Test and Repair Procedures for 3S6224 and 8S8033 Hydraulic Pump Groups{0616} Caterpillar

Introduction

This Special Instruction contains testing, troubleshooting, repair procedures and parts information for 3S6224 and 8S8033 Hydraulic Pump Groups for 3600 Engines.

For information about parts listed without Caterpillar part numbers, please call the source companies as listed.

Do not perform any procedure outlined in this publication or order any parts until you have read and understand the information contained within.

Reference: Engine Service Manuals.

Important Safety Information

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To prevent personal injury, follow the guidelines below. Follow the manufacturer's recommendations when connecting this unit to hydraulic cylinders, hydraulic pullers or other attachments.

Hydraulic Hose

Before operating the pump, all hose connections must be tightened with the proper tools. Do not over tighten. Connections should only be tightened securely and leak-free. Overtightening can cause premature thread failure or high pressure fittings to split at pressures lower than their rated capacities.

Always shut off the electric motor before breaking any connection in the system.

Should a hydraulic hose ever rupture, burst or need to be disconnected, immediately shut off the pump. Never attempt to grasp a leaking pressurized hose with your hands. The force of escaping hydraulic fluid could cause serious injury.

Do not subject the hose to potential hazard such as fire, sharp surfaces, extreme heat or cold or heavy impact. Do not let the hose kink, twist, curl or bend so tightly that oil flow within the hose is blocked or reduced. Periodically inspect the hose for wear, because any of these conditions can damage the hose.

Do not use the hose to move attached equipment. Stress can damage the hose, causing personal injury.

Hose material and coupler seals must be compatible with the hydraulic fluid used. Hoses also must not come in contact with corrosive materials such as creosote-impregnated objects and certain paints. Consult the manufacturer before painting a hose. Never paint the couplers. Hose deterioration due to corrosive materials can result in personal injury.

Pump

Do not exceed the hydraulic pressure rating noted on the pump nameplate or tamper with the internal high pressure relief valve. Creating pressure beyond rated capacities can result in personal injury.

Before replenishing the oil level, retract the system to prevent overfilling the pump reservoir. An overfill can cause personal injury due to excess reservoir pressure created when cylinders are retracted.

Cylinder

Do not exceed the rated capacities of the cylinders. Excess pressure can result in personal injury.

Do not set poorly balanced or off-center loads on a cylinder. The load can tip and cause personal injury.

Power Supply (Electric)

Never use an ungrounded power supply with this unit.

The pump must be compatible with existing line voltage.

Disconnect the pump from the power supply when performing maintenance or repair on the unit.

If the unit's power supply is damaged or the inner wiring is exposed in any way, replace immediately.

Any electrical work must be done by a qualified electrician.

If the power cord is damaged or wiring is exposed, replace or repair immediately.

Changing the voltage on the jet motor (single or three phase) is a complicated and, if not done correctly, dangerous procedure. Consult Owatonna Tool Company Technical Services for specific information before attempting any rewiring. Rewiring voids CSA (Canadian Standards Association) approval.

All voltages must be wired for clockwise rotation when viewed from the lead end (top) of the motor.

Check the total amperage draw for the electrical circuit you will be using. (For example: Do not plug a motor or motors that may draw 25 amps into a 20 amp fused electrical circuit.)

Do not attempt to increase the powerline capacity by replacing a fuse with another fuse of higher value. Overheating of the powerline and the possibility of a fire will result.

To rewire a motor from one voltage to another or when a flow control valve is changed from manually controlled to solenoid controlled, consult the electrical schematic in the parts list.

Circuit Breakers: If motor stops due to an overload or power outage:

Universal Motor: Move motor switch to OFF and control valve to neutral. Let motor cool or wait until power is restored. Reset circuit breaker switch in power panel. (The pump motor does not have a circuit breaker.)

Single-phase Motor: Thermal overload switch will break circuit to the motor. Move motor switch to OFF and control valve to neutral. Allow motor to cool before switching on again or wait until power is restored.

Three-phase Motor: A magnetic starter switch breaks circuit to the motor. Move the motor switch to OFF and control valve to neutral. Remove the cover on motor control box. Let the motor cool or wait until power is restored. One of three reset buttons must be pushed in to reset motor. Replace cover.

Operation

Filling The Reservoir

NOTE: The pump has been shipped without oil in the reservoir. High-grade hydraulic oil has been shipped with the pump in a separate container. If additional oil is required, use an approved, high-grade SAE 10W hydraulic oil such as one of the following or equivalent.

1. Clean the area around the filler cap to remove all dust and grit. Any dirt or dust in the oil can damage the polished surfaces and precision-fit components of this pump.

2. Retract all cylinders to return position.

3. Remove the filler cap and insert a clean funnel and filter. Fill with hydraulic oil to within 12.70 mm (0.5 in) from the top of the filler hole. Replace filler cap with the breather-hole in the filler cap open.

4. Cycle the pump (with cylinders attached) several times. Retract the cylinders and check the oil level in the pump reservoir and fill, if required.

Hydraulic Connections

1. Clean all the areas around the oil ports of the pump and cylinder.

2. Inspect all threads and fittings for signs of wear or damage and replace as needed.

3. Clean all hose ends, couplers or union ends.

4. Remove the thread protectors from the hydraulic oil outlets. Connect the hose assembly to the hydraulic oil outlet and couple the hose to the cylinder. Although a high-grade, non-hardening thread sealant is preferred, Teflon tape may be used to seal hydraulic connections if only one layer of tape is used. Apply carefully to prevent the tape from being pinched by the coupler and broken off inside the pipe end. Any loose pieces of tape could travel through the system and obstruct the flow of oil.

Valve Options

Automatic Dump Valve

When the pressure switch setting is reached, the switch shuts off the motor. All pressure is automatically dumped. Turn the adjusting screw clockwise to increase pressure; turn the adjusting screw counterclockwise to decrease pressure. Refer to section "Adjusting The Pressure Switch" in this document.

"Posi-Check" Valves

"Posi-Check" is a valve feature that holds the load while shifting from "Advance" to "Hold" positions.

Figure 1

If a "Posi-Check" valve is used, a hydraulic gauge shows zero pressure when the valve is switched to the neutral (hold) position. Cylinder pressure is held without loss. To install a hydraulic gauge, remove the pipe plug from the gauge port. Apply 5P3413 Pipe Sealant or Teflon tape to the gauge threads, insert into the gauge port and tighten with a wrench. See Figure 1.

NOTE: Seal all external pipe connections with a high-quality, non-hardening pipe sealant. Teflon tape can also be used to seal hydraulic connections if only one layer of tape is used. Apply the tape carefully to prevent if from being pinched by the coupler and broken off inside the pipe end. Any loose pieces of tape can travel through the system and obstruct the flow of oil.

Priming The Pump

When operating the pump for the first time:

1. Valve and hose connections must be tight and the reservoir must be filled to the proper oil level. Start the motor.

2. Jog the pump several times to build pressure. If the pump does not build pressure, it may not be primed. Disconnect a hose from the system and route it back to the pump reservoir. Run the pump until a steady flow of oil is observed free of suspended air bubbles. Reconnect the hose to the system.

3. Run cylinder out to its full travel several times to eliminate air from the system. For more complete instructions, refer to section "Bleeding Air From The System".

4. The pump is ready to be put into operation.

NOTE: After eliminating trapped air from a large system, retract the cylinders and refill the pump reservoir to within 12.70 mm (0.5 in) from the top of the filler hole.

Adjusting The Pressure Regulating Controls

The pressure regulating valve can be adjusted to bypass oil at a given pressure setting while the pump continues to run. The pressure switch can be adjusted to stop the pump motor at a given pressure setting. To ensure accuracy and a low pressure differential [approximately 408.00 N·m (300 lb ft)] throughout the pressure range [1360 to 13 600 N·m (1,000 to 10,000 psi depending on the pump model], the pressure switch should be used with the pressure regulating valve. The pressure switch must be set at a pressure lower than the pressure regulating valve to work properly.

Adjusting The Pressure Regulating Valve

NOTE: For easy adjustment of the pressure regulating valve, always adjust the pressure by increasing to the desired pressure setting.

1. Loosen the locknut on the pressure regulating valve (C) and back the adjusting screw (B) out a few turns with a screwdriver by turning in a counterclockwise direction. This will decrease the setting to a lower than desired pressure.

2. The pump must be completely connected. Set the motor control toggle switch on "Run" and push the "Start" button.

3. With a screwdriver, slowly turn the adjusting screw (B) in a clockwise direction. The gradually increases the pressure setting. When the desired pressure is reached, lock the adjusting screw in position by tightening the locknut.

NOTE: The pressure range is from 1360 to 13 600 kPa (1,000 to 10,000 psi) depending on the pump model. The pressure switch must be set at a higher pressure than working range to prevent shut down during adjustment. It is also possible to bypass the pressure switch contacts by holding the start switch or remote control switch so that the motor runs continuously.

Adjusting The Pressure Switch

The pressure switch should be used with the pressure regulating valve. A pressure switch can be used alone for operating electrical devices such as motors, solenoids, relays, etc., which are located elsewhere in the circuit.

1. Loosen the locknut on the pressure switch (D) and turn adjusting screw (A) in a clockwise direction. This increases the pressure setting to a higher than desired pressure.

2. Adjust the pressure regulating valve to the desired pressure setting by using the procedure in section "Adjusting The Pressure Regulating Valve".

3. With the pump running and bypassing oil at the desired pressure, slowly turn the pressure switch adjusting screw (A) in a counterclockwise direction, decreasing the pressure switch setting until the pump motor shuts off. Then lock the adjusting screw (A) in position by tightening the locknut.

4. Release the pressure. Run the pump to check the pressure setting and cut-out of the motor. It may be necessary to make a second adjustment.

NOTE: When the pressure switch setting is reached, the motor will shut off. However, the "coast" of the motor continues to deliver oil for a brief period. The pressure regulating valve bypasses this surplus oil, preventing it from going into the system. As a result, the pressure differential can be held to approximately 408 N·m (300 lb ft).

Preventive Maintenance

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Disconnect the pump from the power supply before performing maintenance or repair procedures. Electrical shocking can cause personal injury. Repairs and maintenance are to be performed in a dust-free area by a qualified technician.

Bleeding Air From The System

Air can accumulate in the hydraulic system if the reservoir oil level is too low. This air causes the cylinder to respond in an unstable or slow manner. To remove the air:

1. The hydraulic cylinder(s) must be positioned on their side(s) with the couplers located upward.

2. Remove any load from the cylinder(s) and cycle the hydraulic system through several cycles (fully extend and retract the cylinders).

NOTE: Some of the single-acting spring return cylinders have a cavity in the rod that forms an air pocket. This type of cylinder must be positioned upside down when the hydraulic system is bled.

Hydraulic Fluid Level

1. Check the oil level in the reservoir after every 10 hours of use. Proper oil level is within 12.70 mm (0.5 in) of the filler plug when all cylinders are retracted.

2. Drain, flush and refill the reservoir with an approved, high-grade SAE 10W hydraulic oil after approximately every 300 hours of use. The frequency of oil changes will depend upon the general working conditions, severity of use and overall cleanliness and care given the pump. Refer to section "Filling The Reservoir" for oil recommendations.

Maintenance Cleaning

1. Keep the pump's outer surface as free from dirt as possible.

2. Seal all unused couplers with thread protectors.

3. Keep all hose connections free of dirt and grime.

4. The breather hole in the filler cap must be clean and unobstructed at all times.

5. Equipment connected to the pump must be kept clean.

6. Use only an approved, high-grade SAE 10W hydraulic oil in this pump. Change as recommended (every 300 hours).

Draining And Flushing The Reservoir

NOTE: Clean the pump exterior before the pump interior is removed from the reservoir.

1. Remove the ten screws fastening the motor and pump assembly to the reservoir.

NOTE: Do not damage the gasket or bump the filter or pressure regulating valves when lifting the pump and motor off the reservoir.

2. Clean the inside of the reservoir and fill with a suitable flushing oil. Rinse the filter clean.

3. Place the pump and motor assembly back onto the reservoir and secure with two machine screws assembled on opposite corners of the housing.

NOTE: The hydraulic flow control valve must be in the neutral position for the following step. If the pump is equipped with a valve that has only an advance or retract position, place the valve in the advance position and connect a hose to the advance port on the valve. Place the other end of the hose into the oil filler plug hole.

4. Run the pump for several minutes. Then disconnect the motor and pump assembly and drain and clean the inside of the reservoir.

5. Fill the reservoir with an approved, high-grade SAE 10W hydraulic oil. Refer to section "Filling The Reservoir". Place the pump and motor assembly (with gasket) on the reservoir and install the ten screws. Tighten the screws evenly.

Adding Oil To The Reservoir

1. Cylinder(s) must be fully retracted and the power supply disconnected when adding oil to the reservoir.

2. Clean the entire area around the filler plug before removing the filler plug.

3. Use a clean funnel with filter when adding oil.

4. Use only an approved, high-grade SAE 10W hydraulic oil. Refer to section "Filling The Reservoir".

Sound Reduction

The electrically powered hydraulic pump operates in the 90 to 95 dBA range. If further sound reduction is desirable, any of the following options will help reduce the sound level.

1. Install a pressure switch. The switch will shut the motor off automatically when maximum pressure is reached (hold cycle).

2. Use a 3450 rpm, 1 1/2 horsepower, 115 VAC, 60 Hz, 1-phase pumping unit.

3. Use a 3450 rpm, 1 1/2 horsepower, 230 VAC, 60 Hz, 3-phase pumping unit.

4. Install casters (two gallon reservoir only) to reduce the noise level.

Installation Schematics

NOTE: These schematics are only for standard pumps. Special applications may require different schematics that are not shown here.

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To help avoid personal injury, all electrical work must be done by a qualified electrician.

Electrical schematic for units with a manifold, 2-way, 3-way, 4-way manual or automatic valve and no other electrical accessories.

Electrical schematic for units with a 3-position, 3-way manual valve with motor switch (Ref. 9583/30601).

Electrical schematic for units with a pressure switch (Ref. 9624/40281 old style and 9625/52203 new style).

NOTE: Regardless of circuit design, pressure switch must be installed so that motor will shut off when pressure setting is obtained.

Electrical schematic for units with motor remote control.

Electrical schematic for units with a 2-position, 3-way solenoid valve (Ref. 9579/42621).

Electrical schematic for units with a 2-position, 4-way solenoid valve (Ref. 9592/61-04).

Electrical schematic for units with a 3-position, 3-way solenoid valve (Ref. 9605/41825) or a 3-position, 4-way valve (Ref. 9607/50951 and 9590/31057-C1-B).

Electrical schematic for units with motor remote control 24 volt secondary.

Troubleshooting

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To prevent personal injury, any repair work or troubleshooting must be done by qualified personnel familiar with this equipment. To prevent personal injury, disconnect power supply before removing electrical cover. Use the proper gauges and equipment when troubleshooting.

NOTE: Depending on the type of pump, it is often best to check for leaks by using a hand pump and applying pressure to the suspect area without the motor running. Watch for leaking oil and follow it back to its source. Plug the outlet ports of the pump when checking for leakage to determine if the leakage is in the pump or in the cylinder or tool. Refer to the Parts List when using this troubleshooting section.

3S6224 and 8S8033 Electric Hydraulic Pump Groups

NOTE: For replacement parts in the following charts listed without Caterpillar part numbers, contact:

NOTE: Reference Caterpillar Part No. 3S6224 (115 V) or 8S8033 (230 V) Hydraulic Pump Group when calling.

NOTE: A 2P2287 Valve Kit is available for the four-way directional valve body Model No. 31094 and 9586.

NOTE: A 1U9903 Repair Kit is available for the four-way directional valve body Model No. 9500 thru 9507. An instruction sheet is included in this kit.

These kits are serviced only as complete kits.

Pump Assembly

Pressure Regulator Assembly

Basic Pump Assembly

Needle Bearing Installation Specifications

When replacing the needle bearings on the drive gear of the basic pump, the dimensions shown must be:

(A) 2.4130 to 2.6670 mm (0.095 to 0.105 in)

(B) 2.4130 to 2.6670 mm (0.095 to 0.105 in)

High Pressure Pump Assembly

Bolt Tightening Sequence

Assemble in sequence shown. Lubricate under head and on threads. Tighten to a torque of 20 N·m (180 lb in).