I have an issue with my Cessna 182G. My issue is my plane always uses fuel from the right tank and I just did a longer flight than normal. On this flight the plane only used fuel from the right side and I switched to left tank to balance the burn. After 20 min the plane started to run rough like it was running out of fuel. I switched the fuel selector to both and smoothed out. The right fuel tank ran out pretty fast and I diverted to the nearest airport. I had 7 gallons left in the right tank and the left was almost full. On the way home I switched the fuel caps and the right tank still drained fast. I switched to the left and then flew for about an hour with no problems. I switched back to both and the left tank started filling and the right side went down very fast. Do you think this is can be caused by the vent pipe not being behind the wing strut? I'm looking for any ideas so I can start chipping away at the possibilities.

That sounds more like a plugged fuel vent than anything else.

Sounds like an experience I had years ago with a Cardinal. Mud Daubers packed one of the fuel vents solid. Easy to miss if you didnt look straight on at it. Cleared with a piece of wire.

It's been a long time since I flew a 182 but I used to fly one in a flying club and I found if the vent wasn't behind the strut, weird things would happen such as venting, porting fuel out and uneven burn between tanks. Check this out first; bend it.

My vent tube is over an inch below the strut. I don't know if I can bend it that much. I will look at it tomorrow. I will also check for the plugged vent. This plane only has one vent on the left side. One more thing to add is that I just bought this plane 2 months ago and it still has the flush mount fuel caps.

Check the service manual. It shows exactly where the vent(s) should be positioned.

I have been kinda looking for a service manual for this but everything I find is later models. I will spend a little more time tonight and really look for one.

You need to find a schematic for your fuel system. I am guessing but I would think each tank is vented and that there is also a crossover tube between the tanks. Early Cessna 120's did not include the crossover but they also did not have a "both" position on the selector.

If it were me I would have your mechanic disconnect the fuel line and measure the flow from the left, right and both positions with the fuel caps on and off.

Robert

from looking at theplane earlier both tanks are vented through the caps but there is only one vent below the wing. it is on the left wing. there is a tube between the two tanks. the selector valve has left, right, and both.

The vent must be directly behind the strut. When it isn't the air pressure is forcing fuel from the left tank into the right tank. You don't necessarily bend the vent but rather slide it up and down.

John,

Cessna has made both the parts manual and the service manual available for download.
Position of the external vent by the strut is crucial, the directions call out measurement to the 1/8 inch. I have a PDF somewhere of them, pm me an email and I will send that along.

Ras

Service Manual for 1963-1968:

http://www.redskyventures.org/doc/cessn ... 7-1-13.pdf

Re: your flush caps ... I intentionally kept mine rather than install Monarch's. Why? Some Monarch cap installations have a habit of venting fuel overboard during flight. I choose to maintain my flush (Shaw) caps. Every couple of years I replace all the O-rings ... I prefer flourosilicone over rubber compounds,

Keep in mind that the fuel door (what Cessna calls the plate the flush cap mates to) can develop porosity over time. It'll look shiny, but put a light behind it, and it shines through. Water also moves through those tiny holes, before it ever gets to you o-rings.

Paul

The vent must be directly behind the strut. When it isn't the air pressure is forcing fuel from the left tank into the right tank. You don't necessarily bend the vent but rather slide it up and down.

I will adjust the height of the vent tube today. The one thing that is bothering me is the right tank is the one that is being used. the left tank is not. Everything I have read is the left tank draining fast. My vent tube is on the left wing in direct path of airflow. I would think that would create pressure and cause right tank to fill.