IO-390-D Series Engine Maintenance Manual
72-25
© 2020 Avco Corporation. All Rights Reserved
Page 186
March 2020
IO-390-D Series Engine Maintenance Manual
2.
Oil Pump Removal
A.
Remove the safety wire (Figure 3) from the slotted nuts that attach the oil pump body to the
accessory housing.
Figure 3
Oil Pump
Figure 4
Oil Pump and Internal Side of the Accessory Housing
B.
Remove the three slotted nuts and three washers that attach the oil pump body to the
accessory housing.
C.
Remove the oil pump body.
D.
Remove the oil pump drive shaft from impeller B (Figure 4) on the oil pump.
E.
Remove the impellers A and B from the oil pump
3.
Oil Pump Installation
A.
Lubricate all parts of the oil pump, the tachometer shaft, and other contact surfaces such as
gear teeth and idler hubs with a mixture of 15% pre-lubricant and 85% SAE No. 50 mineral
base aviation grade lubricating oil.
B.
Install impellers A and B in their respective compartments in the oil pump body (Figure 4).
C.
Install the oil pump drive shaft into the oil pump body and through impeller B (Figure 4).
D.
Install the oil pump over the mounting studs on the accessory housing.
E.
Install a washer and new slotted nut on each of the three studs on the accessory housing.
F.
While turning the oil pump drive shaft to ensure free movement of the impellers, torque the
three slotted nuts gradually and evenly to 17 ft.-lb. (23 Nm),
NOTICE:
If the oil pump drive gear assembly binds while tightening the slotted nuts, remove
the oil pump, examine all parts of the oil pump for wear or damage. Replace worn or
damaged parts if necessary and re-install the oil pump.
G.
Safety wire the three slotted nuts as shown in Figure 3.
