Is there a Mod. to instal backup vent to the old killer caps?

Other than installing monarchs I’m not sure. I’d think long and hard before doing monarchs. Maybe consider installing the Atlee Dodge adapters with vented caps.

https://backcountrypilot.org/forum/mona ... caps-20643

They look like a very good alternative to replace the killer caps, tks.

My Q. is more oriented to know if non vented killer caps can be modified to have backup vent.

"killer caps" have vents. Best fix is install later cessna "umbrella' caps and adapter plates.
Used to be reasonably priced, not so much now.

What do you consider to be 'killer caps'? That was a term invented by the late John Frank to describe the plastic flush caps.

They look like this one.

The cap in that photo looks like a metal cap and it is NOT a killer cap. That cap has two o-rings that are easy to replace. There is a whole thread on BT about improving the o-ring material, as a matter of fact, as Beech guys use the same cap.

The thing is that the one in the pic I posted don't have the backup vent feature.

Maybe they should be called killer killer cap then

So, can it be converted to just killer cap ?

They are on ebay all the time. Could also call Faeth or Wentworth or skywagoncity

https://www.ebay.com/itm/C-156001-0106- ... SwBRlc1c1H

If you really have the old Wisco plastic ones, maybe toss 'em and install the metal ones

I have the metal ones and as long as you keep both seals in good condition they work perfectly well to prevent water from coming in or fuel to leak out but that is not my Q.

Just wonder if they can be drilled to put a backup vent valve just in case the main vent gets blocked for some reason.

If that can not be done think I would rader buy Atlee Dodge adapters and go that way.

[email protected] wrote:I have the metal ones and as long as you keep both seals in good condition they work perfectly well to prevent water from coming in or fuel to leak out but that is not my Q.

Just wonder if they can be drilled to put a backup vent valve just in case the main vent gets blocked for some reason.

If that can not be done think I would rader buy Atlee Dodge adapters and go that way.

I remember 20 years ago there was a company advertising in T-A-P that they could modify unvented caps. No clue if they are still around, but lots of vented Wiscos are on sale either from ebay or salvage yards.

Well, thanks for the picture slow18. I see I have the red plastic "killer caps" on my recently acquired 180K wet wing. The o-ring on the perimeter must be good since I really have to dig to get them off so must be the o-ring where the flip twist deal goes through the center. Have been thinking if I leave it outside, I will either tape plastic over the area or get a toilet bowl plunger and rig a strap to hold it in place to seal water out.

180Marty wrote:.... or get a toilet bowl plunger and rig a strap to hold it in place to seal water out.

Leave the handle on-- that'll make it easier to find your airplane on a crowded ramp.

Yeah, or do the Atlee Dodge kit or install Cessna raised caps. This winter I’m removing my monarch inboard cap systems and replacing with Cessna raised cap setup. I want to say that someone makes a fuel cap rain cover as well.

slow18 wrote:Yeah, or do the Atlee Dodge kit or install Cessna raised caps. This winter I’m removing my monarch inboard cap systems and replacing with Cessna raised cap setup. I want to say that someone makes a fuel cap rain cover as well.

Why introduce more drag?

Follow the link...
I'm pretty sure those covers are just installed while parked.
The "remove before flight" streamer was the give-away.

I was referring to going from flush caps to 'raised' caps