhere to cause this wetness..... who knows what about these cabs?