Upright SL26SL, Service & Parts Manual

Page: 32 / 104

3-8 SL26/30SL Work Platform
M
AINTENANCE
Section
3.8
Brake Pressure Reducing Valve
(Figure 3-5 & Figure 3-7)
1. Using two 1-ton jack stands and a 2-ton jack, jack
the work platform up to raise the rear wheels off
the ground and block the machine securely.
2. Remove the outlet hose from the backside of the
Brake Release Pump and install a 41.4 (0-600
psi) gauge assembly in-line with a tee fitting.
3. Remove the plug on the end of the Brake Relief
Valve.
4. With the engine running, position the Control
Lever to REVERSE and hold.
5. While holding the Control Lever in REVERSE , set
the pressure to 24-33 bar (350-480 psi) maxi-
mum by slowly turning the adjusting screw, clock-
wise to increase pressure.
6. Replace the valve plug.
7. Remove the gauge and tee fitting and reinstall
the hose.
8. Remove the jack stands and lower the machine.
Figure 3-7: Brake Release Pump
3.8 S
WITCH
A
DJUSTMENTS
Proportional Control Adjustment
(Figure 3-8)
To perform the adjustment, the control box must be
opened by removing the screws at the corners of the
controller and rotating the top forward to expose the
proportional controller. Remove the potting material
from the potentiometer adjustment screws if neces-
sary.
Please follow the exact sequence outlined below
when making controller adjustments. It is possible
that making an adjustment to one setting could affect
another, so please verify that all speeds are correct
before completing the adjustment procedure. For all
potentiometers, clockwise movement will increase,
and counterclockwise movement will decrease the
speed of that function.
Figure 3-8: Proportional Controller Adjustment
1. Set the THRESHOLD potentiometers so that the
machine is just starting to move when the control-
ler is stroked slightly forward.
2. Mark out a 6.1 m (20 foot) course on the ground
to use for step numbers 3, 4 and 5.
3. Set the HI RANGE potentiometers so that the
machine will travel 6.1 m (20 ft.) in 5 to 7 seconds
at full controller deflection.
Note: The machine should be running full speed
before crossing the starting line, and should
run perfectly straight through the course.
HI Range Pot
THRESHOLD Pot
LO Range Pot