Cowl Ventilator Drain Tube

[plymouthasc]

Does anyone have an original cowl ventilator tube (#793597) or grommet (#834696)?

I am trying to figure out the size of the original tube (I.D. and O.D). It takes a 3/8" I.D. tube to attach to the drain spout, but I am not sure of the outside diameter where it goes through the firewall. Heater hose is 3/4" O.D. and fuel hose is 5/8" O.D. of course the grommet would need to fit the size of the hose.

Someone suggested the end of the hose where it attaches to the cowl vent drain may have been flaired like a dishwasher drain hose to accommodate the 3/8" I.D. requirement but then reduced to a 1/4" I.D. hose with a 1/2" O.D. where it passes through the firewall. Once again this would neccessitate a different size grommet.

Any information would be helpful. I have someone who is willing to reproduce the parts if I can figure out how they were made originally. If you know of correct reproductions already, I am interested in the source.

Also, how long was the hose? How far did it hang down the firewall past the clip? Where did it actually drain to the ground?

Thanks for the information.

Mark

[greg g]

this is on a 46, as far as I know it has never been molested Perhaps you can get the size by comparing it to the other gromet that the choke cable comes through.

Mine goes to a sheetmetal clip on the firewall and the tube hangs down about 1 inch or so from where the toe board starts to slant back. Come to think of it, I may have cut an inch or so off an end to expose a fresh uncracked portion to the vent outlet, so the fire wall end might could be an inch or two longer than currently is.

[Desotodav]

Mark, the cowl vent hoses that I have seen on a few trucks now seem to protrude from the firewall only a few inches. I don't imagine that they would be too different from the car ones. I used rubber fuel line for my cowl vent overflow - it was a tight fit with pre-heating with hot water required to get it on. I extended the length down so that I could end it with a metal holding clip mounted off the hand-brake bracket as I thought that it looked neater that way. The hose size would obviously depend on the grommet that you used. I measured the hole size in my firewall with my digital vernier caliper and it showed 0.963".

Desotodav

[Mark D]

Uncanny how timely some of these questions can be. I also noticed the cowl vent tube on my car was brittle and in need of replacement. Now i have the answer to carry to the local napa store!

[plymouthasc]

Thanks for the information. I think I will use the 3/8" fuel hose with 5/8" OD. That is readily available and seems like it would not be too heavy.

Mark