Water getting in

[Scott Delaney]

Every time it rains I get a little water in the drivers foot well. I believe this large hole may be the culprit.

What is supposed to go there? Seems like something's missing.

Any thoughts would be greatly appreciated.

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[gmbellew]

that is an access hole for swapping the wiper motor. there are drains that should let water out of there.

do a search....I think I have seen some threads discussing the various drains and how water can get in.

 

[gotyourgoat]

Take a look at these threads.

https://www.gmsquarebody.com/threads/apb-check-your-cowl-seam-seals.29801/

https://www.gmsquarebody.com/threads/water-on-floor.15825/

 

[Scott Delaney]

that is an access hole for swapping the wiper motor. there are drains that should let water out of there.

do a search....I think I have seen some threads discussing the various drains and how water can get in.

Thanks. I did a search and got a better idea of what I'm looking for.

What's the best way to examine the cowl drains? Which I guess is a way of asking WHERE are the cowl drains I should be looking at without admitting I have no idea where the cowl drains to.

 

[louu]

It could be your windshield gasket. That's where mine was just leaking. Have somone spray it with the hose and sit inside and watch for it.

 

[Scott Delaney]

Okay, in daylight this morning I got a good look in that access hole and also snaked my camera in there. It's clean, no rust or anything.

So I sprayed the driver's side of the windshield with the hose for 5 minutes to no avail. No water in the driver's side floor at all. However, I did learn where the cowl drains between the door and the front wheel. It's totally clear and drains VERY fast.

One thing I did notice is that there is an 1.5 inch gap in the door seal at the bottom near the front. Is it possible that the rain runs down the seal to the bottom and is then drawn into the floor by capillary action? Is that gap normal or should the two ends if the door seal meet?

 

[Raider L]

@Scott Delaney,

I installed all new door seals on my truck. The ends should come together at the bottom middle. But over time the seals shrink and a gap will form but not no 1 1/2"! Somebody must have done those seals and didn't cut it off right and left that gap and didn't care. But unless your truck has gone through water above the bottom of the doors, water will not run inside the cab. The floor is slanted slightly towards the door right there so it won't run inside. I have a similar leak on the passenger side and I have no idea where it comes from. The middle of the carpet will be damp every once in a great while.
And as you saw, the rain water falls into the cavity where the wiper motor is, then falls down the nose of the truck and goes into the the drain hole in the bottom of the fender and out. Your hood seal will keep any rain out of that hole you showed in the first pics. Unless you have a hole somewhere along the base of the windshield, or down along the nose of the cab behind the fender on the drivers side...??
Take the front fender off and take a look. They are easy to get back on, it's just time consuming taking all the bolts out. When you go back on leave all the bolts loose so you can shift it around and when all the bolts are lined up tighten it up. Besides when you get the fender off you can dump out all the leaves and dirt that has built up over the years down in the bottom of the rear of the fender.

 

[Raider L]

@Scott Delaney,

On second look at that first pic of the valance it looks like the hood seal doesn't seal over that hole. I seals in front of it. You have an '80's truck. I got my years mixed up.

 

[SirRobyn0]

One thing I did notice is that there is an 1.5 inch gap in the door seal at the bottom near the front. Is it possible that the rain runs down the seal to the bottom and is then drawn into the floor by capillary action? Is that gap normal or should the two ends if the door seal meet?

It's possible. It's also possible for water to come past the door seal up higher if the seals are original or older and have flattened out a lot.
It's also possible to have cowling leak into the cab that isn't rusty. It's far more common if rust is present, but it's possible for the sealant at the cowl seem to dry crack and leak. Water leaks are pain to track down in my opinion, but it's got to be done.

A friend of mine is a glass guy and taught me this trick. It works way better than spraying a hose at the windshield and hoping to see a leak. This is going to take two people, or at least two people make it a lot easier. If you have sprayway glass cleaner on hand you can use that, or mix up a spray bottle off soapy water that will bubble when you shake it. (Windex is not foamy enough, nor is most washer fluid) spray all around the outside of the glass seal. Use your air nozzle, and hold it about 6 inches from the seal and slowly spray air all around the seal. When you get to the spot it leaks at your friend on the outside will see the bubbles. You can do this on the door seals as well, but it is possible to get a false positive on door seals because sometimes those can leak air but not water. Just be careful not to get the air to close to the seal as if you applied it directly to the seal your could blow it out.

Also take some silicone spray. holding it just a few inches from your door seal apply it all around the seal liberally. Have a rag handy to wipe up over spray but let it stand heavy on the rubber seals. After a few minutes the seal will have absorbed the silicone and it'll look like it is starting to come back into the round shape it should be. Give it several applications, letting it soak in for a few minutes between coats. Not only will it help the door seal up better, the seals will look much nicer and newer afterwards. Don't try to use silicone grease it's got to be thin spray on stuff so it'll soak in. As far as I can tell this does no damage to the seals long term and I treat all my car door seals like this regularly.

 

[Rusty Nail]

capillary action

 

[Joshua Keith]

Another spot water can get in is in the passenger kick panel. There is a vent there to let fresh air in and I have seen it’s gasket or even the door flap shrink and let water in. The space on the other side of the flap is the same void where the water drains from your cowling area. Only way to check it is by removing kick panel. Another spot to check while you’re in the area is the firewall on the far right side next to the passenger kick panel. This part of the firewall is home to the a/c evaporator and water sits inside when the water melts off of it. This can cause rust bubbles and eventually holes where the Ac condensation leaks inside. The main culprit is normally the cowling seam seal tho. It cracks and lets water get in between the 2 pieces of sheet metal.

 

[DanMcG]

If you have sprayway glass cleaner on hand you can use that, or mix up a spray bottle off soapy water that will bubble when you shake it. (Windex is not foamy enough, nor is most washer fluid) spray all around the outside of the glass seal. Use your air nozzle, and hold it about 6 inches from the seal and slowly spray air all around the seal. When you get to the spot it leaks at your friend on the outside will see the bubbles.

Thanks Rob, this worked like a charm. The upper and lower corners on the passenger side were blowing some fine looking bubbles. I'll be caulking them in temporarily till I start stripping the cab for paint.

 

[SirRobyn0]

Thanks Rob, this worked like a charm. The upper and lower corners on the passenger side were blowing some fine looking bubbles. I'll be caulking them in temporarily till I start stripping the cab for paint.

Your welcome, a friend of mine is a glass guy and taught me that trick. Glad it worked!

 

[DanMcG]

I thought I'd follow up on this thread. As I mentioned above my windshield gasket was leaking and I temporarily fixed it but I'd still find some water on the floor from time to time.
I finally figured out that the door to cab seal was so flattened out that the water was running down the door gap and onto the floor. I replaced the seal and has been dry ever since.

 

[Ken B]

So to summarize....watch for windshield gasket ,door seal, firewall, and vent flapper.
gotta get those in my head as i work on this cab.