What is the purpose of the cowl vent?

[bigoilman]

Seems like a stupid question but other than a place to collect leaves and start rust, what does it do?

[D13]

Assuming you are talking the screen covered area just in front of the windshield, that is the air intake for the heater / AC /vents. It is protected from engine fumes by a seal along the hood, is big enough so rain settles out instead of going though the blower, and is a good place to hide washer hoses etc.

[bigoilman]

That's exactly the info I was looking for.

[andrewmp6]

On really early cars it was just a way to get fresh air in so you have a breeze,This was long before having heat or ac.Later it got used for fresh air for the heat and air like said,If you go with a vintage air unit those reuse the inside air so you could shave the cowl aka weld it shut.

[minitrail]

I am still surprised this was the best setup that could be engineered in 1970s. Lets see....well we need to get some air into the car what should we do? Maybe we can open up a large section of the car facing up to the heavens for air to get into, great problem solved. But wait...what do we do with the water and everything else that happens to fall in there?. No problem, what we will do is route all of that water, into the cab, through the fresh air vent. But what if debris collects somewhere in the process? That could leave pooling water in the cowl or worse yet send water into the cab?....ahhh, we will be long retired when they figure that out.

[andrewmp6]

Only other system i seen was the 57 chevy cars had a fresh air system they sucked air in around the headlights then piped it back across the inter fenders in to the fire wall.You had pull cables to open each side and it blew air under the dash.If the car had a heater it used the same fresh air also.

[bigoilman]

Thanks. I have Vintage Air in my 1936 Chevy so I'm familiar with that type of cowl vent. On theses trucks it just seems like a poor design. As I understand it, the A/C on "max" recirculates air instead of taking in new air. Previous owner of my truck said the area was covered by sheetmetal by the original owner. Presumably because of a leak. The guy I bought it from couldn't make it leak (he tried), removed the homemade cover and installed a new stock grating. He may have fixed the presumed leak with the new windshield and seals before trying to find a leak. Just wanted to know if it needs to be open for normal operation of HVAC system.

[TrailerTrash]

Originally Posted by andrewmp6

If you go with a vintage air unit those reuse the inside air so you could shave the cowl aka weld it shut.

I wouldnt do that unless you are 100% confident that the wiper system will never give you trouble

[K10-Kansas]

Do the mesh aftermarket screens fix the leaf issue?

[Dead Parrot]

Originally Posted by K10-Kansas

Do the mesh aftermarket screens fix the leaf issue?

Unless it is a very fine mesh, expect some leaves. The mesh helps but things like grass clippings and willow leaves can get it. Plus small bugs that crawl in and then expire.