PLUNGER 3041928 - Caterpillar

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.
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.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.Refer to Special Publication, NENG2500, "Caterpillar Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Caterpillar products.Dispose of all fluids according to local regulations and mandates.
Note: Use the information in the reference to prepare the machine for this test. Also, use the information in the reference to relieve any hydraulic pressure that may be in the steering system.Reference: For the correct procedure to relieve any hydraulic oil pressure that may be in the steering system, refer to the Service Manual module for Testing and Adjusting, "Machine Preparation for Troubleshooting" for the machine that is being serviced.
Table 1
Required Tools    
Part Number     Description    
198-4240     Digital Pressure Indicator    
8T-0854     Pressure Gauge    
8T-0856     Pressure Gauge    
Start the engine. Position the machine so that the machine is pointing straight ahead.
Operate the engine at high idle. Move the tilt control lever to the TILT BACK position in order to increase the oil to normal operating temperature. 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 and any attachments to the ground.
Stop the engine.
Illustration 1 g00294202
Steering Frame Lock in the LOCKED Position (1) Steering frame lock.
Move steering frame lock (1) to the LOCKED position.
Engage the parking brake. Move the transmission direction selector to the NEUTRAL position.
Illustration 2 g00444025
Bottom View of Pilot Control Valve (Arrow) Front of The Machine (2) Pressure tap for neutral pilot pressure. (3) Supply pressure for the pilot valve. (4) Adjustment screw for the neutral pilot pressure. (5) Locknut.
Attach a 0 to 6000 kPa (0 to 870 psi) pressure gauge to pressure tap (3). Pressure tap (3) is located on the rear side of the pilot control valve. Pressure tap (3) is supply pressure for the pilot valve.
Bumping or turning the steering wheel could cause excessive oil pressure in the hydraulic oil line that connects to the pressure gauge. The excessive oil pressure could cause damage to the pressure gauge.Do not bump or turn the steering wheel during the following steps.
Attach a 0 to 1000 kPa