98 K3500 Leak

skills4lou · November 23, 2007

Hey guys. I haven't been here in a long time but I'm back for some more advice. I have a 98 K3500 crewcab with a water leak that comes in around the heater fan on the firewall. NOT antifreeze, just water when it rains. I found two screws in the cowling that seemed to leak, and siliconed them. I also removed the coolant recovery tank and cleaned out the little drain piece behind that on the firewall. There is definitely no leak around the window, but I'm still getting a drip in heavy rain. Any ideas on where to look next?

thanks!

skills4lou · November 25, 2007

bump: anyone have some ideas?

h8tobl8 · November 25, 2007

bump: anyone have some ideas?

I had a 99 suburban that would do the same thing. Come to find out there was a piece missing where the drain comes through the firewall. Can't remember what it was as it's been a while. It may have been like a turn down or grommet or something. It was quick whatever it was. Also the guy put some special sealant on one of the seams under the windshield wiper linkage cover. He said that it was also a problem in some vehicles.

crpowens · November 25, 2007

Is this happening with the heater on or A/C?

skills4lou · November 26, 2007

Neither. I hadn't used the truck for three weeks, then opened the passenger door and water just poured out. I'm waiting for the next rain to find out if the little screws/silicone worked.

crpowens · November 26, 2007

Have you had the windshield replaced recently? I had a similar problem on my wifes Cavalier, and it was a shotty windshield install.

skills4lou · November 26, 2007

No, the windshield has been in for at least a few years. I did find a few interesting things that needed help though:

1. the antenna cable has a large grommet where it goes through the firewall, and that had been pushed out of place--fixed that.

2. at some point there was a large stereo or amp in the truck, and they drilled a hole in the firewall for the power cable--fixed that hole.

3. I also found that two of the screws that hold the long cowl piece down are directly above the fresh air intake for the hvac, and one of them had a little rust. So I fixed them by gobbing some rtv into the holes, reinstalled the screws and added some more rtv for good measure.

Hopefully that takes care of the leak, because from there I think I'd have to remove the fender to see the rest of the cowl. I'll keep ya posted. We are getting some rain tonight, so I'll chck it in the morning ans see where things are.