814F Series 2 Wheel Dozer, 815F Series 2 Soil Compactor and 816F Series 2 Landfill Compactor Braking System Caterpillar

Illustration 1	g00882912
Three-Section Vane Pump (1) Pilot and brake section (2) Implement section (3) Steering section

The hydraulic pump on the 814F Series 2 Wheel Dozer, the 815F Series 2 Soil Compactor, and the 816F Series 2 Landfill Compactor is a three-section vane pump. Steering section (3) of the pump supplies oil flow for the hydraulic steering system. Implement section (2) supplies oil flow for the hydraulic implement system. The pilot and brake section (1) supplies oil flow to the implement pilot system and the brake system. Measuring the oil flow can provide an indication of the condition of the pump. An inadequate amount of oil flow from the vane pump indicates that there is excessive internal leakage in the pump. This can be caused by wear or damage of the pump components. The pump flow should be measured at high idle and measured at low idle. Flow loss at low idle is more critical. This test will check the ability of pilot and braking section (1) to supply the proper amount of oil flow to the system.

The vane pump is mounted on the torque converter housing under the cab of the machine.

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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.

Machine Preparation for Testing

1. Park the machine on a smooth, level surface. Move away from other operating machines and away from personnel. Lower the work tools to the ground.

2. Move the steering frame lock to the LOCKED position.

3. Engage the parking brake. Turn the engine start switch to the OFF position.

4. Release all hydraulic pressure before any fitting, any hose, or any component is loosened, tightened, removed, or adjusted.

   ReferenceFor more information about releasing system hydraulic pressure, refer to the Service Manual module Testing and Adjusting, "System Pressure - Release" for the machine system that is being serviced.

5. Move the transmission direction control switch to the NEUTRAL position.

6. Depress the brake pedal repeatedly. This will relieve any pressure that may be present in the brake hydraulic system. In order to release all pressure in the brake accumulators, it may be necessary to pump the brakes 20 to 30 times.

7. Move the implement control levers through the full range of travel. This will relieve any pressure that may be present in the implement hydraulic system.

8. Turn the steering wheel several times in both directions in order to relieve the pressure in the steering system.

9. Depress the plunger on the hydraulic tank breaker relief valve in order to relieve the pressure in the hydraulic oil tank.

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Illustration 2	g00882939
Pressure Reducing Valve (4) Pressure reducing valve (5) Pump supply line (6) Line to accumulator charging valve

10. Pressure reducing valve (4) is located in the compartment behind the cab. Disconnect pump supply line (5) and line (6) to the accumulator charging valve from the tee connector under the pressure reducing valve. Install 6V-9829 Caps on the open ends of the tee connector in order to prevent contamination.

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Illustration 3	g00884543
(7) 4C-9910 Portable hydraulic tester (8) Readout for the flow rate

11. Connect pump supply line (5) to one side of the 4C-9912 Flow Meter. Install a tee connector on the other side of the flow meter. Connect line (6) to the other side of this tee connector. Install a 34500 kPa (5000 psi) pressure gauge to the third side of the tee connector.

12. Use a 4C-9438 Cable in order to connect the flow meter to 4C-9910 Portable Hydraulic Tester (7) .

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Unexpected machine movement can cause injury or death. Activate the parking brake if an adjustment must be made with the engine running. Allow only approved personnel on the machine. Keep other personnel off the machine and in clear view of the service personnel.

Testing Procedure

1. Start the engine. Warm the hydraulic oil to the normal operating temperature.

2. Run the machine at high idle. Use the throttle lock in order to set the engine speed at 2200 rpm.

3. The oil pressure will drop to the standby pressure after the brake accumulators are fully charged. After the brake accumulators are charged, observe the pressure gauge. The standby pressure should be approximately 2900 ± 140 kPa (420 ± 20 psi).

4. The readout for the flow rate (8) should show approximately 22 L/min (5.8 US gpm) at high idle. A 10% decrease in the volume of oil flow is acceptable. If the flow rate is less than 90% of the required rate, the pump should be repaired or replaced.

5. Run the machine at low idle. Use the throttle lock in order to set the engine speed at 1100 rpm. The pressure gauge should show a standby pressure of 2900 ± 140 kPa (420 ± 20 psi).

6. The readout for the flow rate (8) should show approximately 10.9 L/min (2.9 US gpm). A 10% decrease in the volume of oil flow is acceptable. If the flow rate is less than 90% of the required rate, the pump should be repaired or replaced.

7. Turn the engine start switch to the OFF position.

8. Release all hydraulic pressure before any fitting, any hose, or any component is loosened, tightened, removed, or adjusted.

9. Move the transmission direction control switch to the NEUTRAL position.

10. Depress the brake pedal repeatedly. This will relieve any pressure that may be present in the brake hydraulic system. In order to release all pressure in the brake accumulators, it may be necessary to pump the brakes 20 to 30 times.

11. Move the implement control levers through the full range of travel. This will relieve any pressure that may be present in the implement hydraulic system.

12. Turn the steering wheel several times in both directions in order to relieve the pressure in the steering system.

13. Depress the plunger on the hydraulic tank breaker relief valve in order to relieve the pressure in the hydraulic oil tank.

14. Remove the test equipment. Connect pump supply line (5) and line (6) to the tee connector under pressure reducing valve (4) .

15. Move the steering frame lock to the UNLOCKED position.

    Note: The service brakes should be checked for proper operation before the machine is put back in operation.