REPAIR KIT 8U9428 - Caterpillar

Table 1
Required Tools    
Tool     Part Number     Part Description     Qty    
A     Test Gauge Hose    
6V-4143 Coupler (1)     2    
6V-3079 Hose Assembly (1)     1    
6V-3966 Fitting (1)     1    
B     Test Gauge    
8T-0852 Pressure Gauge (2)     1    
( 1 ) Part of 1U-5482 Pressure Adapter Group
( 2 ) Part of 1U-5481 Pressure Gauge Group
Escaping fluid under pressure, even a pinhole size leak, can penetrate body tissue, causing 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 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 Tools and Shop Products Guide" for tools and supplies suitable to collect and contain fluids on Caterpillar products.Dispose of all fluids according to local regulations and mandates.
Machine Preparation
Prepare the machine for testing. Complete the following procedures that are specified in the Service Manual for the machine that is being serviced.
Testing and Adjusting, "Machine Preparation for Troubleshooting"
Testing and Adjusting, "System Pressure - Release"
The pilot pump supplies hydraulic oil to the accumulator charging valve in the brake system, to the implement pilot system, and to the steering pilot system.This procedure will isolate the implement pilot control valve from the braking system. This procedure will also isolate the pilot control valve and the selector and pressure control valve in the steering system from the brake system. These components must be isolated in order to check for excessive internal leakage.
Illustration 1 g00467820
Location of the Implement Pilot Control Valve (1) Supply line to the Implement pilot control valve. (2) Implement pilot control valve. (3) Supply line to the steering pilot control valve.Implement pilot control valve (2) is located underneath a cover that is between the front wheels of the machine.
Plug pilot supply line (1) at implement pilot control valve (2) .
Illustration 2 g00491427
Location of the Brake Components (right side of cab) (4) Pressure tap for the service brake system. (5) Brake accumulator charging valve.
Connect a 0 to 40000 kPa (0 to 5800 psi) pressure gauge at pressure tap (4) on brake accumulator charging valve (5) .
Start the engine.Note: The cut out pressure of the accumulator charging valve is 14485 345 kPa (2100 50 psi).
If the low oil pressure warning does not exist, and the brake oil pressure climbs to the cut out pressure of the accumulator charging valve, there is a path for excessive leakage in the pilot system. Proceed to Step 6.
If the low oil pressure warning still exists, then the brake and implement pump needs to be tested.Reference: For more information on testing the brake and implement pump, refer to the Service