CYLINDER HEAD AS 1247373 - Caterpillar

Sudden movement of the machine or release of oil under pressure can cause serious injury to persons on or near the machine.To prevent possible injury, perform the procedure that follows before testing and adjusting the hydraulic system.
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, "Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Cat products.Dispose of all fluids according to local regulations and mandates.
Table 1
Required Tools
Tools Part Number Description Qty
A(1) 198-4234 Digital Pressure Indicator 1
198-4238 Pressure Sensor 0 - 34500 kPa (0 - 5000 psi) 1
B 177-7860 Hose Assembly 1
6V-4143 Coupler 2
8T-0855 Pressure Gauge 0 - 4000 kPa (0 - 580 psi) 1
6V-3989 Fitting 1
C 4C-6500 Digital Thermometer 1
(1) Use either Tool A or Tool B. Tool A was used in this procedure.Test Procedure with Vibratory System OFF
Park the machine on level ground. Move the propel control lever to NEUTRAL. Engage the parking brake.
Illustration 1 g01044794
(1) Charge pressure tap
Connect the 0 - 34500 kPa (0 - 5000 psi) pressure sensor from Tool A to charge pressure tap (1) on the base of the charge filter.
Start and operate the engine at HIGH IDLE at 2370 50 rpm. Monitor the hydraulic oil temperature with Tool C. Operate the machine until the oil temperature reaches 43° 5.6°C (110° 10°F).
Read the pressure on Tool A. The pressure should be 3050 200 kPa (443 293 psi).
Operate the engine at 1200 25 rpm. Read the pressure on Tool A. The pressure should be a minimum of 2070 kPa (300 psi). Note: Low charge pressure at low idle may indicate that the steering pump is not producing sufficient flow.
Illustration 2 g01044008
(2) Charge relief valve
If the high idle pressure is not within the acceptable range, charge relief valve (2) must be adjusted.
Illustration 3 g01044009
(2) Charge relief valve
(3) Poppet
(4) Shims
(5) Spring
Stop the engine. Remove charge relief valve (2). This includes poppet (3), shims (4), and spring (5) from the propel pump.
Add shims (4) to poppet (3) in order to increase the pressure, or remove shims in order to decrease pressure. Note: When the shims are added to the charge relief valve, a 1 mm (0.04 inch) shim is the equivalent of raising the charge pressure by 390 kPa (56.5 psi). When the shims are removed from the charge relief valve, a 1 mm (0.04 inch) shim is equal to reducing the charge pressure by 390 kPa (56.5 psi).
Reinstall charge relief valve (2). This includes poppet (3), shims (4), and spring (5) into the propel pump. Recheck the charge pressure.
When the charge pressure is within the acceptable range, stop the engine. Remove the tooling.