CYLINDER 0647084 - Caterpillar

Table 1
Required Tools    
Part Number     Part Description     Qty    
177-7861     Hose As     1    
6V-4143     Couplers     2    
8T-0856     Pressure Gauge     1    
Personal injury can result from hydraulic oil pressure and hot oil.Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system.Make sure all of the work tools have been lowered to the ground, and the oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand.
Personal injury or death can result from machine movement.Place blocks in front of and behind the wheels to make sure the machine does not move while the parking brakes are disengaged.
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.
Move the machine to a hard, level surface.
Engage the parking brake and stop the engine.
Put blocks in front and behind the wheels.
Illustration 1 g00944876
Parking brake control valve (1) Pressure tap (parking brake oil pressure)
Connect a 177-7861 Hose As and an 8T-0856 Pressure Gauge to pressure tap (1) .
Start and run the engine at low idle rpm. Disengage the parking brake. With the oil at normal operating temperature, the pressure should read 3450 140 kPa (500 20 psi).
If the pressure is not correct, engage the parking brake and stop the engine.
Depress the service brake pedal at least 25 times to release any pressure in the brake accumulators.
Move the joystick control lever several times through the full range of travel to release any pressure in the implement pilot circuits.
Move the STIC steering control lever several times in both directions to release any pressure in the steering system.
Press and hold the breaker relief valve to release any pressure in the hydraulic tank.
Illustration 2 g00944878
(2) Parking brake oil pressure reducing valve
Illustration 3 g00915686
(2) Parking brake oil pressure reducing valve (3) Locknut (4) Adjusting screw
Loosen locknut (3) and turn adjusting screw (4) on parking brake oil pressure reducing valve (2). Turn adjusting screw (4) clockwise to increase pressure and counterclockwise to decrease pressure. The correct pressure is 3450 140 kPa (500 20 psi)
Repeat Step 5.
If the pressure reading is correct, engage the parking brake and stop the engine. Remove the test equipment from pressure tap (1). Place the protective cover over the pressure tap.
If the pressure reading is not correct, engage the parking brake and stop the engine. Repeat