Njacko wrote:

Mountain Doctor wrote:I seem to remember that the transfer pumps pump one and a half gallons per minute per side. If I recall correctly, the information is buried in the pilot operators handbook somewhere.

It should be under "Normal Flight Operations", part G. My AFM says 0.4 gallons per minute, which equals 1.5 litres/min, but your Maule may vary. My left hand aux pump seems a bit faster than the right hand one...

ATB, Peter.

Thanks for double checking.

Incidentally, the aux pumps sound like diaphragm pumps. Unlike some impeller- or vane-type pumps they shouldn't be at all reliant on the fluid which they are pumping for lubrication or cooling.

It must be good practice to turn them off after use, but if there were any great harm in not doing so the Feds would surely have inflicted another f-f-fine placard on us to that effect...

Kip Wilkes at Maule says the pumps cannot be damaged by running them dry and they transfer at .4 gpm each.

They are diaphragm pumps