TM 5-3895-371-24 & P
General Instructions (Before Disassembly of Hydraulic Motor).
Parts and work area must be kept absolutely clean at all times. The Dynapower unit
must be cleaned externally with a commercial degreaser or steam and dried before hoses are discon-
nected and before the unit is removed from the application.
Most service operations are carried out with the motor in a shaft down position. A 7 in.
sq. block of wood, 4 in. thick with a 2 in. round center hole may be used as a platform upon which the
motor may be positioned. A similar size hole in a work bench surface may be utilized as can the corru-
gated cardboard spacer packed at the end of a new Dynapower motor.
When performing minor service work, do not remove bearings, dowel pins, or cylinder
block components unless they exhibit signs of galling, scratching, or excessive wear. On major over-
hauls, replace all bearings regardless of condition.
Disassemble Hydraulic Motor. (Refer to fig. 3-58 and 3-60.)
Place hydraulic motor assembly (1) in a shaft down position. Remove plug (61) with
Remove by-pass hose (27, fig. 3-58) from cover (35, fig. 3-60) and housing (28).
Remove tee (29, fig. 3-58) and O-ring (33) from housing (28, fig. 3-80).
Remove elbow (26, fig. 3-58) and O-ring (33) from cover (35, fig. 3-60).
Remove high pressure relief valve plug (59), O-ring (31), spring (58), and high pressure
relief valve plunger (57).
Remove capscrew (53, fig. 3-60), hex nut (55), and spring seat assembly (54) as a unit
to prevent changing of the setting (if pressure valve needs adjusting see para 3-5). Then remove O-ring
(52), inner spring seat (51), O-ring (50), spring (49), valve pilot (48), and seat (47).
Remove low pressure relief valve plug (30), O-ring (31), spring (32), and plunger (33).
(Refer to fig. 3-61.)
Remove two shuttle valve plugs (40), and O-rings (31). Slide shuttle valve assembly (39)
from cover (35). (Refer to fig. 3-62.)
Unless leakage is experienced, do not remove plugs (38, fig. 3-60) or O-rings (37). If
leaking, replace O-rings (37).
If cover (35) is to be removed it is important that the cover-housing relationship be
preserved. Mark both the housing (28) and cover (35) in such a way that upon reassembly, the relation-
ship can be maintained. For example, a scratch in the paint across the cover-housing parting line can be
used. (Refer to fig. 3-63.)