L08031 Hoist Circuit Component Repair L8-9
Cleaning and Inspection
1. Clean all parts including housings in solvent and
blow dry with compressed air.
2. Inspect seal counter bores, they must be free of
nicks or grooves.
3. Examine springs for breaks or distortion.
4. Inspect spool (14, Figure 8-12). The spool must
be free of longitudinal score marks, nicks or
grooves.
5. Test spool (14) in spool housing for fit. Spool
must fit freely, without binding, through a com-
plete revolution.
NOTE: The spool housing (17), spool (14), inlet
housing (18) and outlet housing (7) are not serviced
separately. Should any of these parts require
replacement, the entire control valve must be
replaced.
Assembly
1. Thoroughly coat all parts including housing
bores with clean type C-4 hydraulic oil.
2. If the inlet and outlet housings were removed fol-
low steps 3 through 5 for reassembly.
3. Install check poppet (2, Figure 8-14) and spring
(3) in spool housing (1).
4. Install new O-ring (4) in spool housing. Move the
inlet and outlet housings into position.
5. Install tie rods. Install tie rod nuts. Tighten tie rod
nuts to the torques shown in Figure 8-15.
6. Install a new O-ring (27, Figure 8-12) and wiper
(26). Install seal retainer (25).
7. Install spacer (5), spring seats (19), and spring
(4). Thread detent pin (3) into spool (14). Slight
pressure will be required to compress the
detent spring. Tighten detent pin 84-96 in. lbs.
(9-11 N.m) torque. Install spring (20). Carefully
install spool into spool housing.
8. Apply grease to the cross holes of the detent pin
(3) to hold balls (21) and (2).
9. Slide detent sleeve (22) into cap (24) and place
over a punch. Using this punch, depress ball
(21) and insert balls (2) in detent pin cross
holes.
10. While holding down on ball (21), slide detent
sleeve (22) and cap (24) as an assembly over
the detent pin (3). Continue to insert detent
sleeve (22) until it contacts spring seat (19).
11. Secure cap (24) in place with capscrews (6).
Tighten capscrews (6) to 5 ft. lbs. (7 N.m)
torque. Install spacer (23) and snap ring (1).
12. Install a new O-ring (12) and wiper (13). Install
seal plate (16). Install machine screws (15).
13. Using new O-rings, install relief valve (2, Figure
8-13) in spool housing.
1. Spool Housing
2. Check Poppet
3. Spring
4. O-ring
5. Outlet Housing
FIGURE 8-14. HOIST PILOT VALVE ASSEMBLY
1. Nut
2. Tie Rod
3. Nut
4. Tie Rod
5. Outlet Housing
FIGURE 8-15. TIE ROD NUT TORQUE
To Next Page
Loading...
