Upper ventilation valve position

cabinfever · Post by **cabinfever** » Tue May 17, 2016 1:57 pm

Would the upper ventilation valve control in the photo below be in the "open" or "closed" position? I suppose I could take it off to figure it out myself, but it would save me some time if someone could answer this.

Thanks!

4x4M38 · Post by **4x4M38** » Tue May 17, 2016 2:18 pm

Steve,
Typically a handle in line with a valve is in the open position.
Typically. Not always. The best thing to do is unscrew those
fittings and have a look.

Then you'll know for sure and from now on.

Take care,

cabinfever · Post by **cabinfever** » Tue May 17, 2016 2:31 pm

4x4M38 wrote:Steve,
Typically a handle in line with a valve is in the open position.
Typically. Not always. The best thing to do is unscrew those
fittings and have a look.

Then you'll know for sure and from now on.

Take care,

Good point! I was thinking that little stop tab on the end of the control arm had something to do with it. Like whether it was stopped at the top or the bottom of the valve.

Thanks

4x4M38 · Post by **4x4M38** » Tue May 17, 2016 4:45 pm

That is exactly what it's for, to prevent over travel and
make sure it stops at the correct position.

But time and Bubbas have had a lot to do with the parts
we work on today, and sometimes the slots and holes
in the handles are wallowed out, and the stems rounded
off, which then allows the handles to end up where they
don't belong.

Removal and inspection will also allow you to make sure the
valve bore is unrestricted. It doesn't help to open the valve
if it's full of junk and blocked.

Take care,

Post by **wesk** » Wed May 18, 2016 7:17 am

Just remove the small hose from the nipple at the bottom of the drawing and use an air nozzle to blow into the opening. Then operate the valve and see where the air blows.

cabinfever · Post by **cabinfever** » Wed May 18, 2016 9:48 am

Thanks, Wes and Brian.

I am probably over thinking this, like I usually do. But should the valve be in the open or closed position for general driving (non-fording)? Or, does it even make a difference? My A1 does not have a lower ventilation control valve.

Post by **wesk** » Wed May 18, 2016 10:05 am

Steve,

Look at it this way. For fording you want a closed system that will allow pressurization of the crankcase.

Fording = two closed valves

Daily driving = two open valves.

The system was only installed on early m38A1's thru SN MD 23359 at Willys. The Marines and the Army installed the system as a kit in the field when needed for a specific unit's use. This kit I refer to is not the the other kit with the tubes and clamps for the snorkel & exhaust extension.