Figure 3-9: Hydraulic Manifold - Snorkel TM12 Service And Parts Manual

Section 3 - Service & Repair
M R
AIN ELIEF
1. Operate the hydraulic system 10 to 15 minutes to
warm the oil.
2. Remove the cap or loosen the locknut on the Main
Relief Valve.
3. Install a 0-207 bar (0-3000 psi) pressure gauge to
the gauge port.
4. Turn the Chassis Keyswitch to CHASSIS and ele-
vate the machine fully.
5. While holding the Chassis Lift Switch to the UP
position, adjust the Main Relief Valve until the
pressure gauge reads 165 bar (2400 psi).
6. Release the Chassis Lift Switch.
7. Replace the cap, or tighten the locknut on the Lift
Relief Valve, and torque to 8N-m (6 ft-lbs).
8. Lower the platform.
C
OUNTERBALANCE
1. Operate the work platform for 10-15 minutes to bring the hydraulic oil up to normal operating tempera-
ture.
2. Remove the gauge port cap and install the pressure gauge assembly.
3. Lift work platform and block front wheels off ground.
4. Loosen the locknuts on Counterbalance Valves.
5. With the machine fully powered up depress the DRIVE button on the upper control box, depress the
interlock lever and slowly pull the control lever to REVERSE to drive the wheels.
6. Adjust the Forward Counterbalance Valve by turning the adjustment screw until the pressure gauge indi-
cates 83 bar (1200 psi).
7. Slowly push the Control Lever to FORWARD to drive the wheels.
8. Adjust the Reverse Counterbalance Valve by turning the adjustment screw until the pressure gauge indi-
cates 83 bar (1200 psi).
9. Check the settings by slowly moving the Control Lever FORWARD, then REVERSE, checking the gauge
to ensure pressures are properly set. Re-adjust as needed.
10. Tighten locknuts on valves to 8N-m (6 ft-lbs). Remove blocks and lower work platform to ground.
11. Reconnect the red Control Cable wire to terminal #9.
12. Remove the gauge from the gauge port and re-install cap.
13. Check for proper operation of the drive system and brake.
S
TEERING
1. Operate the work platform for 10-15 minutes to bring the hydraulic oil up to normal operating tempera-
ture.
2. Install gauge in the gauge port.
3. Loosen locknut or remove cover on the Steering Relief Valve and turn adjusting screw counter-clockwise
two full turns.
4. While one person holds the Steering Switch to steer right or left, slowly turn the Steering Relief Valve
adjusting screw clockwise to increase the pressure until the gauge reads 69 bar (1000 psi).
5. Tighten locknut or replace Steering Relief Valve cover and torque to 8N-m (6 ft-lbs).
6. Remove gauge and replace cap.
V
ALVE
V
ALVES
R V
ELIEF ALVES
CHECK VALVE (POTHOLE)
CROSS LINE RELIEF
VALVES (DRIVE)
Hydraulics

Figure 3-9: Hydraulic Manifold

MAIN RELIEF VALVE
RELIEF VALVE
(STEERING)
FLOW RESTRICTOR
PRESSURE RELIEF
(STEERING)
(MAIN LIFT)
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