ELBOW 4N9692 - Caterpillar

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.
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.
Personal injury or death can result if two persons are not used in the following procedure.
Specifications
Table 1
966M/972M Brake Accumulator Charging Valve Pressure    
Date     Equipment ID Code    
Pump Pressure     Setting     Actual    
Cut-In Pressure     12850 700 kPa (1864 102 psi)        
Cut-Out Pressure    
15195 900 kPa (2204 131 psi)        Introduction
This information includes the following test:
Control Manifold (Charging Valve for the Brake Accumulators) Required Tools
Table 2
Required Tools    
Part Number     Description    
8T-0860     Pressure Gauge (0 TO 40,000-KPA (0 TO 5,800-PSI))    Test Preparation
Refer to Testing and Adjusting, "Brake Accumulator - Test and Charge".Refer to Testing and Adjusting, "System Pressure Release".
Illustration 1 g03124998
Move steering frame lock to the LOCKED position.
Stop the engine. Engage the parking brake.
Depress the brake pedal repeatedly until there is no brake oil pressure.Test Procedure
Illustration 2 g03125004
Location of hydraulic service center
Illustration 3 g03125006
Control manifold (right side view) (1) Brake accumulator pressure tap
Connect a 0 to 40000 kPa (0 to 5800 psi) pressure gauge to brake accumulator pressure tap (1) on the control manifold. The control manifold is located in the service center behind the ladder on the right side of the machine.
Observe the pressure gauge. Before you start the engine, the oil pressure must be 0 kPa (0 psi).
Start the engine and immediately raise to high idle.
The oil pressure must increase to a maximum. Record this pressure. This pressure is the cutout pressure of the brake accumulator charging valve. The correct cutout pressure should be 15195 900 kPa (2204 131 psi).
With the engine in operation, slowly apply the service brakes. Apply the service brakes several times in succession. Verify that the pressure drops consistently. At the point of the specified cut-in, the pressure begins to increase quickly. The correct cut-in pressure should be 12850 700 kPa (1864 102 psi).