Upright SB-80, Service & Parts Manual

Page: 33 / 186

SB80 Work Platform - European 3-9
M
AINTENANCE
Section
3.8
3.8 P
LATFORM
D
OWN
L
IMIT
S
WITCH
The Platform Down Switch bypasses the Tilt Sensor
when the platform is fully lowered and closes the cir-
cuit to the Platform Down Relay, which allows high
speed travel, cage trim function and turret rotation.
Figure 3-10: Platform Down Limit Switch
3.9 S
ETTING
H
YDRAULIC
P
RESSURES
Figure 3-11 shows complete hydraulic manifold
assembly.
NOTE: Check hydraulic pressures whenever the
pump, manifold or any relief valve has been
serviced or replaced.
Main Relief Valve
1. Operate the hydraulic system 10-15 minutes to
warm the oil.
2. Install a 0-207 bar (0-3000 PSI) pressure gauge
to the pressure test port.
3. Retract boom completely.
4. While activating the boom retract function, set the
pressure to 193 bar (2800 PSI) maximum by
slowly turning the adjusting screw. Turning the
adjusting screw clockwise increases pressure
and counterclockwise decreases pressure.
5. Remove the pressure gauge and reinstall all
plugs.
Other Relief Valves
1. Operate the hydraulic system 10-15 minutes to
warm the oil.
2. Install a 0-207 bar (0-3000 PSI) pressure gauge
to the pressure test port.
3. Completely extend function to be checked.
4. Continue activating function and set the pressure
by slowly turning the adjusting screw until the cor-
rect pressure reads on the pressure gauge. Turn-
ing the adjusting screw clockwise increases
pressure and counterclockwise decreases pres-
sure.
5. Remove the pressure gauge and reinstall all
plugs.
Counterbalance Relief Valves
1. If any counterbalance relief valve is faulty, com-
pletely lower the jib, and retract the boom.
2. Replace or recalibrate (bench set) the counter-
balance valve.
3. Slowly cycle function related to replaced counter-
balance valve several times to remove air from
system.