Draining the oilYesterday morning I did a short flight to warm the oil, then drained the oil and changed the oil filter. While the oil was out, I attacked the leaky oil quick drain valve. I had installed a cheap quick drain valve many years ago, but noticed that it was leaking earlier this year. The Curtiss drain valve I had installed was not rebuildable, so I bought a more expensive Saf-Air P5000 drain valve.


Quick drain valve, with tangs removedRemoving the old oil drain valve was a much bigger job than I had expected. I had to remove a heat muff and detach an intake tube so I could have enough clearance to get a wrench on the valve. But, I couldn’t get it to turn before the open end wrench started to flex and threaten to round off the hex flats. Drat.

I couldn’t use a box wrench or a socket as the valve had two tangs sticking out. I had to cut off the tangs and file down the ends so I could get a long reach six point socket on it. That allowed me to get enough torque on it to unscrew it.