Demister? What is it?

[tonytrakovich]

What exactly is a demister? I have 1989 DD 12V92TA with Walker Air Seps. There is a demister warning panel at the helm that is all corroded. So I figured I would try to find out what it is. I have done a little reading on HOF and am still not clear if I have one. What does it look like? Where are they located? I do not have a crap can, whatever that is.

 

[captddis]

What exactly is a demister? I have 1989 DD 12V92TA with Walker Air Seps. There is a demister warning panel at the helm that is all corroded. So I figured I would try to find out what it is. I have done a little reading on HOF and am still not clear if I have one. What does it look like? Where are they located? I do not have a crap can, whatever that is.

The demisters were popular before Airseps became along. They basically seperated the the mist from the air filters and sent them to a can with a filter. you could also route the air box puke into it.
Racor / Parker bought the demisters and kind of support them.
I still use my demisters to hold the air box puke and drain then yearly.

 

[tonytrakovich]

If I don't have demisters then where does my air box puke go?

 

[johnjen50]

You should see a small tube going down the side into the oil pan.

 

[captddis]

If I don't have demisters then where does my air box puke go?

I assume you have Airseps. the puke probably goes back into the oil pan, or you may still have the demister.

 

[Nonchalant1]

Detroit Diesel recommends that Airbox and AirSep drains now should be routed to a "crap can" instead of returning the dirty oil to the oil pan of the engine. AirSep makes a "crap can" exactly for this purpose. I rerouted my drains to these and put a small threaded brass pipe plug in the original drain tube holes.

 

[DCMY #92]

If I don't have demisters then where does my air box puke go?

My air box drains dump to atmosphere (bilge or crap can), not to the oil pan. I think oil due to crankcase blow-by can be returned to the oil pan via a demister or AirSep. It's interested that a previous reply says DDC no longer recommends this.

My 53 year old 6V52 naturals have no demister. They discharge the crankcase blow-by into the air inlet, where it ends up coming out the air box drains. I'm was considering installing demisters to save some oil consumption, but if I can't send it to the oil pan there is no point.