Purpose if the cowl vent

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Jun 8, 2012
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Southwest Oregon
What purpose does a cowl vent serve? On my 74, it doesn't open,but it does have the two drain holes that are supposed to drain thru the cab and out the hump,but my hump has no holes in it either.
 
The cowl vent on a '74 is only for collecting water and rusting. The drain holes require two expensive bits of hose to drain out out through the firewall.
 
it was functional in earlier years. they just eliminated the function end of it, but never designed it out.



Until 1978, when it was removed completely.


:beer:
 
it was functional in earlier years. they just eliminated the function end of it, but never designed it out.

It also functioned in 74 as well as years later in markets where a heater wasn't standard. In 74 the heater designed changed and had a vent on top that allowed fresh air into the cab using the blower. Markets with no heater the vent still worked. After a couple of years Toyota made cowls with a vent or no vent. So the welded close vent went away.
 
Ok,can I get away with running hose from the drains out thru my firewall,and down?

yes

purpose of the vent if functional ? to let air in :doh:
 
Ok,well doh! Its not functional, so I guess I drain it thru the firewall, thanks.

That is funny, if you don't READ the post then you get an answer like DSTRDR :doh:
The other problem is for the years it DID work the seal is shot and so you have water coming into the cab anyway because they don't make the seal anymore. So you have to get inventive and make one ;)
 
I heard (have not tried it) that you can use pieces of bicycle inner tube to replace the crumbled, formed hoses the run out through the firewall.

Here in AZ, it rarely seems to be an issue.

Rocky
 
I went to home depot and got some drain tubes similar to the old ones. I think they are for aquariums. They had to be bent a bit in order to fit, but they do the job. On my 70 the cowl is still functional, after I dug out 3 inches of dirt and mud in it!:rolleyes:

My transmission cover doesn't have drain holes either, but there was an appropriate sized hole in the firewall that I exited both tubes out of. It works fine for draining, although I don't get a ton of testing in San Diego.

I actually really prefer the cowl vent for function. It helps to blow cool air on my transmission hump which is the hottest part of the truck when driving. I don't have a heater yet, so that plus the bug catchers is my AC. Works well enough for me.
 
Drivers side drain tube is the worst to reproduce. It comes immediately off the cowl vent does an S curve goes right out the firewall through a 3/4" hole I would guess. the passenger drain comes off the cowl and drops several inches before going out an identical sized hole around/above the heater hoses. At least that is how my 73 is. For the passenger side we used heater hose, probably 1/2" as I recall and made the S curve out of two copper elbows soldered together in an S. Hooked up ne hose to them. For the drivers I salvaged the S curve part fo the hose, then spliced on new hose with a chunk of 1/2" copper pipe so the hose would run down the clips on the firewall and drain down low like stock. To make the S curve out of copper for the driver side was going to be very tight. I guess when that last bit of hose rots out, I'll have to try and cram a tiny peice of hose between the cowl fitting the the copper S curve. The factory hose make a very tight preformed curve through the firewall, straight hose will kink and probably not drain very well. When I did my restoration in the mid 90's they were still available at 50 bucks each, we didn't get them back then.

The drains are designed to catch water right and left within the vent well as well as front to back. The hoses extend down the outside of the firewall to the lower area so you do not get any engine vapor coming up into the vent.

Hose is a unique thinwalled stuff, but searching through the preformed heater hoses at the parts store may get you something close that would work.
 
moconative is right- drivers side is a pain- i just stuck a synthetic wine cork in that hole and used the passeneger side only to drain-

works fine!
 
wine cork - now that's a first :hillbilly:

:cheers:
 
I'm thinking jamming a small rubber plug down in there coated with silicon, then packing in some JB weld on top of that,then drain the pass. side thru the firewall.
 
moconative is right- drivers side is a pain- i just stuck a synthetic wine cork in that hole and used the passeneger side only to drain-

works fine!

What do you suggest for those of us who drink wine out of a bottle that has a screw cap?
 
What do you suggest for those of us who drink wine out of a bottle that has a screw cap?

Or out of a cardboard box with a tap? :doh:


My 9/76 doesn't have a cowl vent. Is that true of other pre-'78 rigs?

(Edit: I've actually owned three other '77 model year '40s and none of them had cowl vents either).
 
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