TM 5-3805-274-13&P
0034
DISASSEMBLY
CAUTION
Use two wood blocks between hydraulic pump and jaws of vise.
Failure to comply may result in damage to equipment.
1.
Place hydraulic pump assembly securely in machinist vise, shaft side up.
2.
Remove eight screws (Figure 1, Item 30) and washers (Figure 1, Item 31) from hydraulic pump flange
(Figure 1, Item 4).
3.
Lift hydraulic pump flange (Figure 1, Item 4) off pump body (Figure 1, Item 22), keeping hydraulic
pump flange (Figure 1, Item 4) straight during removal. If flange is stuck, use wooden mallet or plastic
hammer to tap around edge and loosen. It is not necessary to remove two dowel pins (Figure 1, Item 5).
4.
Lay hydraulic pump flange (Figure 1, Item 4) on smooth, clean surface and remove snap ring
(Figure 1, Item 29) and seal press ring (Figure 1, Item 28). Turn hydraulic pump flange
(Figure 1, Item 4) over and tap old seal (Figure 1, Item 27) from bore.
5.
Remove O-ring (Figure 1, Item 6) from hydraulic pump flange (Figure 1, Item 4). Discard
(Figure 1, Item 6).
6.
Remove two back-up rings (Figure 1, Item 8) and O-rings (Figure 1, Item 9). Remove two isolation
plates (Figure 1, Item 12), sealing strips (Figure 1, Item 11), end separators (Figure 1, Item 10), and
center separator (Figure 1, Item 26). Discard back-up rings (Figure 1, Item 8), O-rings (Figure 1, Item 9),
isolation plates (Figure 1, Item 12), sealing strips (Figure 1, Item 11), end separators (Figure 1, Item 10),
and center separator (Figure 1, Item 26).
7.
Mark side of pump body (Figure 1, Item 22) near drive gear (Figure 1, Item 25).
8.
Grasp drive gear extension and lift drive gear (Figure 1, Item 25) slightly with quick, upward motion to
dislodge top pressure plate (Figure 1, Item 13) from inside bore of pump body (Figure 1, Item 22). Using
thumb and forefinger of other hand in slots of top pressure plate (Figure 1, Item 13) and releasing hold
on drive gear (Figure 1, Item 25), lift top pressure plate (Figure 1, Item 13) from pump body
(Figure 1, Item 22).
9.
Lift idler gear (Figure 1, Item 14) and drive gear (Figure 1, Item 25) straight up from pump body
(Figure 1, Item 22).
10.
Remove bottom pressure plate (Figure 1, Item 15) from pump body (Figure 1, Item 22) by inserting
offset screwdriver in holes and lifting up.
CAUTION
Use caution during removal of pressure plate. Do not pry or force it
out. Failure to comply may result in damage to equipment.
11. Remove bottom pressure plate (Figure 1, Item 15) using thumb of each hand in holes in bottom.
12. Remove isolation plates (Figure 1, Item 18) sealing strips (Figure 1, Item 17), end separators
(Figure 1, Item 16), center separator (Figure 1, Item 24), back-up ring (Figure 1, Item 20), and O-ring
(Figure 1, Item 19). Discard isolation plates (Figure 1, Item 18), sealing strips (Figure 1, Item 17), end
separators (Figure 1, Item 16), center separator (Figure 1, Item 24), back-up ring (Figure 1, Item 20), and
O-ring (Figure 1, Item 19).
13. If damaged or worn, remove two bearings (Figure 1, Item 21) from pump body (Figure 1, Item 22) and
two bearings (Figure 1, Item 7) from hydraulic pump flange (Figure 1, Item 4).
CAUTION
Never remove balls or plug as service procedure. These items
provide a vent in case of pressure buildup in pump. Failure to
comply may result in damage to equipment.
14. If balls (Figure 1, Items 2, 3, and 23) are blown out, press new balls (Figure 1, Items 2, 3, and 23) in
with new retainers (Figure 1, Item 1).
0034-2
