LINK AS-TRACK 7G6441 - Caterpillar

Personal injury or death can result from escaping fluid under pressure.Escaping fluid under pressure, even a very small pin-hole size leak, can penetrate body tissue and cause serious injury and possible death. If fluid is injected into your skin, it must be treated 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.
This section provides probable causes to known problems. Since there may be several probable causes, specific inspections or instrument tests may be recommended. These inspections and tests will help to identify the causes that are most probable.Note: Before making any tests of the service braking system, ensure that the oil in the system is at operating temperature.Note: Check for correct accumulator charging pressure and correct nitrogen charge in the accumulator.ReferenceRefer to Systems Operation, Testing and Adjusting, "Brake Accumulator - Test and Charge" for the machine that is being serviced.Note: Ensure that you use an oil with the correct viscosity for the operating conditions.ReferenceRefer to Operation and Maintenance Manual, "Lubricant Viscosities and Refill Capacities" for the machine that is being serviced.Troubleshooting
Problem: Service brakes are slow to apply.
Probable causes:
No nitrogen gas charge in the service brake accumulators.
The brake discs and associated components in the brake group are excessively worn.
Hydraulic lines or fittings leaking.
Damaged hydraulic brake lines.
Air in the brake system.Problem: The accumulator pressure will not reach cut-out pressure at low idle, typically causing a Warning Category 3 to occur. The parking brake may also engage.
Probable cause:
When the hydraulic oil is hot and engine is running at low idle, pump output is not sufficient to overcome the pumps own internal losses.Problem: The front service brakes do not operate, and the warning system is not activated.
Probable causes:
The front brake groups are damaged.
The lines to the front service brakes are obstructed.
The front circuit of the service brake control valve is faulty.Problem: The rear service brakes do not operate, and the warning system is not activated.
Probable causes:
The rear brake groups are damaged.
The lines to the rear service brakes are obstructed.
The rear circuit of the service brake control valve is faulty.Problem: Service brakes slip, and the warning system is not activated.
Probable causes:
The brake discs in the brake groups are worn.Problem: The service brakes are not applied evenly.
Probable causes:
The brake discs and associated components in the brake groups are excessively worn.
The service brake control valve is