Pascal

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Oil is the most commonly used medium because it serves as a lubricant and is practically ... two arrows heads, meaning this pump is capable of pumping oil in two directions ...

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Pascal

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Foundations Hydraulic Pumps Axial Piston Pump Gear Pump Motors Check Valve Reservoirs Conditioners Pascal’s Law Application Principles Hydraulic Valve JIC Build With JIC’s (Left Click Selection Box) Hydraulic Cylinder Principles Cylinder Leakage Test Relief Valve Lines and Connections Pressure Differential Relief Hydraulic Fluid Least Resistance Open vs Closed JIC Liquids Have no Shape of their own Liquids are Practically Incompressible Liquids under pressure follow what path? Path of least Resistance Path of Least Resistance 10 lbs

Slide 7:Pascal’s Law

Pressure Exerted on a Confined Fluid is Transmitted Undiminished in All Directions and Acts With Equal Force on Equal Areas and at Right Angles to Them. 7 Imperial Metric --Hydraulics is a means of power transmission --Oil is the most commonly used medium because it serves as a lubricant and is practically non-compressible (it will compress approximately 1/2 of a 1 percent per 1000 PSI). --Weight of oil varies with viscosity, but averages between 55 to 55 lbs per cubic foot. (at 100 degrees F). NOTE: A cubic foot of oil is 1728 Cu.In (12x12x12). A gallon is 231 Cu.In., so a Cubic Foot of oil is equivalent to 7.48 Gallons. --A liquid is pushed, NOT DRAWN, into a pump. Atmospheric pressure equals 14.7 PSI at sea level. --Oil takes the course (path) of least resistance. FORMULAS; 1. H.P. = GPM x Pressure x .000583 -or- H.P. = GPM x PSI / 1714 2. One H.P. = 33000 ft./lbs. per minute (33000 lbs raised 1 ft in 1 minute) One H.P. = 746 Watts, One H.P. = 42.4 BTU per minute 3. Required Area of a transmission line; Area = GPM x .3208 / velocity (ft./sec) -or- Velocity (ft./sec) = GPM / 3.117 x Area Pascal’s Law, named after Blaise Pascal (French 1623-1662)--Hydraulics is a means of power transmission --Oil is the most commonly used medium because it serves as a lubricant and is practically non-compressible (it will compress approximately 1/2 of a 1 percent per 1000 PSI). --Weight of oil varies with viscosity, but averages between 55 to 55 lbs per cubic foot. (at 100 degrees F). NOTE: A cubic foot of oil is 1728 Cu.In (12x12x12). A gallon is 231 Cu.In., so a Cubic Foot of oil is equivalent to 7.48 Gallons. --A liquid is pushed, NOT DRAWN, into a pump. Atmospheric pressure equals 14.7 PSI at sea level. --Oil takes the course (path) of least resistance. FORMULAS; 1. H.P. = GPM x Pressure x .000583 -or- H.P. = GPM x PSI / 1714 2. One H.P. = 33000 ft./lbs. per minute (33000 lbs raised 1 ft in 1 minute) One H.P. = 746 Watts, One H.P. = 42.4 BTU per minute 3. Required Area of a transmission line; Area = GPM x .3208 / velocity (ft./sec) -or- Velocity (ft./sec) = GPM / 3.117 x Area Pascal’s Law, named after Blaise Pascal (French 1623-1662)

This slide illustrates one of the basic principles of hydraulics; LIQUIDS TRANSMIT APPLIED PRESSURE EQUALLY IN ALL DIRECTIONS. BUILDS: 1. When a 1 lb (.45kg) force is applied to this handle and the area of the piston is 1sq in (.65cm2), with the confined fluid, what PSI (kpa) pressure will be produced? (1psi (6.9kpa)) Note that this pressure is exerted in every direction. 2. With a 10 sq in (6.5cm2) piston, how much weight will this system lift? This principle is what allows us to multiple our work efforts. With 1 lb (.45kg) of down pressure, we are able to lift 10 lbs (4.5kg). Pressure is caused by a resistance to flow, in this case the 10 lb (4.5kg) weight. Point out that resistance to flow is what causes pressure. In this example, if there were a 100 lb (45kg) weight on the right side (in place of the 10 lb (4.5kg) weight), how much pressure would be required to lift it. (10 PSI (69kpa)). --Hydraulics is a means of power transmission --Oil is the most commonly used medium because it serves as a lubricant and is practically non-compressible (it will compress approximately 1/2 of a 1 percent per 1000 PSI). --Weight of oil varies with viscosity, but averages between 55 to 55 lbs per cubic foot. (at 100 degrees F). NOTE: A cubic foot of oil is 1728 Cu.In (12x12x12). A gallon is 231 Cu.In., so a Cubic Foot of oil is equivalent to 7.48 Gallons. --A liquid is pushed, NOT DRAWN, into a pump. Atmospheric pressure equals 14.7 PSI at sea level. --Oil takes the course (path) of least resistance. FORMULAS; 1. H.P. = GPM x Pressure x .000583 -or- H.P. = GPM x PSI / 1714 2. One H.P. = 33000 ft./lbs. per minute (33000 lbs raised 1 ft in 1 minute) One H.P. = 746 Watts, One H.P. = 42.4 BTU per minute 3. Required Area of a transmission line; Area = GPM x .3208 / velocity (ft./sec) -or- Velocity (ft./sec) = GPM / 3.117 x Area Pascal’s Law, named after Blaise Pascal (French 1623-1662) IMPERIAL --Hydraulics is a means of transmitting power. --Oil is the most commonly used medium because it serves as a lubricant and is practically non-compressible (it will compress approximately 1/2 of 1 percent per 690 kpa). --Weight of oil varies with viscosity, but averages between 23 to 25 kg per cubic foot. (at 100 degrees F). NOTE: A cubic foot of oil is 1728 Cu.In (12x12x12). A gallon is 231 Cu.In., so a Cubic Foot of oil is equivalent to 7.48 Gallons. --Liquid is pushed (by Atmospheric Pressure), NOT DRAWN, into a pump. Atmospheric pressure equals 14.7 PSI at sea level. --Oil takes the path (line) of least resistance. FORMULAS; 1. H.P. = GPM x Pressure x .000583 -or- H.P. = GPM x PSI / 1714 2. One H.P. = 33000 ft./lbs. per minute (33000 lbs raised 1 ft in 1 minute) One H.P. = 746 Watts, One H.P. = 42.4 BTU per minute 3. Required Area of a transmission line; Area = GPM x .3208 / velocity (ft./sec) -or- Velocity (ft./sec) = GPM / 3.117 x Area Pascal’s Law, named after Blaise Pascal (French 1623-1662) METRIC

Slide 11:Application Principles

10 sq in (6.5cm2) Piston Area 10 lbs (4.5kg) 11 This slide illustrates one of the basic principles of hydraulics; LIQUIDS TRANSMIT APPLIED PRESSURE EQUALLY IN ALL DIRECTIONS. BUILDS: 1. When a one pound force is applied to this handle and the area of the piston is one square inch, with the confined fluid, what PSI pressure will be produced? Note that this pressure is exerted in every direction 2. With a 10 square in piston, how much weight will this system lift? This principle is what allows us to multiple our work efforts. With one lb of down pressure, we are able to lift 10 lbs. --Pressure is caused by a resistance to flow. In this case the 10 lb weight. Point out that resistance to flow is what causes pressure. In this example, if there were a 100 lb weight on the right side (in place of the 10 lb weight), how much pressure would be required to lift it. (10 PSI).This slide illustrates one of the basic principles of hydraulics; LIQUIDS TRANSMIT APPLIED PRESSURE EQUALLY IN ALL DIRECTIONS. BUILDS: 1. When a one pound force is applied to this handle and the area of the piston is one square inch, with the confined fluid, what PSI pressure will be produced? Note that this pressure is exerted in every direction 2. With a 10 square in piston, how much weight will this system lift? This principle is what allows us to multiple our work efforts. With one lb of down pressure, we are able to lift 10 lbs. --Pressure is caused by a resistance to flow. In this case the 10 lb weight. Point out that resistance to flow is what causes pressure. In this example, if there were a 100 lb weight on the right side (in place of the 10 lb weight), how much pressure would be required to lift it. (10 PSI).

THE TWO MAIN TYPES OF PUMPS: 1. With a positive displacement pump, with each revolution, a specific amount of fluid is pumped somewhere. 2. The non-positive pump can rotate all day and not necessarily cause fluid to flow. Thus the positive displacement pump is used in applications that require higher pressures and the non-positive displacement pumps are used in applications that require high volumes (flow rates).

Slide 13:Pump Types

Positive Displacement -With each revolution a specific amount is pumped somewhere Low Volume, High Pressure Non Positive (IE: Water Pump) High Volume, Low Pressure 13 The two main types of Pumps 1. With a positive displacement pump, with each revolution, a specific amount of fluid is pumped somewhere. 2. The non-positive pump can rotate all day and not necessarily cause fluid to flow … Thus the positive displacement pump is used in applications that require higher pressures and the non-positive displacement pumps are used in applications that require high volumes (flow rates) The two main types of Pumps 1. With a positive displacement pump, with each revolution, a specific amount of fluid is pumped somewhere. 2. The non-positive pump can rotate all day and not necessarily cause fluid to flow … Thus the positive displacement pump is used in applications that require higher pressures and the non-positive displacement pumps are used in applications that require high volumes (flow rates)

Slide 14:JIC Symbols

Joint Industry Council Symbolic Drawings used in Schematics to Represent Components.

J I C Symbols Joint Industrial Council 2139 Wisconsin Ave, NW Washington, DC 20007 This organization was founded in 1965. JIC standards replaced those written by the Joint Industrial Conference (mostly auto manufacturing) BUILDS 1. Circle, the major components in a JIC schematic are circles. For a pump with start with a circle. 2. Then we add an arrow head. The arrow pointing out of the circle signifies the direction of the fluid flow. OUT, indicating a pump 3. Continue to build showing two arrows heads, meaning this pump is capable of pumping oil in two directions 4. The arrow signifies that this pump is capable of varying the amount of flow, so it is a variable displacement pump.

Slide 16:Pumps (JIC Symbols)

Constant Displacement Single Direction Bi-Directional, Variable Displacement 16 Pumps convert mechanical power into hydraulic force J I C Symbols Joint Industrial Council 2139 Wisconsin Ave, NW Washington, DC 20007 This organization was founded in 1965. JIC standards replaced those written by the Joint Industrial Conference (mostly auto manufacturing) BUILDS 1. Circle, the major components in a JIC schematic are circles. For a pump with start with a circle. 2. Then we add an arrow head. The arrow pointing out of the circle signifies the direction of the fluid flow. OUT, indicating a pump 3. Continue to build showing two arrows heads, meaning this pump is capable of pumping oil in two directions 4. The arrow signifies that this pump is capable of varying the amount of flow, so it is a variable displacement pump. Lastly, ask the students based on the symbols shown, what type of pump is this? Then ask, what configuration of pump is capable of variable displacement and pumping in two directions?J I C Symbols Joint Industrial Council 2139 Wisconsin Ave, NW Washington, DC 20007This organization was founded in 1965. JIC standards replaced those written by the Joint Industrial Conference (mostly auto manufacturing) BUILDS1. Circle, the major components in a JIC schematic are circles. For a pump with start with a circle. 2. Then we add an arrow head. The arrow pointing out of the circle signifies the direction of the fluid flow. OUT, indicating a pump 3. Continue to build showing two arrows heads, meaning this pump is capable of pumping oil in two directions 4. The arrow signifies that this pump is capable of varying the amount of flow, so it is a variable displacement pump. Lastly, ask the students based on the symbols shown, what type of pump is this? Then ask, what configuration of pump is capable of variable displacement and pumping in two directions?

“Heavy Duty” applications that require variable displacement bi-directional pumps, typically use axial piston pumps. POINT OUT THE: 1. Rotating group 2. Swash plate 3. Pistons

Slide 18:Axial Piston Pump

Neutral Position Vertical Swashplate Rotating Group Typically 9 Pistons Swash Plate 18 Engine Shaft Pumps Pressure Oil Each Piston “Heavy Duty” applications that require variable displacement bi-directional pumps, typically use axial piston pumps. Point out the: 1. Rotating group 2. Swash plate 3. Pistons “Heavy Duty” applications that require variable displacement bi-directional pumps, typically use axial piston pumps. Point out the: 1. Rotating group 2. Swash plate 3. Pistons

SWASHPLATE ANGLE, FORWARD POSITION: 1. As the hydro linkage is slowly moved forward (swashplate angle changes) the vehicle starts to move forward. 2. The movement of the swashplate controls the direction of the motor rotation. 3. When the swashplate is moved further forward (swashplate angle increases), the piston assemblies start to travel further, generating more flow, more oil is being pumped and the speed of the vehicle is increased. 4. Flow rate is determined by length and frequency of strokes. When full swashplate travel is reached (maximum swashplate angle), the maximum volume of oil is being discharged from the pump, then the speed of the motors are at maximum.

Slide 20:Axial Piston Pump

Forward Position Angled Swashplate Rotating Group Typically 9 Pistons 20 Pressure Charge Oil Swashplate Angle Forward Position As the hydro linkage is slowly moved forward the vehicle starts a forward movement. The movement of the swashplate controls the direction of the motor rotation. When the swashplate is moved further, the piston assemblies start to reciprocate further, generating more flow, more oil is being pumped and the speed of the vehicle is increased. Flow rate is determined by length of and frequency of strokes (RPM). When full swashplate angle is reached, the maximum volume of oil is being discharged from the pump the speed of the motors are at the greatest. Swashplate Angle Forward Position As the hydro linkage is slowly moved forward the vehicle starts a forward movement. The movement of the swashplate controls the direction of the motor rotation. When the swashplate is moved further, the piston assemblies start to reciprocate further, generating more flow, more oil is being pumped and the speed of the vehicle is increased. Flow rate is determined by length of and frequency of strokes (RPM). When full swashplate angle is reached, the maximum volume of oil is being discharged from the pump the speed of the motors are at the greatest.

Slide 21:Axial Piston Pump

Reverse Position Angled Swashplate Rotating Group Typically 9 Pistons 21 Charge Pressure In the reverse position, the pump shaft still rotates in the same direction, but the discharge of oil from the pump is reversed, thus reversing the motor rotation.In the reverse position, the pump shaft still rotates in the same direction, but the discharge of oil from the pump is reversed, thus reversing the motor rotation.

Before going back into JIC symbols, lets show another very popular type of pump or motor. 1. What clues might we have to determine whether this device is a pump or a motor? NOTE: Typically, a pump will have a larger INLET opening. 2. If this were a Pump and with the pump turning in the direction illustrated by the arrows, which side is the inlet and which side is the outlet? Build shows inlet and outlet.

Slide 23:Gear Pump or Motor

23 Before going back into JIC symbols, lets show another very popular type of pump or motor. 1. What clues might we have to determine whether this device is a pump or a motor. NOTE: Typically, a pump will have a larger INLET opening. 2. If this were a Pump and with the pump turning in the direction illustrated by the arrows, which side is the inlet and which side is the outlet. Build shows inlet and outletBefore going back into JIC symbols, lets show another very popular type of pump or motor. 1. What clues might we have to determine whether this device is a pump or a motor. NOTE: Typically, a pump will have a larger INLET opening. 2. If this were a Pump and with the pump turning in the direction illustrated by the arrows, which side is the inlet and which side is the outlet. Build shows inlet and outlet

BUILDS: 1. Circle; as mentioned some of the major components in the hydraulic schematic are shown as circles. 2. Add an arrow head, but note how this arrow head differs from the pump shown earlier .. it points “IN”. 3. Second circle with arrowhead. This arrowhead comes down from the top. Does this signify any difference? (NO). 4. Second arrowhead. What type of motor is this? (bi-directional)

Slide 25:Motors (JIC Symbols)

Single Direction Bi-Directional 25 Motors converts hydraulic force into mechanical power BUILDS 1. Circle, as mentioned some of the major components in the hydraulic schematic are circles 2. Add an arrow head, but note how this arrow head differs from the pump shown earlier .. it point “IN” 3. Second circle with arrowhead. This arrowhead comes down from the top. Does this signify any difference? NO. 4. Second arrowhead 5. What type of motor is this, bi-directional Motors used in turf equipment are typically fixed displacement type delivering a constant output torque for a given pressure throughout the speed range of the motor.BUILDS 1. Circle, as mentioned some of the major components in the hydraulic schematic are circles 2. Add an arrow head, but note how this arrow head differs from the pump shown earlier .. it point “IN” 3. Second circle with arrowhead. This arrowhead comes down from the top. Does this signify any difference? NO. 4. Second arrowhead 5. What type of motor is this, bi-directional Motors used in turf equipment are typically fixed displacement type delivering a constant output torque for a given pressure throughout the speed range of the motor.

Slide 26:Reservoirs

1. Vented 2. Pressurized 3. Return Above Fluid Level 4. Return Below Fluid Level 26

Slide 27:Lines and Connections

27 Standard pipe ID is larger than nominal size. Steel and Copper tubing size indicates the OUTSIDE diameter.Standard pipe ID is larger than nominal size. Steel and Copper tubing size indicates the OUTSIDE diameter.

Slide 28:Check Valve

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Relief Valves Protects the Pump and Lines from excessive pressure Returns fluid back to the reservoir

Slide 30:Relief Valve

30 Supply Pilot supply Return to Reservoir

Slide 31:Pressure Differential Valve

31 Supply Senses the DIFFERENCE in Pressure

Slide 32:Manual On/Off Valve

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Slide 33:Fluid Conditioners

Filter Oil Cooler 33

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Slide 34:Filters

Micron 1 Millionth of a Meter or 1 Thousandth of a Millimeter

Types of Hydraulic Systems Open Center Closed Center The control valve that regulates the flow from the pump determines if system is open or closed. Do not confuse Hydraulics with the “Closed Loop” of the Power Train. (Hydro) 36

Slide 36:Hydraulic Valve JIC

Closed Center Hydraulics Open Center Flow in Neutral Open Center Valve Hydraulic flow continually moves through the system because the hydraulic pump is constantly pumping fluid. The valve is open to return in neutral to allow the fluid to circulate back to the reservoir. Oil is drawn out of the reservoir because atmospheric pressure (14.7 psi) pushes it through the lines into the pump.Open Center Valve Hydraulic flow continually moves through the system because the hydraulic pump is constantly pumping fluid. The valve is open to return in neutral to allow the fluid to circulate back to the reservoir. Oil is drawn out of the reservoir because atmospheric pressure (14.7 psi) pushes it through the lines into the pump.

OPEN CENTER VALVE: 1. Hydraulic flow continually moves through the system. 2. The hydraulic pump is constantly pumping fluid. 3. The control valve is open to return in neutral to allow the fluid to circulate. Extend 38

Slide 38:Hydraulic Valve JIC

Retract 39

Slide 39:Hydraulic Valve JIC

Neutral Again 40

Slide 40:Hydraulic Valve JIC

Let’s examine what happens when a cylinder is extended. Pressure oil is routed to the piston end. Oil from the rod end is allowed to return to the reservoir.

Slide 42:Lift Cylinder

Extend Let’s examine what happens when a cylinder is extended. Pressure oil is routed to the piston end. Oil from the rod end is allowed to return to the reservoir. Let’s examine what happens when a cylinder is extended. Pressure oil is routed to the piston end. Oil from the rod end is allowed to return to the reservoir.

When cylinders “leak down” over a period of time, it is commonly believed that the cylinder piston “packings” (O-ring seals) are the cause of the problem. This IS NOT TRUE!! So where does the hydraulic oil go?

Slide 44:Lift Cylinder

Leak Down Where Does the Oil Go?? When cylinders “leak down” over a period of time, it is commonly believed that the cylinder piston “packings” (O-ring seals) are the cause of the problem. This IS NOT TRUE!! So where does the hydraulic oil go? When cylinders “leak down” over a period of time, it is commonly believed that the cylinder piston “packings” (O-ring seals) are the cause of the problem. This IS NOT TRUE!! So where does the hydraulic oil go?

This illustration goes beyond the practical but makes the point. Because of the volume of oil trapped in the cylinder, the rod CANNOT retract any further unless the trapped oil is allowed to escape somewhere. In this case and always with cylinders that leak down by retracting, the control valve is leaking allowing the oil out of the cylinder. Remember, this rule applies only when the cylinder rod retracts (oil leaking from the piston end to the rod end and out through the control valve). Oil can leak from the rod side to the piston side (allowing the rod to extend) because the rod side with less volume of oil can leak into the piston side with a greater area.

Slide 46:Lift Cylinder

Is it Possible for This Rod to Retract Even With the Piston Removed?? This illustration goes beyond the practical but makes the point. Because of the volume of oil trapped in the cylinder, the rod CANNOT retract any further unless the trapped oil is allowed to escape somewhere. In this case and always with cylinders that leak down by retracting, the control valve is leaking allowing the oil out of the cylinder. Remember, this rule applies only when the cylinder rod retracts (oil leaking from the piston end to the rod end and out through the control valve). Oil can leak from the rod side to the piston side (allowing the rod to extend) because the rod side with less volume of oil can leak into the piston side with a greater area. This illustration goes beyond the practical but makes the point. Because of the volume of oil trapped in the cylinder, the rod CANNOT retract any further unless the trapped oil is allowed to escape somewhere. In this case and always with cylinders that leak down by retracting, the control valve is leaking allowing the oil out of the cylinder. Remember, this rule applies only when the cylinder rod retracts (oil leaking from the piston end to the rod end and out through the control valve). Oil can leak from the rod side to the piston side (allowing the rod to extend) because the rod side with less volume of oil can leak into the piston side with a greater area.

Slide 47:Cylinder Hose Failures

Effects On Line Pressure When a Cylinder Piston Packing is Leaking 3” Diameter Piston 1.5 x 1.5 x 3.1416 = 7.07 sq.in. Results in 2122 PSI 1.5” Diameter Rod .75 x .75 x 3.1416 = 1.77 sq.in. Results in 8475 PSI 15000 lbs of Down Force This illustration goes beyond the practical but makes the point. Because of the volume of oil trapped in the cylinder, the rod CANNOT retract any further unless the trapped oil is allowed to escape somewhere. In this case and always with cylinders that leak down by retracting, the control valve is leaking allowing the oil out of the cylinder. Remember, this rule applies only when the cylinder rod retracts (oil leaking from the piston end to the rod end and out through the control valve). Oil can leak from the rod side to the piston side (allowing the rod to extend) because the rod side with less volume of oil can leak into the piston side with a greater area. This illustration goes beyond the practical but makes the point. Because of the volume of oil trapped in the cylinder, the rod CANNOT retract any further unless the trapped oil is allowed to escape somewhere. In this case and always with cylinders that leak down by retracting, the control valve is leaking allowing the oil out of the cylinder. Remember, this rule applies only when the cylinder rod retracts (oil leaking from the piston end to the rod end and out through the control valve). Oil can leak from the rod side to the piston side (allowing the rod to extend) because the rod side with less volume of oil can leak into the piston side with a greater area.

To test a cylinder for internal leakage (past the piston seals), remove the cylinder pin from the rod (what ever the cylinder works on will have to be supported). Either extend or retract the rod completely. Then remove the oil line closest to the cylinder’s internal piston. Connect a hydraulic hose to the cylinder where the line was removed. Place the other end of the hydraulic hose in a clean bucket. Pressurize the opposite side of the cylinder with hydraulic oil. Measure leakage into the bucket. If excessive leakage is observed into the bucket, replace cylinder piston seals. NOTE: On some systems, such as the John Deere light weight fairway mowers, the line returning the lift valve will need to be capped to prevent return oil from flowing out the line. Retract 49

Slide 49:Hydraulic Cylinder Leakage Test

Depending on the System, You May Have to Cap This Line To Prevent Return Oil From Leaking Out To test a cylinder for internal leakage (past the piston seals), remove the cylinder pin from the rod (what ever the cylinder works on will have to be supported). Either extend or retract the rod completely. Then remove the oil line closest to the cylinder’s internal piston. Connect a hydraulic hose to the cylinder where the line was removed. Place the other end of the hydraulic hose in a clean bucket. Pressurize the opposite side of the cylinder with hydraulic oil. Measure leakage into the bucket. If excessive leakage is observed into the bucket, replace cylinder piston seals. NOTE: On some systems, such as the John Deere light weight fairway mowers, the line returning the lift valve will need to be capped to prevent return oil from flowing out the line.To test a cylinder for internal leakage (past the piston seals), remove the cylinder pin from the rod (what ever the cylinder works on will have to be supported). Either extend or retract the rod completely. Then remove the oil line closest to the cylinder’s internal piston. Connect a hydraulic hose to the cylinder where the line was removed. Place the other end of the hydraulic hose in a clean bucket. Pressurize the opposite side of the cylinder with hydraulic oil. Measure leakage into the bucket. If excessive leakage is observed into the bucket, replace cylinder piston seals. NOTE: On some systems, such as the John Deere light weight fairway mowers, the line returning the lift valve will need to be capped to prevent return oil from flowing out the line.

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Slide 50:JIC Symbols

Would This Hydraulic Drive System Work? Hydraulic Drive Does NOT Provide Dynamic Braking Build the System Yes, In one direction

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Slide 51:JIC Symbols

PM Closed Loop Hydrostatic Transmission Hill Simulation

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Slide 52:JIC Symbols

PM Closed Loop Hydrostatic Transmission Hill Simulation

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Slide 53:JIC Symbols

PM Oil Cooler Build the System Oil Filter Inlet Check Inlet Check

Both the Oil Cooler Bypass and Oil Filter Bypass are “Differential Relief Valves” which have the capability of comparing pressures on the inlet side and the pressure on the outlet side; On the 3365 WARM, these reliefs open: 1. Oil cooler bypass will open with a differential of 80-130 PSI 2. Filter bypass will open with a differential of 20-30 PSI Leak off lines are NOT shown, but are required to provide; 1. Lubrication 2. Cooling 3. Cleaning 55

Slide 55:JIC Symbols

Build the System PM Oil Cooler Oil Filter Charge Relief Valve Oil Cooler Bypass Valve Filter Bypass Valve

This slide shows normal oil flow; 1. Hydro turns providing oil flow to motors. 2. Motors turn, some oil is lost to case drain 3. Charge pump provides oil flow through; Cooler Filter Inlet Check Valves 57

Slide 57:JIC Symbols

Hydrostatic Transmission Components Oil Cooler Oil Filter Charge Relief Valve Oil Cooler Bypass Valve Filter Bypass Valve Both the Oil Cooler Bypass and Oil Filter Bypass are “Differential Relief Valves” which have the capability of comparing pressures on the inlet side and the pressure on the outlet side; On the 3365 WARM, these reliefs open: 1. Oil cooler bypass will open with a differential of 80-130 PSI 2. Filter bypass will open with a differential of 20-30 PSI Leak off lines are NOT shown, but are required to provide; 1. Lubrication 2. Cooling 3. CleaningBoth the Oil Cooler Bypass and Oil Filter Bypass are “Differential Relief Valves” which have the capability of comparing pressures on the inlet side and the pressure on the outlet side;On the 3365 WARM, these reliefs open: 1. Oil cooler bypass will open with a differential of 80-130 PSI 2. Filter bypass will open with a differential of 20-30 PSI Leak off lines are NOT shown, but are required to provide; 1. Lubrication 2. Cooling 3. Cleaning

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