- Mini Hydraulic Excavator:
- 301.6C (S/N: JBB1-UP)
- 301.8C (S/N: JSB1-UP)
- 302.5C (S/N: GBB1-UP)
Description of Change: The Testing and Adjusting procedure for mini hydraulic excavators has changed. The previous procedure contained incorrect pressure specifications for the setting of the swing relief valve.
Adaptable To: The previous Testing and Adjusting procedure contained incorrect pressure settings for the swing motor relief valve. The previously listed setting is based on a flow rate across the relief valve. The flow rate across the relief valve was 11 liters per minute with no tank or return line back pressure. The valves are set at the supplier's facility by using this oil flow rate.
The specifications have been changed in line with Caterpillars specifications for product certifications. These specifications account for the higher oil flow rate over the relief valve. These specifications also account for the increased back pressure in the oil return lines. The method of testing the relief setting has not been changed.
| Relief Valve Setting | |
| Old | New |
| 13,400 ± 2000 kPa | 17,720 ± 2000 kPa |