Section 4

GMK II Carrier Hydraulics

TRAINING INSTITUTE

TRAINING INSTITUTE

Rexroth A10V0 Hydraulic Pumps

1

2

3

Mark II Carrier (Shown)

P1, P2 and P3 Pumps are ganged together. All carriers since the Grove Acquisition Pre-Grove pumps are individually driven through a separate gear box. Pump 3, located After P1 and P2 through a common shaft.

Group Exercise : Variable Displacement Pump Operation

Instructor Hand Out Worksheet! Use the Hydraulic Pump Worksheet Describe how the the Pump De-ramps How the Pump comes on Stroke? How does this Pump use load sense?

To System

Rexroth A10V0

Flow Control Orifice

Variable Displacement Piston Pump

L

To System

Rexroth A10V0

Flow Control Orifice

14 Bar

Start -Up No Load, Pump De-ramps to 14 Bar

L

Pressure Builds

System SystemTo Demand

Rexroth A10V0

Flow Control Orifice

14 Bar

As System demands Flow Pump Ramps up

L

Group Exercise : ZF Steering Control Circuit Operation

Instructor Hand Out Worksheet! Use the ZF Steering Circuit Worksheet Describe what makes the (2) Red Lamps go off? Describe what is indicated when you see Steer Pump II Lamp Only? Describe what is indicated when you see Steer Pump I Lamp Only?

GMK ZF Steering Circuit To Steering Cylinders Left 3

4 Right

4

3

To Steering Cylinders 1

2

1

2

II

I

Panel Indicator Lamp

Panel Indicator Lamp P2 DFR

Ground Driven Pump

P 3DFR

GMK ZF Steering Circuit To Steering Cylinders Left 3

4 Right

4

3

To Steering Cylinders 1

2

1

2

II

I

P2

No Flow

DFR

Ground Driven Pump

P 3DFR

GMK ZF Steering Circuit To Steering Cylinders Left 3

4 Right

4

3

To Steering Cylinders 1

2

1

2

II

Flow Begins

I

P2 DFR

Ground Driven Pump

P3 DFR

GMK ZF Steering Circuit To Steering Cylinders Left 3

4 Right

4

3

To Steering Cylinders 1

2

1

2

II

I

Carrier Begins Moving

P2 DFR

Ground Driven Pump

P3 DFR

GMK ZF Steering Circuit To Steering Cylinders Left 3

4 Right

4

3

To Steering Cylinders 1

2

1

2

II

Carrier Steers Left

I

P2 DFR

Ground Driven Pump

P3 DFR

GMK ZF Steering Circuit To Steering Cylinders Left 3

4 Right

4

3

To Steering Cylinders 1

2

1

2

II

I

Carrier Steers Right

P2 DFR

Ground Driven Pump

P3 DFR DFR

GMK ZF Steering Circuit To Steering Cylinders Left 3

4 Right

4

3

To Steering Cylinders 1

2

1

2

II

P2 Pump Failure

I

P2 DFR

Ground Driven Pump

P3 DFR

GMK ZF Steering Circuit To Steering Cylinders Left 3

4 Right

4

3

To Steering Cylinders 1

2

1

2

II

I

P3 Pump Failure

P2 DFR

Ground Driven Pump

P3 DFR

GMK ZF Steering Circuit To Steering Cylinders Left 3

4 Right

4

3

To Steering Cylinders 1

2

1

2

II

Ground Driven Pump Failure

I

P2 DFR

Ground Driven Pump

P3 DFR

GMK ZF Steering Circuit To Steering Cylinders Left 3

4 Right

4

3

To Steering Cylinders 1

2

1

2

II

I

P2 & P3 Pump Failure

P2 DFR

Ground Driven Pump

P3 DFR

Group Exercise : ZF Steering Cylinder Operation

Instructor Hand Out Worksheet! Use the ZF Steering Cylinder Circuit Worksheet Describe what cylinders steer when in Highway? Describe what cylinders steer when in Off Road? Describe what does the Valve Bank do? Describe what do the relief valves do?

Axle #1

Axle #2

Axle #3

Axle #5

Axle #4

6Y21

6Y22

6Y31

6Y32 6Y2

P1

Independent Rear Steering Disengaged Lock Can Engaged

Axle #1

Axle #2

6Y4

6Y3

2 mm

Axle #3

Axle #5

Axle #4

6Y21

Left Turn 6Y22

6Y31

6Y32 6Y2

On Road Steering 4th Axle Fixed 5th Axle Opposite Steer

P1 6Y4

6Y3

2 mm

Axle #1

Axle #2

Axle #3

Axle #5

Axle #4

6Y21

Right Turn 6Y22

6Y31

6Y32 6Y2

On Road Steering 4th Axle Fixed 5th Axle Opposite Steer

Axle #1

Axle #2

P1 6Y4

6Y3

2 mm

Axle #3

Axle #5 Axle #4

Place in Off Road Gear

6Y21

Unlock Independent Rear Steer

6Y22

6Y31

6Y32 6Y2

Off Road Independent Rear Steering Engaged Lock Can Disengaged

P1 6Y4

6Y3

2 mm

TRAINING INSTITUTE

Rear Steering Valve Block

Rear Steer Valve Block 6Y2 and 6Y3 valves in view 6Y21, 6Y22, 6Y31 and 6Y32 attached, however in background (out of view). Located between axles 3 & 4 internal left side frame

Axle #1

Axle #2

Axle #3

Axle #5

Axle #4

6Y21

Left Rear Turn 6Y22

6Y31

6Y32 6Y2

Independent Rear Steering Engaged Lock Can Disengaged

P1 6Y4

6Y3

2 mm

Axle #1

Axle #2

Axle #3

Axle #5

Axle #4

6Y21

Right Rear Turn 6Y22

6Y31

6Y32 6Y2

Independent Rear Steering Engaged Lock Can Disengaged

P1 6Y4

6Y3

2 mm

TRAINING INSTITUTE

8Y1 Set-Up Control Valve

8Y1 Solenoid Valve Located in the engine compartment on the right side of carrier after the hydraulic pumps.

GMK 5 -Axle Cooling Circuit Slow Motor Rotation

T

Flow Through Thermostat

50 -58 C P Max 280 Bar

25 LPM

-8Y1

Minimal Flow Requirement 315 Bar

P1 DFR

GMK 5 -Axle Cooling Circuit Fast Motor Rotation

T

50 -58 C P Max 280 Bar

25 LPM

-8Y1

Thermostat Relief Closes 315 Bar

When Temp Exceeds 50o-58oC

P1 DFR

Group Exercise : Outrigger Hydraulic Operation

Instructor Hand Out Worksheet! Use the Outrigger Hydraulic Worksheet Describe what does the 8Y1 valve do? Describe what does the special symbol in the Jack Cylinder indicate? Describe what does the Relief Valve in the Jack Cylinder do?

GMK 5- Axle Outrigger Circuit Front Left Beam Extending

-9Y1

-10Y5

25 LPM - 9Y5

- 10Y1

-8Y1 Tank

315 Bar

P1 DFR Concept Drawing Only!

GMK 5- Axle Outrigger Circuit Front Left Beam Retracting

-9Y1

-10Y5

25 LPM - 9Y5

- 10Y1

-8Y1 Tank

315 Bar

P1 DFR Concept Drawing Only!

GMK 5- Axle Outrigger Circuit Front Left Jack Extending

-9Y1

-10Y5

25 LPM - 9Y5

- 10Y1

-8Y1 Tank

315 Bar

P1 DFR Concept Drawing Only!

GMK 5- Axle Outrigger Circuit Front Left Jack Retracting

-9Y1

-10Y5

25 LPM - 9Y5

- 10Y1

-8Y1 Tank

315 Bar

P1 DFR Concept Drawing Only!

Group Exercise : Outrigger Hydraulic Operation

Instructor Hand Out Worksheet! Use the Outrigger Hydraulic Worksheet How does the double holding valve operate? Describe what does the 330 bar Relief Valve do?

Jack Double Holding Valve 10Y5

Jack Cylinder

Pump Tank

10Y1

TRAINING INSTITUTE

Suspension Control Panel

Suspension Pressure Gauges Located in the Carrier Cab compartment on the right side of driver’s seat.

TRAINING INSTITUTE

Suspension Control Panel Suspension Control Switches Raises or lowers all megatrak cylinders front only, rear only, left side only or right side only.

Suspension Control Key Lock Unlocks suspension control solenoids. Permits raising and lower of suspension.

Group Exercise : Suspension Hydraulic Operation

Instructor Hand Out Worksheet! Use the Suspension Hydraulic Worksheet Describe what does the 8Y1 valve do? How does the valve (above the accumulator) energize? Describe what does the 330 bar Relief Valve do? Describe Locked vs. Unlocked Describe Raising these Cylinders? Describe Lowering these Cylinders?

Axle 2

Right Side

Axle 3

Suspension Locked 25 LPM

-8Y1

Tank

-Y04

315 Bar 330 Bar

P1

Accumulator

DFR

Accumulator and Relief Protect Circuit from Shocks

Concept Drawing Only!

Axle 2

Right Side

Axle 3

Suspension Unlocked 25 LPM

-8Y1

Tank

-Y04

315 Bar 330 Bar

P1 DFR

Accumulator

Concept Drawing Only!

Accumulator and Relief Protect Circuit from Shocks

TRAINING INSTITUTE

Lock Valve and Accumulator

Axle 2

Suspension Unlocked Struts Floating

As Cylinder is extended Oils are Shared Between Cylinders

25 LPM

-8Y1

Tank

-Y04

315 Bar 330 Bar

P1 DFR

Accumulator

Concept Drawing Only!

Right Side As Cylinder is compressed Oils are Shared Between Cylinders

Axle 3

Axle 2

Suspension Unlocked

As Cylinder is extended Rod Oil flows out

Right Side

Axle 3

As Cylinder is compressed Rod Oils flows in

25 LPM

-8Y1

Tank

-Y04 Oil is shared between Cylinders and Rods/Pistons

315 Bar 330 Bar

P1

Accumulator

DFR

Accumulator and Relief Protect Circuit from Shocks

Concept Drawing Only!

Axle 2

Suspension Raising

Right Side

Carrier rises as Cylinders are extended

Rod Side Oil is regenerated back into piston side

25 LPM

-8Y1

Tank

-Y04

315 Bar 330 Bar

P1 DFR DFR

Accumulator

Concept Drawing Only!

Axle 3

Axle 2

Suspension Lowering

Right Side

Axle 3

Carrier lowers as Cylinders drain

Rod Side fills with Oil from Piston Side

25 LPM

-8Y1

Tank

-Y04

315 Bar 330 Bar

P1 DFR

Accumulator

Concept Drawing Only!

As Rod Side is filled, Excess Oil exhausts to tank