If you have a homebuilt aircraft, consider this:

Pull the plugs from the engine. Put your ear on the pump. Have someone
slowly turn the prop. Listen to the vanes inside the pump fall from
the inside to the outside of the rotor slot. There should be a regular
"click" as each or the six, ( I think that there are six) vanes fall.

If you do not hear the vanes fall, they most likely are "hung up" due
to some contamination. Open the pump, and clean everything. Put it
back together. I use a little silicon seal to act as a gasket on the
back joint of the pump.
I think that the pumps fail when the vane gets sticky and refuses to
slide in and out of the slot in the rotor. I know that the slots in
the rotor will wear larger eventually, but I listen to my pump every
25 hours at the oil change and have had to clean the pump twice in the
last 250 hours. The pump now has about 800 hours on it.

Good luck.










On 21 Sep 2005 14:03:08 -0700, "nrp" wrote:

How about a slinger followed by a felt seal? The slinger can be made
from an o-ring. Felt will catch any tramp oil, is cheap, & can run dry.


Zenith CH-300 Driver.