308C CR Excavator Hydraulic System – Travel Motor – Test – Measurement of Case Drain Oil

Table 1
Required Tools    
Part Number     Description     Qty    
FT-2547     Track block assembly     1    
6V-9508     Face Seal Plug     1    
6V-8397     O-Ring Seal     1    
    Remote drain hose with an inside diameter of
17 mm (.68 inch)    
    Container for measuring     1    


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, “Caterpillar Tools and Shop Products Guide” for tools and supplies suitable to collect and contain fluids on Caterpillar products.

Dispose of all fluids according to local regulations and mandates.

  1. Stop the engine.
  1. Release the pressure in the hydraulic system. Refer to Testing and Adjusting, “Hydraulic System Pressure – Release”.

    Illustration 1 g00729025

    Sprocket (left track)

    (1) Sprocket

    (2) FT-2547 Track block assembly

  1. Place track block assembly (2) in sprocket (1) in order to block forward left travel. Refer to Illustration 1.

    Illustration 2 g00728610

    Travel motor

    (3) 6V-9508 Face seal plug

    (4) 6V-8397 O-Ring seal

    (5) Case drain hose

    (6) Connector

    (7) Remote drain hose

    (8) Container for measuring

  1. Disconnect case drain hose (5) from connector (6). Install plug (3) and seal (4) in the open end of case drain hose (5) .
  1. Connect one end of remote drain hose (7) to connector (6). Place the other end of remote drain hose into the container (8) in order to measure the case drain oil.
  1. Start the engine.
  1. Place the machine controls at the following settings: engine speed dial “10” and Low idle switch OFF. Refer to Testing and Adjusting, “Engine Performance – Test” for engine rpm settings.
  1. Place the hydraulic activation control lever in the UNLOCKED position.
  1. Increase the hydraulic oil temperature to 55° ± 5°C (131° ± 9°F).
  1. Move the left travel lever forward fully for one minute.
  1. Measure the amount of case drain oil.
  1. Remove track block assembly (2) from sprocket (1) .
  1. Move the left travel lever in order to reposition the travel motor.
  1. Place track block assembly (2) in sprocket (1) in order to block forward left travel.
  1. Repeat Steps 10 through 14 in order to obtain three measurements of case drain oil.

The following values specify the maximum acceptable flow of case drain oil when the main relief valve pressure is set at 31400 ± 490 kPa (4550 ± 72 psi).

New travel motor … 5 L/min (1.3 US gpm)
Rebuilt travel motor … 10 L/min (2.6 US gpm)