Cowl Drain cleaning and maintenance

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SlantedMark4

SlantedMark4

'74 Valiant 225 /6
FABO Gold Member
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I was just wondering how to clean clogged cowls on mid 70's A bodies, just like my '74, which has got water on the driver's side floor panel.
I've figured out that the water comes in from the "under dash vent door" thing. I was looking for answers in many threads but haven' t found a good answer yet so I guess this thread could help other people, too, by list everything up about it. If there's a thread like this already please hmu.

These are my questions:
What are all the water drain locations? Differences of the drains from different years/models? Seals location? What needs to be checked?

The only thing I figured out is that the water whats going into the vent door thing is from the cowl panel but it is welded so getting in by hand seems to be a little difficult. I've read about using a water hose or leaf blower but wouldn't that end in a huge mess?
 
SlantedMark4 said:
I was just wondering how to clean clogged cowls on mid 70's A bodies, just like my '74, which has got water on the driver's side floor panel.
I've figured out that the water comes in from the "under dash vent door" thing. I was looking for answers in many threads but haven' t found a good answer yet so I guess this thread could help other people, too, by list everything up about it. If there's a thread like this already please hmu.

These are my questions:
What are all the water drain locations? Differences of the drains from different years/models? Seals location? What needs to be checked?

The only thing I figured out is that the water whats going into the vent door thing is from the cowl panel but it is welded so getting in by hand seems to be a little difficult. I've read about using a water hose or leaf blower but wouldn't that end in a huge mess?
Click to expand...
I will be interested in finding out about this also for my 73 Duster. I have to remove the front end sheet metal anyway, but like you said, it is very difficult to get inside the cowl/vent area. I know the seals for the wiper motor & linkage to wiper arms will leak when they are shot, letting water in the car there, but the vent boxes under the dash, sounds like there is a build-up of debris causing the water to come in through them. You may have to remove the fenders & such to clean out that area really good. Someone here will have the correct answer for us I'm sure. Anyway, Happy Thanksgiving to all that celebrate it.
 
OK my 74 they run down under the fenders on either side of the firewall. The drains in the bottom clog. I use a piece of wire hooked to grab what I can from the bottom while blowing air in through the air box. No real easy CLEAN way to clean them out. Lots of times the area above the vent box where the j hooks mount rust out at the bottom. Not much you can do there but add new metal. Good luck with it.

Permanent cowl cleanouts?
 
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SlantedMark4 said:
a huge mess?
Click to expand...

halifaxhops said:
blowing air
Click to expand...
This is a yes on both quotes above. Using a air hose with a flexable tube to shove in as far as you can does a good job.
Do this in thru the cowl vent, Heat/A/C vents, floor heat vent and the the fresh air doors.
Not sure on the 74 A body but some of the older Mopars have a rubber flap drain on the cowl under the hood.Air hose in there will blow out a bunch of junk that as built up over 50 years. YES again as being a huge mess but you will be happy in the long run.
 
The water drain locations on every late A body (67-76) that I have seen are in the sides of the cowl. Open the doors and look at the sides of the upper cowl and you can see them. There are at least one on each side. The best way to clean them out is to remove the drivers side air vent box so you can reach up into that side and pull the leaves and crap out by hand. When you get as much out as you can get a hold of, use a shop vac with some type of smaller modified hose taped to the regular hose to vacuum it out. If you aren't afraid to tackle it, take the heater box out and do the same on that side. You can also use an air hose with a blow nozzle on it to herd the debris to where it is easier to get out. Use a small mirror and a drop light or flashlight to look into the cowl. If you're high tech, use a small bore scope that hooks to your cell phone. That's all I've got, so good luck!
 
^^This above^^

These cars were NEVER designed, nor intended to last this long, by "Ma" LOL
 
JDMopar said:
The water drain locations on every late A body (67-76) that I have seen are in the sides of the cowl. Open the doors and look at the sides of the upper cowl and you can see them. There are at least one on each side. The best way to clean them out is to remove the drivers side air vent box so you can reach up into that side and pull the leaves and crap out by hand. When you get as much out as you can get a hold of, use a shop vac with some type of smaller modified hose taped to the regular hose to vacuum it out. If you aren't afraid to tackle it, take the heater box out and do the same on that side. You can also use an air hose with a blow nozzle on it to herd the debris to where it is easier to get out. Use a small mirror and a drop light or flashlight to look into the cowl. If you're high tech, use a small bore scope that hooks to your cell phone. That's all I've got, so good luck!
Click to expand...
I held my phone up in there for photos and videos. All rusted out. Rebuilt with fiberglass and Flexseal (which is amazing!). What fun!
 
The cowl drains are pretty easy to see, you can see both with the hood open. You may have other issues.

20221124_145440.jpg
 
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