SkyTrak 6036 Service Manual - Manual (Page 222)

Section 9 Hydraulic System
9-72 Model 6036/6036T S/N 9B0500 thru 14833
Assembly
1. Insert spool in the linkage end of the section.
IMPORTANT. Take care during insertion to avoid
damaging the valve’s internal lands.
2. Install O-ring (14, Fig. 9.40), wiper (13) and
seal plate (15) and secure with two round
head machine screws (16).
3. Install O-ring (14), wiper (13), seal plate (15)
spring seat (11), spring (12), spring seat (11),
spool end (10), spool cap (9) and secure with
socket head capscrews (8).
e. Main Control Valve Installation
1. Position the main control valve (1, Fig. 9.38)
on the forklift and secure it to frame using
capscrews (5), locknuts (7), and washers (6).
2. Install control linkage (4) using retaining pins
(3) and cotter pins (2).
3. Connect hydraulic lines to control valve.
4. Install boom raise/lower section (3) over tie rods
(19 and 20).
5. Install check valve poppet (6) and check valve
spring (7) into boom raise/lower section (3).
6. Install new O-ring (5) in boom extend/retract
section (4).
7. Install boom extend/retract section (4) over tie
rods (19 and 20).
8. Install check valve poppet (6) and check valve
spring (7) into boom extend/retract section (4).
9. Install O-ring (5) in outlet section.
10. Install outlet section (2) over tie rods (19 and
20).
11. Install nuts (21 and 22) on the ends of the tie
rods (19 and 20) and tighten the nuts so the rods
protrude the same amount from both sides of the
valve. Torque nuts (21) to 48 ± 4.8 lb-ft ) 65 ±
6,5 Nm). Torque nuts (22) to 75 ± 7.5 lb-ft (102
± 10 Nm).
d. Repair of Main Control Valve Sections
When repairing the main control valve, first refer to
paragraph b and repair the relief valves. It might be
advisable to install seal and spring (repair) kits in all
of the relief valves at this time, refer to 6036 Parts
Manual for kits.
Disassembly
1. Remove two socket head capscrews (8, Fig.
9.40) and spool cap (9).
2. Remove spool end (10), spring seat (11), spring
(12), spring seat (11), seal plate (15), wiper (13)
and O-ring (14).
3. Remove two round head machine screws (16),
seal plate (15), wiper (13), and O-ring (14).
4. Remove spool from linkage end of valve section.
Cleaning and Drying
Clean all metal parts in an approved solvent such as
trichlorethylene and blow dry.
Inspection and Replacement
1. Inspect spool seating surfaces. They must be
sharp, clean, and free of nicks or excessive
wear. Replace entire section if worn or dam-
aged.
2. Replace all O-rings and backup rings with new
ones. Repair kits are available, refer to 6036
Parts Manual for kits.
3. Make sure the piston moves freely in valve
section.
4. Start the forklift engine.
5. Inspect connections at the control valve for
leakage.
6. Operate joysticks to test the operation of the
control valve and hydraulic system. Refer to
paragraph 9.2 for instructions on adjustment of
relief valve settings.
7. Install the transmission cover.
Before starting the engine be sure all hydraulic
connections are tight and all tools are removed
from the forklift.
Warning
9.6.2 Main Control Valve Assembly
Electronic Control
The control valve has four sections – inlet, outlet
and two working sections, one for raise/lower and
one for extend/retract. The working sections are
mounted between the inlet and outlet sections to
form a valve stack, Fig. 9.41. The supply pressure
passages are common in the stack as are the
return to reservoir and pilot pressure passages.
For a description of how each component oper-
ates in a specific circuit, refer to paragraph 9.3.
For a description of electronic operation, refer to
Section 10.