Have a R182 with long range 88 gal usable tanks with Monarch caps. I am unable to top the tanks to full and filling to the bottom of the Monarch flange is about 37.5 gallons a side vs 44.

Anyone else with this issue and a solution other that replacing the caps with Cessna.

It can't always be done, but placing the fuel nozzle deep into the tank so that it is filling up to the filler neck, not trying to fuel down thru the filler neck helps. It is harder if you are using a hose that has "auto-shut off" when it is placed down into the fuel.

If you can’t get full fuel into the tanks, How / Why did the FAA approve an STC that reduces the aircraft fuel capacity without a POH amendment? Or is the issue the vent valve not allowing the pressure out?

What’s the point of the monarch cap again, wasn’t it like better to keep rain out or something?

Never had a issue with any of my factory caps

Get a funnel. No issues

ZBDRACE wrote:Get a funnel. No issues

Have you tried this and it worked?

Funnel works but you won’t know how full it is until you’re spilling gas.

The older original Gold cap monarch setup is nice. The new ones were nothing but trouble for me. I don’t recommend them to anyone.

I don't understand the reason for not being able to fill the tanks all the way - what is stopping it. I don't see how a filler neck is going to stop you from filling the tank - are you saying that the level of the fuel is higher in the filler neck then level of the fuel in the surrounding void of the tank? Is the top of the filler neck physically lower than the top of your tank?