Pub. No. 1210 - April 2016
17
RITE-HITE
®
RHH-4000 Dock Leveler Owner’s Manual
HYDRAULIC LEVELER ADJUSTMENTS CONT.
SEQUENCE VALVE ADJUSTMENT
(Controls Lip Extension)
NOTE:
Check oil level before making any adjustments.
NOTE:
Sequence valve is factory set. Adjustments to be
completed by trained technician only.
1. When the leveler is fully raised and the lip does not extend, the
Sequence Valve is set too high.
2. Loosen adjustment nut.
3.
Turn adjustment screw in completely (clockwise) with an allen
wrench. See Figure 17.
4.
Back screw out to get to factory starting point:
For power units built before April 2015: 2-1/2 turns.
For power units built after March 2015: 5-1/2 turns.
Tighten adjustment nut once at factory starting point.
5.
Press RAISE button and run the platform up until the lip extends.
6.
Verify that the lip extends only at the top of the ramp cylinder
stroke. If not, continue with Sequence Valve adjustment.
- Turn adjustment screw out (counter-clockwise) in 1/8 turn
increments. Lip will extend more quickly.
- Turn adjustment screw in (clockwise) in 1/8 turn increments. Lip
will extend more slowly.
7.
Release RAISE button and allow the platform to fall completely
below dock and stop.
8.
Verify that the lip will fall to pendant as the platform is raised up
to store the lip in the keepers. If lip re-extends, turn adjustment
screw in (clockwise) in 1/8 turns and retest.
9.
Re-test the unit several times to verify the setting.
FIGURE 17 - BUCHER POWER UNIT END HEAD (RHH BASE & HYDRARITE)
To Ramp
Cylinder
To Lip
Cylinder
Sequence
Valve
Lip
Pilot-To-Open
Check Valve (3:1)
(HydraRite Shown)
Lip
Pilot-To-Close
Check Valve:
Base: 8:1
HydraRite: 17:1
System Relief Valve
(Set at 1,250 PSI. Do NOT adjust
without permission from Rite-Hite)
IFC/ESB
Option
Port
Flow Control
Lock Nut
Ramp
Pilot-To-Close
Check Valve (3:1)
HYDRARITE
SHOWN
