New Holland Workmaster 50, Service Manual

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Steering - Steering control
Steering control - Troubleshooting
Problem Possible Cause Correction
Steering wheel is heavy
to turn No or insufficient oil pressure
a) Pump does not run
b) Pump defective
c) Pump runs in the wrong
the direction
d) Pump is worn out
e) Pump is under dimensioned
Start up pump (loose V-belt)
Repair or replace pump
Correct direction of rotation of pump or re-
place pump
Replace pump
Install a larger pump (examine pressure
need and flow)
Pressure relief valve is stuck in open posi-
tion or setting pressure is too low Repair or clean pressure relief valve. Ad-
just the valve to the correct pressure
Priority valve is stuck in open position Repair or clean the priority valve
Too much friction in the mechanical parts of
the vehicle Lubricate bearings and joints of steering
gear or repair if necessary. Check steer-
ing column installation
Emergency steering balls missing Install new balls
Combination: Downstream steer-
ing unit with suction valve and differential
cylinder are inexpedient Change cylinder type (through going piston
rod). If necessary use two differential cylin-
ders
Hard point when starting
to turn the steering wheel Spring force in priority valve too weak Replace spring by a stronger one ( 4 bar
( 58 psi ) , 7 bar ( 102 psi ) and 10 bar
( 145 psi ))
Air in LS and /or PP pipes Bleed LS and PP pipes
Clogged orifices in LS or PP side priority
valve Clean orifices in spool and in connecting
plugs for LS and PP
Oil is too thick (cold) Let motor run until oil is warm
Regular adjustments of
the steering wheel are
necessary (“snake-like
driving”) Leaf spring without spring force or broken Replace leaf springs
Spring in double shock valve broken Replace shock valve
Gear wheel set worn Replace gear wheel set
Cylinder seized or piston seals worn Replace defective parts
Neutral position of
steering wheel cannot
be obtained, i.e. there is a
tendency of “Motoring” Steering Column and steering unit out of
line Align the steering column with steering unit
Too little or no play between steering col-
umn and steering unit input shaft Adjust the play and, if necessary, shorten
the splines journal.
Pinching between inner and outer spools Contact your authorised NEW HOLLAND
“Motoring” effect. The
steering wheel can turn
on its own Leaf springs are stuck or broken and have
therefore reduced spring force Replace leaf springs
Inner and outer spools pinch, possible due
to dirt Clean steering unit or contact your NEW
HOLLAND dealer
Return pressure in connection with the
reaction between differential cylinder and
steering unit too high Reduce return pressure, change cylinder
type or use a non-reaction control unit
Backlash
Cardan shaft fork worn or broken Replace cardan shaft
Leaf springs without spring force or broken Replace leaf springs
Worn splines on the steering column
Replace steering column
“Kick-back” in steering
wheel from system. Kicks
from wheels Fault in the system
Contact your authorised NEW HOLLAND
Heavy kick-back in
steering wheel in both
directions Wrong setting of cardan shaft and gear
wheel set Correct setting as shown in service manual
Turning the steering
wheel activates the
steered wheels opposite Hydraulic hoses for the steering cylinders
have been switched around Reverse the hoses
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