S3015, S3025 and S3035 Demolition and Scrap Shears Caterpillar

Troubleshooting Problem List

Problem List

Note: This section contains the troubleshooting procedures for the hydraulic system of the work tool.

(1) The work tool will not rotate or the work tool will not rotate smoothly.

(2) The work tool rotates faster in one direction.

(3) The jaw of the work tool closes slowly.

(4) The cutting edges do not cut properly.

(5) Blades or tips will not stay tight.

(6) The hydraulic oil overheats.

(7) The work tool operates erratically.

(8) The speed control valve does not operate in high-speed mode upon closing the jaw.

(9) The shear jaw lacks cutting force.

(10) Breaking piercing tip.

(11) Cracking in the housing or either jaws.

Problem 1

The work tool will not rotate or the work tool will not rotate smoothly.

Probable causes

• Check the machine monitor to make sure it is set on the right tool setting.

• Check all lines and hoses on the machine and shear for damages or leaks that may be causing restrictions in the flow of oil to the rotation system of the shear.

• Check for excessive back pressure in the rotation circuit of the machine. Install the shear rotation lock and activate the rotation circuit on the machine, check the pressure on the return flow side at the shear. Pressure should be checked at the shear or as close to the shear as possible. Refer to Operation and Maintenance Manual , M0074514 , "Specifications" for correct pressure.

• Check the pressure in both rotation directions. If the specified pressure is not achieved, following are probable causes.

• The hydraulic oil pressure or oil flow for the work tool is insufficient. Refer to Service Manual, "Host Machine Pressure and Flow - Test".

• The flow control valves are not functioning properly. Refer to Service Manual, "Hydraulic Rotator Oil Flow - Test" for information on testing the flow control valves.

• There is excess back pressure in the system.

• The crossover relief valve is faulty. Refer to Service Manual, "Control Valve Pressure (Hydraulic Rotator) - Test" for information on testing the crossover relief valve.

• The gear and/or bearing is damaged. Inspect the gear and bearing for damage. Refer to Disassembly and Assembly , "Gear and Bearing - Remove and Install".

• The gerotor motor is damaged. Refer to Disassembly and Assembly , "Gerotor Motor - Remove".

• The hydraulic oil is contaminated. Refer to the Service Manual for the host machine for the appropriate information.

Problem 2

The work tool rotates faster in one direction.

Probable causes

• The flow control valves are not functioning properly. Refer to Service Manual, "Hydraulic Rotator Oil Flow - Test" for information on testing the flow control valves.

• The crossover relief valve is faulty. Refer to Service Manual, "Control Valve Pressure (Hydraulic Rotator) - Test" for information on testing the crossover relief valve.

• The auxiliary control valve on the host machine is not functioning properly. Refer to the Service Manual for the host machine for the appropriate information.

Problem 3

The jaw of the work tool closes slowly.

Probable causes

• Check the machine monitor to make sure, that the monitor is set on the right tool setting.

• Check all lines and hoses on the machine and shear for damages or leaks that may be causing restrictions in the flow of oil to the shear.

• Damage on the return side lines on the shear can cause back pressure while closing and could prevent the speed valve from working properly.

• Check the time to open and the time to close. Refer to Operation and Maintenance Manual , M0074514 , "Specifications" to determine proper cycle time for the flow capabilities of the host machine.

• If both the open and close are slow, check the flow from the machine to insure expected flow rate is being delivered to the shear.

• If the close time is slower than the open time, the speed valve may not be working properly. Refer to Testing and Adjusting , "Speed Control Valve (Hydraulic Cylinder) - Test and Adjust"

• If proper flow from the machine has been confirmed and the speed valve has been confirmed to be working properly, check for oil bypassing the seals in either the hydraulic swivel or the cylinder.

• With a flow meter in line with open/close circuit of the shear, fully extend the cylinder and continue holding pressure.

• Flow from the machine with the cylinder fully extended should not exceed 10 L/min (3 US gpm). If this flow rate is exceeded either the swivel seals or the cylinder seals, or both need to be replaced.

• The hydraulic oil flow is insufficient. Refer to Service Manual, "Host Machine Pressure and Flow - Test".

• The speed control valve is out of adjustment. Refer to Service Manual, "Speed Control Valve (Hydraulic Cylinder) - Test and Adjust" for information on testing the speed control valve.

• The cylinder is leaking internally. Refer to Service Manual, "Hydraulic Cylinder Leakage - Test" for information on testing the hydraulic cylinder for leakage.

• There is excess back pressure in the system.

Note: Isolating the swivel and the cylinder to determine which component is allowing the oil to bypass is a costly task. It is recommended to reseal the swivel first and check for oil bypass again. Refer to Operation and Maintenance Manual , M0074514 , "Swivel Reseal". If resealing does not solve the problem, the cylinder seals will need to be replaced. Contact Caterpillar dealer for cylinder repair.

Problem 4

The cutting edges do not cut properly.

Probable causes

• The cutting edges are dull or chipped. Refer to Operation and Maintenance Manual, "Blades and Piercing Tip - Rotate/Replace".

• The cutting edges are not properly aligned. Refer to Operation and Maintenance Manual, "Blades and Piercing Tip - Rotate/Replace".

• The hub is loose. Refer to Operation and Maintenance Manual, "Hub Nut - Check/Tighten".

Problem 5

Blades or tips will not stay tight.

Probable causes

• Bolts have not been installed with proper torque. Refer to Operation and Maintenance Manual , M0074514 , "Blades and Piercing Tip - Rotate/Replace" for torque specification.

• Bolts have been yielded from overuse. Replace with Caterpillar brand bolts.

• Too many shims are behind the blade. There should be a maximum of four shims behind the blades. Use thicker shims.

• Blades are too worn to seat properly in the blade pocket. Replace with a new blade.

• The blade pocket has deformed. Using a blade with worn edges creates excessive force on the blade pocket and can cause the pocket material to deform. Refer to Operation and Maintenance Manual , M0074514 , "Blade Pocket Inspect/Repair" and "Tip Pocket Inspect/Repair".

Problem 6

The hydraulic oil overheats.

Probable causes

• The hydraulic oil pressure is set too high. Refer to Service Manual, "Host Machine Pressure and Flow - Test".

• The hydraulic oil is dirty. Refer to the Service Manual for the host machine for the appropriate information.

• The hydraulic oil level is low. Refer to the Operation and Maintenance Manual for the host machine for the appropriate information.

• The viscosity of the hydraulic oil is incorrect. Refer to the Operation and Maintenance Manual for the host machine for the appropriate information.

• A relief valve on the host machine is stuck open. Refer to the Service Manual for the host machine for the appropriate information.

• The crossover relief valve is faulty. Refer to Service Manual, "Control Valve Pressure (Hydraulic Rotator) - Test" for information on testing the crossover relief valve.

• The hydraulic oil cooler on the host machine is not functioning properly. Refer to the Service Manual information for the host machine.

Problem 7

The work tool operates erratically.

Probable causes

• The hydraulic oil pressure or oil flow is insufficient. Refer to Service Manual, "Host Machine Pressure and Flow - Test".

• The hydraulic oil is contaminated. Refer to the Service Manual information for the host machine.

• The hydraulic oil level is low. Refer to the Operation and Maintenance Manual for the host machine for the appropriate information.

Problem 8

The speed control valve does not operate in high-speed mode upon closing the jaw.

Probable causes

• The pilot pressure of the speed control valve is set too low. Refer to Service Manual, "Speed Control Valve (Hydraulic Cylinder) - Test and Adjust".

• The jaw of the shear is jammed.

• The speed control valve is contaminated.

Problem 9

The shear jaw lacks cutting force.

Probable causes

• Check the machine monitor to make sure it is set on the right tool setting.

• Check all lines and hoses on the machine and shear for damages or leaks that may be causing restrictions in the flow of oil to the shear .

• Damage on the return side lines on the shear can cause back pressure while closing and could prevent the speed valve from working properly.

• Check that the speed valve is working properly. Refer to Testing and Adjusting , "Speed Control Valve (Hydraulic Cylinder) - Test and Adjust".

• If proper flow from the machine has been confirmed and the speed valve has been confirmed to be working properly, check for oil bypassing the seals in either the hydraulic swivel or the cylinder.

• With a flow meter in line with open/close circuit of the shear fully, extend the cylinder and continue holding pressure.

• Flow from the machine with the cylinder fully extended should not exceed 10 L/min (3 US gpm). If this flow rate is exceeded either the swivel seals or the cylinder seals, or both need to be replaced.

• The hydraulic oil pressure is set too low. Refer to Service Manual, "Host Machine Pressure and Flow - Test".

• The cylinder piston seal is leaking. Refer to Service Manual, "Hydraulic Cylinder Leakage - Test".

Note: Isolating the swivel and the cylinder to determine which component is allowing the oil to bypass is a costly task. It is recommended to reseal the swivel first and check for oil bypass again. Refer to Operation and Maintenance Manual , M0074514 , "Swivel Reseal". If resealing does not solve the problem, the cylinder seals will need to be replaced. Contact Caterpillar dealer for cylinder repair.

Problem 10

Breaking piercing tip.

Probable causes

• Improper Piercing Technique. Refer to Operation and Maintenance Manual , M0074514 , "Operating Techniques" , Piercing Material.

• Improper material handling. Refer to Operation and Maintenance Manual , M0074514 , "Operating Techniques" , Material Handling.

• Handling out of balance loads. Out of balance loads will put a side load on the tip which can result in a tip failure. Always carry loads from close to the center of gravity. Refer to Operation and Maintenance Manual , M0074514 , "Operating Techniques" , Material Handling for proper technique.

• Piercing Tip pocket has been deformed. Refer to Operation and Maintenance Manual , M0074514 , "Tip Pocket Inspect/Repair".

Problem 11

Cracking in the housing or either jaws.

Probable causes

• Do not repair without repair procedures from your Caterpillar dealer. When done properly, structural repairs can significantly extend the life of your shear. If done improperly the life of the repair maybe short and can lead to other structural problems. Contact the dealer to get repair procedures from Caterpillar.