Cowboycoupe

My new-to-me 98 Silverado Std. Cab is leaking rain water into the passenger carpet on the right-hand side. I've checked, and it is not coolant. It seems to drip down from the area between the blower motor and the heater air distribution box.

I really don't know where the leak is yet, but I need to know if anyone on the forum has removed the cowl panels where the heater and AC air intake is? If so, I wonder if there are any tips for doing this job. I'm thinking there may be leaves or dirt plugging up a drain.

Any help would be appreciated, and thanks in advance.

Cowboycoupe

Well, I seem to be the only one contributing to my threads, but hoping this might help others going down the same road, I decided to take the cowl drain off the firewall and make sure it was cleaned out.

First step is to remove the coolant overflow tank, two bolts and one hose clip on the bottom. Might as well get it right out of the way.

Second step, removed the two small bolts (7mm heads) from the drain assembly, then worked it out of the fender. Found it was fairly clean, but rinsed it out anyway. While I had it off, I ran water from a hose over the windshield, and found it drained out quite well. I stuck the hose in the cowl from the drain side, and sprayed around to clean it.

At this time, I checked in the cab, and found some fresh water, confirming that my water leak is from the cowl.

Not sure whether it's fixed or not, but the next step will be to remove the wipers and then the plastic cowl vent assembly, so that I can check for missing seals or any other way that the water is getting into the truck.

Cowboycoupe

Found out how to remove the wiper arms, so easy on these trucks. As soon as the weather permits, I will pull the plastic cowl vent pieces, and have a look inside.

Can't put the truck in my garage right now, as I have a Mustang convert in there, and the rest of the space is taken up with the usual stuff that ends up in garages.

fparkin

good luck sound like a ac drain plugged up

Cowboycoupe

Not sure where the AC drain is located, or how to access it, but I sure appreciate the tip. I'm going to follow up on this idea.

fparkin

when I work at a garage that happen a lot

Cowboycoupe

Is the AC drain easier to get at from the top, or from under the truck? Anybody know the best way to clean it out??

fparkin

i did them on hoist from bottom using a long skinny screwdriver

Cowboycoupe

Thanks, Fparkin. Soon as I get a chance, I'll get under the truck with a light and try clearing the drains. I gather there's more than one. It's been raining pretty steady lately, so it's not easy to see whether the AC drainsto the road.

Cowboycoupe

I don't have a hoist available to me, and the ground is too wet to get under the truck. My Mustang is up on stands for the winter, so the garage is not available either.

So, today, I took the plastic cowl trim/ven/garnish off the truck. Easy to do, just a few sheet metal screws, unplug the washer hose, remove the wiper arms, and off it comes. Cleaned up in behind, flushed with water, and tested with a hose. Putting lots of water in the plenum below the air intake makes some water drip into the cab. Couldn't see any obvious place where it could leak, but it is very hard to see from the top.

Next step is to find and clean out the AC drain. I'm assuming that if you put a lot of water in the intake, some is bound to get into the heater system. If the AC drain is clear, I'm hoping it just runs right out.

Wish me luck. After this, if I can't fix it, I'm taking it to a friendly body shop guy I know, and am prepared to "write a check" to get a dry cab.