TUBE AS 2741440 - Caterpillar

Purge Procedure for Two-Wheel Steer
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.
Note: Refer to Operation and Maintenance Manual for your machine.
Illustration 1 g03148477
Rear axle
(1) Left air purge screw
(2) Right air purge screw
Fill the brake fluid reservoir with oil. Add oil to the brake reservoir during the purge procedure in order to maintain the proper level. Refer to Operation and Maintenance Manual, "Recommended Oils", and Operation and Maintenance Manual, "Refill Capacities".
Open the left air purge screw (1) and the right air purge screw (2) while the brake fluid reservoir is being filled. Fill the brake fluid reservoir until oil flows from the air purge screws. Close both of the air purge screws.
Fasten one end of a transparent tube that is 6.4 mm (0.25 inch) in diameter to the left air purge screw (1) and the right air purge screw (2). Put the other end of the tubes into a suitable container for collecting the hydraulic oil.
Illustration 2 g03148520
Brake pedals
(3) Left brake pedal
(4) Right brake pedal
(5) Lock bar
Unlock the lock bar (5).
Depress both pedals five times in a rapid manner. This process is called stroking.
Open the left air purge screw (1). Stroke the left pedal (3) fifty times in a steady manner. Close the left air purge screw (1).
Stroke the right brake pedal (4) five times in a rapid manner.
Open the right air purge screw (2). Stroke the right brake pedal (4) fifty times in a steady manner. Close the right air purge screw (2).
Open the left air purge screw (1). Depress the left brake pedal and hold the left brake pedal (3) 9 cm (3.5 inch) from the rest position. While the left pedal (3) is held down, stroke the right pedal (4) fifty times in a steady manner.
Close the left air purge screw (1) and release the left brake pedal (3).
Stroke the left brake pedal (3) five times in a rapid manner.
Open the left air purge screw (1). Stroke the left brake pedal (3) fifty times in a steady manner. Close the left air purge screw (1).
Repeat Step 12 for right air purge screw.
Close both of the air purge screws. Stroke both pedals ten times in a rapid manner.
Inspect the brake system for leaks.
Fill the brake reservoir with oil.
Lock the lock bar (5).
Perform