938G Wheel Loader and IT38G Integrated Toolcarrier Braking System Caterpillar

If the oil in the braking system becomes contaminated, premature component failure could result. Contaminated oil can also contribute to overheating. Use the following procedure to sample the oil in the braking system.

1. Start the engine and run the engine at high rpm.

2. Actuate all cylinders through a minimum of ten full cycles.

3. Actuate the service brakes in order to cycle the charging system for the brake accumulators.

4. Lower the bucket and/or attachments to the ground and stop the engine.

5. Move all control levers and the brake pedals through all positions in order to release the pressure in the hydraulic system.

6. Slowly loosen the hydraulic tank filler cap in order to release any remaining pressure. Then, remove the filler cap completely.

7. Connect a hose assembly to the connection fitting in the pump port. Put the other end of the hose into the hydraulic tank filler opening. Make sure that all of the hydraulic controls are in the HOLD position.

8. Start the engine and allow the engine to run at low idle.

   Note: Do not operate the hydraulic controls.

9. Draw a 50 mL (1.7 fl oz) oil sample through the tee in the hose assembly. The level of contaminants must be lower than the values in the following table.
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   Table 1

   Hydraulic Oil Contamination
   Particle Size (Microns)	Maximum Number of Particles
   10 to 20	48000
   21 to 50	2580
   51 to 100	150
   100 or more	20