it’s been discussed before…but, I’ve found no success with anything (including wash/n/wax and greased lightning) to remove the stains on my main fairings from a slow leak from the sump…it was not very old (a few days) when I caught it…but nothing touches the stains…any new ideas?
Use some fuel, which you can drain from the sump. It has worked for me on my prior plane when the sump dripped.
Try some hydraulic fluid. It works great on my Cessna. After the stain comes off use a little soap and water to remove the fluid so it does not attract more grime.
Fuel is exactly what my mechanic suggested when I got a whopping stain on the wheel pant. It worked fine.