Halestorm wrote:How can people be having such disparate experiences with these caps?

Both of Kenmore's 180s have Monarch caps, airframes in excess of 15,000 hours, spend all year outside in Seattle (rain!) yet no water in the tanks ever. In my own 182 I can park a full right hand tank downhill with nary a drop spilled. I do keep the o-rings on the caps lubricated with a very light film of DC4.

Granted my example is just as anecdotal (yet perhaps more specific) as both Bdiazair and north river's example are so what's correct in regard to these caps? How can they be this problematic without more uproar from the aviation public? Many hundreds of aircraft are equipped with these caps yet no ADs are out there.

I want to know why you guys are having such poor luck with these things while most of us seem to be having no trouble with them. This is purely selfish, I don't want mine to start leaking!

[quote="Halestorm"]

What he said ^

Some sort of install error happening? Sure don't know what it'd be tho.
Bad production batch?

We've had positive results.... Several sets installed over long periods.

Northriver, my wagon that went up north has 4. Several sets here and bcv.
Should do a cap swap sometime..... to see what's up
......,when we aren't both busy
Hahaha

mountainmatt wrote:This guy has a series of videos with them pouring fuel out.

https://www.youtube.com/channel/UCpBhhk ... jVy96XbvPA

Is this guy missing his o-ring? It looks like the cap is hard against the mount ring, usually they don't quite touch it. Might just be an illusion.


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Halestorm wrote:
Is this guy missing his o-ring? It looks like the cap is hard against the mount ring, usually they don't quite touch it. Might just be an illusion.


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It said he tried adjusting his O-Rings, those two videos were after. Here is a before with fuel pouring out:



Then he posted this:

"This video was taken a few days later. I switched out caps with my buddy and his 185. You will see him in the video. Having a different cap made no difference at all. There is also significantly less fuel in this tank as I had to fly an hour to get to his field, plus whatever leaked out during that hour. My cap did not leak on his airplane. Sort of eliminates the cap as the culprit..."

Definitely doesn't look like mine.

My gasket makes good contact with the plate. Those caps must have been made in China!!!!!

Looks to me that it's not his caps that are leaking, but that his adapter plate isn't mated properly with his fuel bladder. This fits with the data that his buddy experienced no leaks when they switched caps.

Sure hope he doesn't keep flying around for hours with a known fuel leak.

This is a general comment, not necessarily about these leaky caps, but the very best parts can be compromised by faulty installations. Specifically, with so many Monarchs in the field which are successful and so few that aren't, pretty good bet that there are some installation issues on the unsuccessful ones. What those issues might be, I haven't the faintest idea, but it would be nice to know. At some point, if Hartwig and the FAA can quit squabbling about who is delaying it, I'd like to put them on my P172D, but right now, they're only STC'd for 177, 180, 185, 188, 205, 206, and 210. I think I've talked with Butch Hartwig every year for 8 years, and he blames the FAA, but the FAA guy involved blames Butch--and I'm not really interested in mediating their squabble.

Mine are in a well of sorts, which collects water which is supposedly drained off through scuppers, but when I park outside for more than a few hours, I have some Stay Sealed fuel cap covers that I put in place--they don't really "seal" as much as they act like little umbrellas to significantly reduce the amount of water that gets into the well.

Cary

I'll honestly say that my report on these caps is based on what I have seen. I'll just encourage you all to be cautious. Fly safe, make sure you sump your tanks.

hotrod180 wrote:.....I have the early caps with the flap-jack covers and don't mind them,
but the latches on the covers are goofed up and a PITA....

I decided to just replace the goofed up latches on the fuel filler covers, and keep the Monarch caps on the shelf for now-- maybe wait to install them until such time as the bladders need to come out. FWIW the latches are Hartwell p/n 5000-2 "trigger lock" latches. In researching them I discovered that prices are all over the place, but Shortfielder tipped me off that they're available from Wicks Aircraft Supply for about $21 a shot. But I found an even better deal than that-- it turns out that a buddy of mine had a pair, and he was willing to settle for me just buying him lunch at our favorite airport cafe.

http://aircraftproducts.wicksaircraft.c ... ch/h5000-2

The fuel leaking out is annoying, but the real safety issue is shown in this photo.



This is not an isolated experience, all six of the caps I have had installed lately have had this issue to some extent. Water simply pours into the cap. You can see it sitting on the flapper valve sometimes, sometimes it leaks down into the tank. The so called "killer caps" never leaked this bad. In fact, Flint tip tanks and the Britten-Norman Islander both use the same type of cap as the 'killer caps' and no one complains about them. I guess we all have our own experiences.....

If someone could explain how this type of leaking could be caused by installation error I am all ears and will be the first to post that it was a cure!

I've run Monarch caps on a couple of airplanes and never had any issues, no water in tanks, no leakage, just worked over the course of a few thousand hours, and lots of time parked out in the weather.

MTV

North River wrote:The fuel leaking out is annoying, but the real safety issue is shown in this photo.



This is not an isolated experience, all six of the caps I have had installed lately have had this issue to some extent. Water simply pours into the cap. You can see it sitting on the flapper valve sometimes, sometimes it leaks down into the tank. The so called "killer caps" never leaked this bad. In fact, Flint tip tanks and the Britten-Norman Islander both use the same type of cap as the 'killer caps' and no one complains about them. I guess we all have our own experiences.....

If someone could explain how this type of leaking could be caused by installation error I am all ears and will be the first to post that it was a cure!

Holy Cow bro. worse in pics than it sounded!

Hopefully the manufacturer intervenes here. They got something going on.

I'd go with any other option if I saw that repeatedly too. Good luck. B safe.

Might Call Steve about the neck adapters Atlee sells. Or late model tank panels.....

wow.

180Marty wrote:Hotrod, since yours are off would you do something for me? Install the cap and put a big rim glass on the underside of the plate with water and see if it leaks when you turn it upside down. If it does, where?????

Did that today. Held it upside down for about a minute, no leaks detected.
FWIW here's a couple photos--
the first one showing how the cap stands proud of the adapter plate, not down tight against it.
The second showing the profile of the cap seal-- not a standard o-ring, it's kind of a double-vee configuration.
I'd guess that if someone's Monarch cap is down tight against the adapter plate, there's something haywire with the seal.

North River wrote:The fuel leaking out is annoying, but the real safety issue is shown in this photo.



This is not an isolated experience, all six of the caps I have had installed lately have had this issue to some extent. Water simply pours into the cap. You can see it sitting on the flapper valve sometimes, sometimes it leaks down into the tank. The so called "killer caps" never leaked this bad. In fact, Flint tip tanks and the Britten-Norman Islander both use the same type of cap as the 'killer caps' and no one complains about them. I guess we all have our own experiences.....

If someone could explain how this type of leaking could be caused by installation error I am all ears and will be the first to post that it was a cure!

Wow, hard to argue with a picture like that. This is quite the mystery. There must be an answer though, things don't just simply happen. Find an impartial friend to take gander at the situation and keep hounding the manufacturer with photos like these.

When I look at North River's picture I wonder------ do you power wash the top of the wing and especially under the gas cap or do you have an unhappy neighbor that removes the caps, adds water, and then reinstalls?

I have Monarch aux tanks in my 185 with Monarch caps and have had no issues.
My caps are more like conventional caps not the screw on ones.
Not sure when they changed.

Never heard of Monarch caps that look like that.
Does the fuel filler neck have a clapper down inside of it?
Along with the screw-on-til-it-clicks cap, that seems to be the other hallmark of the "Monarch premium cap system".

Kinda makes me wonder if someone modified a stock cap by putting a Monarch "umbrella" top on it.

I don't think they were modified because the Monarch tanks were installed with their caps at the same time before I owned it.
There is no clapper in the tank.

I will go through the aircraft records and see what I can find.

T

hotrod180 wrote:Never heard of Monarch caps that look like that.
Does the fuel filler neck have a clapper down inside of it?
Along with the screw-on-til-it-clicks cap, that seems to be the other hallmark of the "Monarch premium cap system".

Kinda makes me wonder if someone modified a stock cap by putting a Monarch "umbrella" top on it.

His airplane has Monarch TANKS, not Cessna tanks. They replace the entire bladder with a fiberglass tank. Totally different filler assy.

MTV

Interesting that Monarch wouldn't use a "Monarch premium cap system" on their own fuel tanks.