Norac UC4 - 4.3 Hydraulic Related Issues

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4.3 HYDRAULIC RELATED ISSUES
 Determine whether the problem is hydraulic or electrical
 If your hydraulic valve has an override pin, use it to manually open the
valve
 If there is no reaction the problem is hydraulic, if the boom moves the
problem may be electrical
NOTE: If there is a bypass valve with the hydraulic system, the bypass valve is also
needed to open at same time as with the tested valve.
 Hydraulic
4.3.1
 Boom(s) will not raise or lower
Possible Cause(s) Suggested Solution(s)
a) Hydraulic oil is not
being supplied to the
NORAC valve block
a) Ensure that oil is being supplied to the
NORAC valve block in the proper
direction (Tank and Pressure lines).
NOTE: If the direction is wrong, the check valve may
prevent oil from flowing through the valve.
b) Hydraulic quick
couplers are not
properly connected
b) Ensure that all quick couplers in the
hydraulic system are properly connected.
c) Not enough back-
pressure to activate
the check valves in
the NORAC valve
block
NOTE: Some Single Acting
valve systems only
c) Place orifices in the “A” lines going to
Tank (“T”) in order to create sufficient
back-pressure to activate the pilot-operated
check valves in the NORAC valve block.
4.3.2
 Booms will not lower
Possible Cause(s) Suggested Solution(s)
Insufficient back-pressure
to activate the pilot-
operated check valves in
the NORAC valve block
Some single acting circuits may require orifices
be placed in the “A” lines going to the tank