Gear pump cover
Ball check valve
Gear pump housing
cover to housing
Gasket, pump to
4 Cover to housing dowel (2)
Figure 3-57. Clearance check between washer and
Capscrew, cover to housing(2)
Gasket, pump cover
3-8. Gear Pump
Pump gear (2)
a. General. The gear pump draws fuel from the
10 Dowel ring
tank through a filter and supplies the fuel to the fuel
11 Drive shaft
12 Driver shaft
pump. Fuel at a given pressure is then routed to the
Figure 3-58. Gear pump with integral cooling, exploded
Caution: Engines with integral cooling gear
(1) Remove capscrews securing gear cover
(2) Install two long capscrews in cover and
drive against capscrew heads to remove gear cover from
dowels (4) in gear housing. Discard gasket (8).
(3) Lift drive and driven gears and shafts
from gear pump housing.
d. Cleaning and Inspection.
(1) Check pump shafts for wear or scoring;
discard if damaged. Replace shaft if worn smaller the
0.4998/0.5001 inch diameter.
Figure 3-59. Gear width check.
are scored or worn badly, the gears must be replaced
(3) Check gear housing and cover for
scoring or wear; replace as needed. Check gear pocket
(4) Shaft bore in cover and housing should
be 0.5013/0.5016 inch I.D. If gears are removed from
shaft, press gears on shaft 0.680/0.690 inch from
housing end of shaft. Oil shaft before assembly.
(5) Check lubrication holes in cover and
housing they be clean.
(6) Clean cooling kit components, if used,
and dry with compressed air.
Figure 3-60. Gear pocket depth check.