GUIDE-VALVE 2779775 - Caterpillar

To prevent personal injury when checks are made while the machine is in operation, make sure only approved personnel are on the machine. Keep other personnel off the machine and in view of the operator. Make sure checks are done in an open area.
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 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 immediately by a doctor familiar with this type of injury.Always use a board or cardboard when checking for a leak.
Personal injury or death can result from sudden machine movement.Sudden movement of the machine can cause injury to persons on or near the machine.To prevent injury or death, make sure that the area around the machine is clear of personnel and obstructions before operating the machine.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the machine. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.Refer to Special Publication, NENG2500, "Tools and Shop Products Guide", for tools and supplies suitable to collect and contain fluids.Dispose of all fluids according to local regulations and mandates.
The oil pressure for opening the relief valves must be within specifications. Pressures that are too low will cause a decrease in performance. Pressures that are too high will cause a decrease in the life of the hoses and of other components.Problem 1 The winch will not reel out the load or the winch will not reel out the load smoothly.Probable causes
The pilot orifice in the counterbalance valve is plugged.
The counterbalance valve is stuck in the CLOSED position or the adjustment of the opening pressure has been changed.
The static brake will not release due to a worn seal in the brake cylinder.Note: If the seal in the brake cylinder is faulty, you will usually find oil that is leaking from the vent relief valve for the winch.
The static brake will not release as a result of damaged brake discs.Problem 2 Oil leaks from the vent relief valve.Probable causes
The counterbalance valve is stuck in the CLOSED position or the adjustment for the opening pressure has been changed.
The motor seal may be damaged as a result of high back pressure of the case drain circuit or contaminated oil.Problem 3 The brake