CORE ASSEM. 4N5743 - Caterpillar

Table 1
Required Tools    
Part Number     Part Description     Qty    
177-7861     Hose As     1    
6V-4143     Quick Connect Coupler     2    
8T-0856     Pressure Gauge (0 to 6,000 kPa (0 to 870 psi))     1    
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.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the machine. 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 Tools and Shop Products Guide", for tools and supplies suitable to collect and contain fluids in Caterpillar machines.Dispose of all fluids according to local regulations and mandates.
Illustration 1 g01387619
(1) Pressure tap for the pilot hydraulic system
Remove the protective cover from pressure tap (1) . Connect a hose assembly with an 8T-0856 Pressure Gauge (0 to 6,000 kPa (0 to 870 psi)) to pressure tap (1) on the pilot oil manifold.
With the parking brake engaged, start the engine and maintain the engine speed above 1500 rpm with the transmission in NEUTRAL.
Observe the pressure on the gauge. The pressure reading on the gauge with the oil at normal operating temperature should be 3620 70 kPa (525 10 psi).
Illustration 2 g01408775
(2) Pilot oil pressure reducing valve
Illustration 3 g02011455
Pilot oil pressure reducing valve (2) Pilot oil pressure reducing valve (3) Cap (4) Adjusting screw (not shown)
If the pressure reading is not correct, stop the engine. Remove cap (3) and turn adjusting screw (4) (not shown) on pilot oil pressure reducing valve (2) . Turn adjusting screw (4) clockwise to increase the pressure, and counterclockwise to decrease the pressure.
Repeat Step 2 through Step 4 until the correct pressure setting is obtained.
When this test is complete, install cap (3) . Stop the engine and remove the test equipment. Place the protective cover on the pressure tap.