330D, 336D and 340D Excavators Hydraulic System – Main Pump (Flow) – Test – Constant Horsepower Flow Control for Stage 2 Pump

Specification

Table 1
Main Pump (Flow) – Test (Constant Horsepower Flow Control)    
Machine Settings     Power Shift Pressure     Engine Speed    
2700 kPa (390 psi) Engine speed dial “10”
AEC switch OFF
1800 rpm    
    Measuring Points    
7000 kPa (1025 psi) 14000 kPa (2050 psi)     18000 kPa (2600 psi)     26000 kPa (3750 psi)     30000 kPa (4350 psi)    
Flow measured liter/min (US gpm)     Drive Pump                        
Idler Pump                    
Oil temperature °C (°F)                        
               
Engine speed (rpm)                        
               
Flow corrected liter/min (US gpm)     Drive Pump                        
Idler Pump                    
Specification for flow rate liter/min (US gpm)     New     272 ± 10 (72 ± 2.6)     235 ± 15 L/min (62 ± 4.0 US gpm)     208 ± 15 L/min (55 ± 4.0 US gpm)     175 ± 10 (46 ± 2.6)     160 ± 10 (42 ± 2.6)    
Service limit 252 L/min (67 US gpm)     210 L/min (55 US gpm)     183 L/min (48 US gpm)     155 L/min (41 US gpm)     140 L/min (37 US gpm)    

Illustration 1 g01625457

P-Q characteristic curve

Note: Specifications for output flow rates are based on an engine speed of 1800 rpm. To attain more accurate test results, measured flow should be corrected with the following calculation.

Table 2
Corrected flow     =     Measured flow x 1800 rpm    
measured rpm

Note: Specifications for output flow rates are based on a power shift pressure at the pump of 2700 kPa (390 psi). The output flow rate changes approximately 10 L (2.6 US gal) for each 100 kPa (14 psi) of power shift pressure in the lower range of the constant horsepower control. The output flow rate changes approximately 3 L/min (0.8 US gpm) for each 100 kPa (14 psi) of power shift pressure in the higher range of the constant horsepower control.

Note: If the output flow rate of the pump is not within the specification, disconnect the negative flow control line from the pump that is being tested and perform the test again.

Note: Flow measurements must be done only during pressure rise.

Introduction

This test measures individual pump flow at the pump. Each pump is tested individually for output flow at specified pressures. The pump that is not being tested is not under load and the pump remains at low-pressure standby.

Illustration 2 g01721640

(A) Message display

(B) Monitor

Illustration 3 g03400941

The electronic control module is located in the compartment behind the cab.

(C) Alarm lamp

(D) Electronic control module

Note: Before starting main pump flow tests, check display (A) on monitor (B) and alarm lamp (C) on electronic control module (D) for normal operation. Lamp (C) should be green. If no faults are present, perform the operational checks. Refer to Testing and Adjusting, “Operational Checks”.

Note: If the operational checks indicate that slow speed of an implement is common to the circuits of one pump, the problem is most likely in the hydraulic system. Then perform the pump flow tests. Refer to Testing and Adjusting, “Main Pump (Flow) – Test (Constant Horsepower Flow Control)”.

Note: If the operational checks indicate that slow speed of an implement is common to both pump circuits, the problem may be in the engine, the fuel, or the working altitude.

Note: Perform the following procedures before testing the main pump flow.

  • Set the pilot pressure to the specifications in Testing and Adjusting, “Relief Valve (Pilot) – Test and Adjust” for the machine.

  • Set the main relief valve to specifications. Refer to Testing and Adjusting, “Relief Valve (Main) – Test and Adjust” for the machine.

  • Calibrate the power shift pressure. Refer to Testing and Adjusting, “Calibration” for the Machine Electronic Control System.

Required Tools

Illustration 4 g01623868

Tooling (B)

198-4240 Digital Pressure Indicator Gp

Illustration 5 g02535237

Tooling (C)

Illustration 6 g03401783

Tooling (D) (Flow meter tool layout)
Table 3
Required Tools    
Tool     Item     Part
Number    		 Description     Qty    
B     198-4240     Digital Pressure Indicator Gp        
    B1     198-4234     Indicator     1    
B2 198-4238     Pressure Sensor

3447 kPa (500 psi)    

 1    
B2 198-4239     Pressure Sensor

41,368 kPa (6,000 psi)    

 2    
B3 198-4236     Extension Cable     3    
C     348-5430     Multi-Tool Gp     1    
    C1     285-0908     Multi-Tool     1    
C2 6V-2198     Cable As     1    
C3 9U-5140     Photo Pickup     1    
C4 6V-3137     Base     1    
C5 1U-6605     Reflective Tape     1    
C6 6V-3138     Extension     1    
D     D1     4C-9910     Portable hydraulic tester (flow meter)     1    
D2 6K-6307     O-Ring Seal     2    
D3 8C-9026     Adapter     2    
D4 7M-8485     O-Ring Seal     9    
D5 4C-6482     Fitting     4    
D6 4C-6481     Coupler     4    
D7 4C-8767     Coupling     4    
D8 5P-1010     Sleeve     4    
D9 5P-0201     Hose     2    
D10 1U-8303     Fitting     1    
D11 8T-4184     Bolt     4    
D12 8T-4223     Hard Washer     4    
D13 1P-5767     Half Flange     2    
D14 1U-8293     Adapter     1    
D15 1P-3704     Rectangular Seal     2    
D16 7I-7133     Blocking Cover     1    
D17 4I-6141     Adapter     1    
D18 5K-9090     O-Ring Seal     4    
D19 6V-9854     Elbow     1    
D20 6V-9840     Swivel Tee     1    
F     311-1362     Vacuum Cap     1    

ReferenceRefer to Tool Operating Manual, NEHS1087 for operating instructions for the 348-5430 Multi-Tool Gp .

Note: Use Software License Card, NETG5049 with part number 348-5430 Multi-Tool Gp .

Machine Preparation

Illustration 7 g03401368

Flow meter tool layout

Tooling (D)

(1) Swing motor

(2) Connector at swing motor

(4) Makeup line (swing motor)

(6) Negative flow control line (drive pump)

(11) Delivery line (idler pump)

(12) Delivery line (drive pump)

(13) Negative flow control line (idler pump)

(23) Drive pump

(24) Idler pump

Illustration 8 g03401834

Circuit diagram

(1) Swing motor

(2) Connector

(3) Makeup line

(5) Main control valve

(8) Pressure tap (delivery pressure for idler pump)

(9) Pressure Sensor

(11) Delivery line for idler pump

(12) Delivery line from drive pump

(16) Pressure tap (delivery pressure for drive pump)

(20) Pressure Sensor

(21) Engine

(23) Drive pump

(24) Idler pump

(50) Pressure tap (power shift pressure)

(C1) Multitach

(D1) 4C-9910 Portable Hydraulic Tester (Flow meter)

(D16) 9U-7335 Blocking Cover

(D19) Elbow

(D20) Tee

Drive Pump
NOTICE

Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting, and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.

Refer to Special Publication, NENG2500, “Dealer Service Tool Catalog” for tools and supplies suitable to collect and contain fluids on Cat products.

Dispose of all fluids according to local regulations and mandates.

Note: Perform the test for the drive pump and the test for the idler pump one at a time.

Illustration 9 g01241832

Pump compartment

(8) Pressure tap (delivery pressure for idler pump)

(12) Delivery line for drive pump

(16) Pressure tap (delivery pressure for drive pump)

(23) Drive pump

(24) Idler pump

(50) Pressure tap (power shift pressure)
  1. Position the machine on level ground.
  1. Stop the engine.
  1. Release the pressure in the hydraulic system. Refer to Testing and Adjusting, “Hydraulic System Pressure – Release”.
  1. Attach 311-1362 Vacuum Cap onto the hydraulic tank. Attach an air supply hose onto the assembly. Apply 276 to 414 kPa (40 to 60 psi). This procedure will pull a vacuum on the hydraulic system.
  1. Install the following tools in accordance with the flow meter tool layout and the circuit diagram. Refer to Illustration 7 and Illustration 8.
    1. Disconnect delivery line (12) from drive pump (23) .
    1. Install seal (D15) , half flanges (D13) , and blocking cover (D16) to the end of delivery line (12) by using bolts (D11) and washers (D12) .
    1. Assemble and install seal (D15) , adapter (D14) , seals (D4) , fitting (D10) and nipple assembly (D5) on drive pump (23) by using half flanges (D13) , bolts (D11) and washers (D12) .

      Illustration 10 g03401916

      Swing motor (top view)

      (1) Swing motor

      (2) Connector

      (4) Makeup line

      (D19) Elbow

      (D20) Tee

    1. Disconnect makeup line (4) from connector (2) at swing motor (1) .
    1. Assemble and install seals (D18) , tee (D20) , swivel elbow (D19) and coupling (D17) to connector (2) at swing motor (1) .
    1. Install seal (D18) and makeup line (4) to tee (D20) .
    1. Remove 311-1362 Vacuum Cap and install the filler plug for the hydraulic tank.
    1. Connect portable hydraulic tester (D1) and the test hoses between nipple assembly (D5) at drive pump (23) and coupling (D17) at the swing motor.
    1. Connect 3447 kPa (500 psi) pressure sensor to tap (50) for power shift pressure. Connect 41368 kPa (6000 psi) pressure sensor to tap (16) for drive pump delivery pressure.
    1. Install multitach group (C1) on engine (21) . This group is used to monitor engine speed.