©2009 4Front Engineered Solutions, Inc.
January 2009
6004754F — HK and HK-S Hydraulic Dock Leveler, 3 Button — Safe
T
Frame
™
35
TroUbLesHooTing gUiDe,
continued
If motor runs:
2.1 Check hydraulic oil level in reservoir. Add if required.
See Fig. 39 for proper levels and type of oil to be
used.
2.2 Check for loose hydraulic hose fittings or broken
hoses. Repair or replace as required.
2.3 Check for binding in ramp cylinder pivots.
2.4 Check hydraulic bypass pressure and adjust as
required. See Fig. 40.
2.5 Check solenoid valve “STOP” function for
proper operation.
LiP faiLs To exTenD:
Check for damage to lip cylinder and/or pivot pins.
Check for leakage in lip cylinder or hydraulic hose feeding
cylinder.
Check for binding in lip hinge.
Check hydraulic oil level in reservoir. Add if required.
See Fig. 39.
Check hydraulic bypass pressure and adjust as required.
See Fig. 40.
Check lip sequence valve pressure setting. See Fig. 41.
LiP exTenDs before raMP reacHes fULL
aboVe Dock PosiTion:
Check lip sequence valve pressure setting. See Fig. 41.
Check solenoid valve “STOP” function for proper
operation.
LiP faiLs To DroP To THe PenDanT PosiTion
wHen raMP is raiseD froM VeHicLe:
Check for damage to lip cylinder and/or pivot pins.
Check for binding in lip hinge.
Check lip sequence valve pressure setting. See Fig. 41.
2.
1.
2.
3.
4.
5.
6.
1.
2.
1.
2.
3.
3" - 4"
Use type 5606 (low temp.)
hydraulic oil.
Check oil level with ramp
raised and lip extended
Fig. 39
Set bypass pressure at 1650
PSIG with ramp raised and lip
extended
Locking
cap
Bypass pressure
adjusting screw
turn screw clockwise
to increase pressure
1/8 N.P.T.F
gage port
Fig. 40
Set lip sequence pressure at
1350 PSIG. pressure gauge
should read 1350 PSI before
lip begins to extend
Fig. 41