That’s unusual, normally it’s the diaphrphram leaking that kills pumps.
I forgot to add: the pump was actually changed largely because I was getting 1.5% fuel in the oil, on the last oil analysis. Normally it is around 0 to 0.5%.
I didn’t really believe it was the cause of the funny noise, after changing the mag fixed that.
24 hours before I was set to depart from Kalispell, Montana, to Toulouse, France, the owner of the shop doing my annual insisted that we pulled both fuel pumps. One was 100 hours old, the other one, well, maybe 900 hours old. The 100 hours old pump could be turned by hand – the other one was making the sound of a coffee grounding machine. Needless to says, it now lives a new life as an overhauled unit in some airplane – I got a trade-in overhauled unit instead.
The other difference was that the operating lever on the “bad” pump had almost no downward movement on it. A normal fuel pump of this type has about 5mm of movement, during which you can feel the internal mechanism.
I am surprised the engine ran ok… I guess the available force from the cam is more than adequate.
This pump was changed again recently. This time it was a suspected fault in the diaphragm.
