ELECTRICAL AR 3644791 - Caterpillar

Table 1
Required Tools
Part Number Description Qty
1U-5755 Hose 1
6V-4143 Coupler Assemblies 2
Personal injury or death can result if two persons are not used in the following procedure.
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, "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.
Move the machine to a smooth, horizontal location. Move the machine away from other operating machines and away from personnel.
Lower the work tool to the ground. Stop the engine.
Engage the parking brake. Connect the steering frame lock.
Place chocks in front of the wheels and behind the wheels.
Check the hydraulic tank oil level. Make sure that you maintain the correct oil level in the hydraulic tank throughout the air removal procedure.
Raise the hood.
Illustration 1 g03012559
(1) Test Port for the Fan Pump
Install one end of the 1U-5755 Hose to the test port (1).
Illustration 2 g01396536
Location of test port SB
Illustration 3 g01397466
(2) Test port SB
(5) Brake pedal
Install the other end of the hose to the test port (2).
Illustration 4 g01397468
(3) Front axle
(4) Air purge screw
Fasten one end of a transparent tube that is 6.4 mm (0.25 inch) in diameter to the air purge screw (4). Put the other end of the tube into a suitable container for collecting the hydraulic oil.
Start the engine. Run the engine for 1 minute. During this time, the oil from the test port (1) is purging the air from the master cylinder.
Loosen the air purge screw (4).
Depress the brake pedal (5) halfway to the floor. Hold the brake pedal in this position throughout step 13.
As the hydraulic oil flows through the tube, look for air bubbles in the oil. Allow the oil to flow into the container until no air bubbles are visible. Then, tighten the air purge screw and release the brake pedal.
Stop the engine. Remove the hose and the length of tubing.
Remove the chocks.
Perform the braking system test. Refer to Testing and Adjusting, "Service Brake - Test and Adjust". Note: If the brake pedal is spongy during the first hours of operation, perform this procedure again.