Fuel leak - Gascolator?

I have posted on here before about a fuel smell inside the cockpit of my RV12 when flying. I just about stripped the aircraft looking for the leak. Nothing found between the tank and firewall- nothing! I checked the carbs and fuel pipes on the engine side - nothing.

I crawled under the aircraft to clean the underside. I saw a couple of bluegreen stripes (fuel colouring in South Africa) running back along the underside of the aircraft. Looks to be leaking from the Gascolator but not from the nipple or press valve. I cant see where its coming from as on the engine side there is only 1 pipe visible which connects gascolator to the mechanical fuel pump.

From the diagrams I have seen, the gascolator connects on the inside directly through the firewall. I didnt build my aircraft myself so I have no idea what it looks like around there.

Could it be leaking on the entrance connector to the gascolator?

Any thoughts would be very helpful.

Regards


Hans

This is a link to the fuel system chapter: Fuel system chapter 28

You can also have some spillage from the mechanical fuel pump drain hose just right from the gascolator: see page 46-18

The majority of my clients that have had fuel smell in the cockpit has come from either a leaky carb bowl gasket (should be live fuel or residue in the drip tray and on the bottom of the bowl) or fuel puking out a carb vent. If you have black rubber hose lines on the vent leaks can be hard to detect. A quick way to check is yank the vent hose off the carbs and temporarily replace them with a clear poly tube about 4" long on each carb. The hose can just dangle while it's running for a quick look to make sure this isn't the problem area. It seems rare to leak from a hose and could be the gascolator especially if someone has taken it apart lately. Any of these should show some sign of a leak. While flying the high pressure air coming through the cowl not only pushes the smell your way, but blows the fuel off the leak area which can make it hard to find.
I usually check for leaks on the ground while running up around 2500-3000 rpm. It can make finding the leak easier.

Thank you Roger!

I will check as you suggest

Hansgiant said:

..........Could it be leaking on the entrance connector to the gascolator?.........

Click to expand...

It could be, if during construction the fitting was not properly torqued into the gascolator body, or there is a defect or crack. Have you pulled the covers and looked back there for stains?