Steering Control Unit - Komatsu 830E Shop Manual

STEERING CONTROL UNIT

Removal
Relieve pressure before disconnecting hydraulic
and other lines. Tighten all connections before
applying pressure. Hydraulic fluid escaping
under pressure can have sufficient force to enter
a person's body by penetrating the skin and
cause serious injury and possibly death if proper
medical treatment by a physician familiar with
this injury is not received immediately.
1. Turn keyswitch "Off" and allow 90 seconds for
the accumulators to bleed down. Turn steering
wheel to ensure no oil remains under pressure.
2. Remove capscrews and lockwashers securing
the steering control unit access cover in place
(Access cover is located on the front side of the
operator's cab.) Remove access cover.
NOTE: Clean the steering
surrounding area carefully
contamination of hydraulic oil when lines are opened.
3. Tag all hydraulic lines for proper identification
during installation. Disconnect hydraulic lines
(3, 4, 5, 6, & 7, Figure 5-10) at steering control
unit (2) ports and plug. Move lines clear of
valve.
4. Remove the four mounting capscrews, flatwash-
ers and lockwashers securing the steering con-
trol unit to the mounting bracket. Remove the
steering control unit.
5. Place the steering control unit in a clean work
area for disassembly.
Spline Inspection
Whenever the steering control unit is removed for
service, the steering column shaft should be
inspected for excessive wear.
1. Thoroughly clean splines on steering column
shaft and inspect for damage or excessive
wear.
2. Using an outside micrometer or dial caliper,
measure the outside diameter of the male
splines on the steering column shaft.
• Minimum diameter: 0.950 in. (24.13 mm)
3. If splines are worn more than minimum diameter
specification, replace steering column. (Refer to
Section "N".)
L5-12
control unit and
to help avoid
Steering Component Repair
FIGURE 5-9. STEERING CONTROL UNIT
1. Brake valve
2. Steering Control Unit
3. "LS" Port Hose
4. "L" Port Hose
Installation
1. Lubricate splines of steering column shaft with a
molybdenum disulphide or multi-purpose NLGI
grease.
2. Move steering control unit into position and align
with steering column shaft splines. Secure the
steering control unit in place using four cap-
screws, flatwashers and lockwashers.
3. Check for proper steering wheel rotation without
binding. Be certain wheel returns to neutral after
rotating 1/4 turn left and right. If necessary,
adjust steering unit and/or steering column to
realign column and control unit.
Serious personal injury to the operator or to any-
one positioned near the front wheels may occur if
a truck is operated with the hydraulic steering
lines improperly installed. Improperly installed
lines can result in uncontrolled steering and/or
SUDDEN AND RAPID rotation of the steering
wheel as soon as the steering wheel is moved. It
will turn rapidly and cannot be stopped manually.
5. "T" Port Hose
6. "P" Port Hose
7. "R" Port Hose
L05026