DAF CF65, CF75, CF85 Series . Manual — part 952
©
200423
3-1
Inspection and adjustment
STEERING GEAR, GENERAL
ΧΦ65/75/85 series
7
2
3. INSPECTION AND ADJUSTMENT
3.1 INSPECTION OF THE STEERING GEAR USING A PRESSURE GAUGE
Note:
A quick check of the steering gear can be carried
out using a pressure gauge. To this end, the
same pressure gauge can be used as for the
adjustment of the wheel deflection limiting valves.
A pressure gauge allows you to carry out only a
limited number of measurements. To test the
steering pump (output in l/min. at a certain
pressure) and the steering box condition (internal
sealing, plays) you will need a test equipment
case.
If the cause of the problem cannot be found using
the pressure gauge, the steering gear should be
diagnosed using the test case.
After having turned the steering
wheel with a torque wrench with a
dial, always check the tightening
torque of the steering wheel nut.
Items requiring special attention when
connecting the pressure gauge
1.
Clean the delivery line connection that is
going to be disconnected.
2.
Check the steering box attachment.
3.
Check the hydraulic central position.
4.
Place proper turning plates under the
vehicle's steerable wheels.
Block the vehicle so that it cannot
slide off the jack or the turning
plates.
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STEERING GEAR, GENERAL
3-2
©
200423
Inspection and adjustment
2
ΧΦ65/75/85 series
7
Connecting the pressure gauge
Only use couplings and lines which
are suited to the maximum system
pressure.
1.
Connect the pressure gauge, using special
tool (DAF no. 0535653) to the T-piece in the
delivery line. Make sure that as little steering
oil as possible runs off and clear away spilt
oil.
2.
Check the steering oil level in the reservoir
and top up if necessary.
3.
Bleed the steering gear, see chapter
'Draining, filling and bleeding'.
Bringing the steering oil up to the test
temperature
1.
Set the engine speed to 1200 - 1400 rpm.
2.
Activate the steering gear for 5 seconds at its
maximum, making sure that the pressure
does not exceed 50 bar. Do not touch the
steering wheel for 5 seconds.
3.
Repeat this action until the lines are at least
hand warm.
Measuring the circulation pressure
1.
Run the engine at idling speed.
2.
Check the circulation pressure. Compare the
reading with the specified value, see
'Technical data'.
Inspection of front axle bearings
1.
Run the engine at idling speed.
2.
Turn the steering gear carefully from the
central position to both maximum wheel
deflections.
3.
Check whether the control pressure rises
evenly.
}
S7 00 585
©
200423
3-3
Inspection and adjustment
STEERING GEAR, GENERAL
ΧΦ65/75/85 series
7
2
Testing the maximum system pressure
1.
Run the engine at idling speed.
2.
Activate the steering gear and fit a 15-mm
filler piece, special tool (DAF no. 0535996),
between the adjusting bolt or the axle stop on
the swivel axle and the axle housing stop.
Be careful when fitting the 15-mm
filler piece between the adjusting
bolt and the axle stop, because there
is a danger of limbs getting trapped.
3.
Fit a torque wrench with a dial to the steering
wheel attachment bolt. Tighten the nut to a
tightening torque of 45 Nm on the torque
wrench.
4.
Take the maximum pressure reading on the
pressure gauge (the maximum pressure
should not be continued for more than 5
seconds). Compare the reading with the
specified value, see 'Technical data'.
Note:
If the measured value deviates more than 10%
from the specified value, the cause should be
identified using the test case.
5.
Repeat the measurement using the 15-mm
filler piece at the other side of the front axle.
6.
Retighten the steering wheel attachment bolt
to the specified tightening torque. See
'Technical data'.
7.
Remove the pressure gauge and
the T-piece.
8.
Check the steering oil level in the reservoir
and top up if necessary.
9.
Bleed the steering gear, see chapter
'Draining, filling and bleeding'.
S7 00 598
45Nm
45Nm
S7 00 565
}
STEERING GEAR, GENERAL
3-4
©
200423
Inspection and adjustment
2
ΧΦ65/75/85 series
7
3.2 INSPECTION OF STEERING GEAR USING THE TEST CASE
Note:
The test case makes it possible to:
-
inspect the condition of the entire steering
gear on a regular basis.
-
make a reliable diagnosis if the steering gear
does not function properly.
An inspection using a pressure gauge will only
provide information on system pressures, which
in some cases might be insufficient to find a
defect. However, it provides no information on the
condition of the steering pump (output) and the
steering box (internal leakage). As a result, in
practice steering pumps and steering boxes are
often replaced unnecessarily.
Electronic test case 'Servotest 550'
The inspection referred to below is carried out
using the 'Servotest 550' test case. It is also
possible to inspect the steering gear using similar
equipment able to perform the same
measurements as the 'Servotest 550'.
The test case is connected to the delivery line,
which runs from the steering pump to the steering
box.
The line connection "Eingang" is fitted with a filter
which, depending on the degree of impurity of the
oil, should be regularly cleaned.
The 'Servotest 550' test case consists of the
following parts:
50
100
150
200
250
5
10
15
20
25
9
7
8
2
4
6
5
10
11
1
3
S7 00 020
1.
Connection "Eingang" (input)
2.
Connection "Ausgang" (output)
3.
Connection "Tank"
4.
Cock
5.
Non-return valve (throttle)
6.
Pressure-limiting valve 120/150 bar
(switch over)
7.
Output meter 0.01 - 100 l/min
8.
Switch for output meter
9.
Low-pressure gauge 0-25 bar
10.
High-pressure gauge 0-250 bar
11.
Temperature gauge 0-120
C
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