TUBE AS 3278299 - Caterpillar

Table 1
Tools
Pt. No. Description
8T-5320 Hydraulic Test Group
1U-5481 Pressure Gauge Group
Personal injury or death can result if two persons are not used in the following procedure.
Personal injury or death can result from machine articulation or movement.Machine frames can move and a person can be crushed.Connect the steering frame lock link between the front and rear frames before working on machine.
Personal injury or death can result from escaping fluid under pressure.Escaping fluid under pressure, even a very small pin-hole size leak, can penetrate body tissue and cause serious injury and possible death. If fluid is injected into your skin, it must be treated immediately by a doctor familiar with this type of injury.Always use a board or cardboard when checking for a leak.
Before proceeding to the test procedure that follows, complete the procedure:
Machine Preparation for TroubleshootingReference: Refer to the Service Manual moduleTesting and Adjusting, RENR6255, "Machine Preparation for Troubleshooting" for the machine that is being serviced.
Illustration 1 g00856963
Steering Frame Lock is in the Locked position.
Install the steering frame lock in order to keep the machine from turning.
Engage the parking brake. Move the transmission direction selector to the NEUTRAL position.
Illustration 2 g01204900
(1) Steering pump. (2) Pressure tap.
Install a 0 to 40000 kPa (0 to 5800 psi) pressure tap (2).
Start the engine. Operate the engine at high idle. The oil is at normal operating temperature when the hydraulic oil temperature indicator is between the first mark and the second mark.
After the oil has reached normal operating temperature, lower the bucket to the ground. Stop the engine.
Illustration 3 g00858208
(3) Steering control valve. (4) Steering cylinder crossover relief valve.
Note: Steering control valve (3) is located behind the operator's station. Access is gained by opening an access door that is behind the cab.
Illustration 4 g00860313
(5) Locknut. (6) Adjustment screw.
Note: Relief valve (4) is located on the steering control valve.
Loosen locknut (5) on steering crossover relief valve (4). Turn adjustment screw (6) counterclockwise by two full turns. This will lower the setting of the steering crossover relief valve to a setting that is lower than the cutoff pressure of the steering pump.
Start the engine. Raise the bucket and any attachments slightly off the ground. Run the engine at high idle. Note: During the following step, do not keep the steering pump at stall condition for more than ten seconds. If necessary, release the steering wheel and wait for 30 seconds before you repeat the step.
Turn against the steering frame lock. Sustain the FULLY TURNED position in order to obtain a reliable pressure reading.
Record the pressure reading on the pressure gauge. The reading should be lower than 34500 700 kPa (5004 102 psi). Turn adjustment screw (6) slowly in the clockwise direction while you observe the pressure gauge. The reading for the cut off pressure for the steering pump pressure should increase to 31000 750 kPa (4500 109 psi). Then, the pressure should stop rising. Stop turning adjustment screw (6) when the pressure stops rising. Note: The pressure stops rising because the steering pump has