330D, 336D and 340D Excavators Hydraulic System – Pump Control (Negative Flow) – Adjust

Introduction

Adjust the negative flow control if the flow test results differ greatly from the specification.

Adjustment Procedure

Illustration 1 g02100279

Pump Compartment

(1) Adjustment screw

(2) Locknut

(3) Adjustment screw

(4) Locknut

Note: Use the same procedure for both pumps. Use locknut (1) and adjustment screw (2) to adjust the drive pump. Use locknut (4) and adjustment screw (3) to adjust the idler pump.

  1. Loosen locknut (2) .
  1. Turn adjustment screw (1) until the negative flow rate is adjusted to the correct specification.

    Note: A clockwise adjustment of adjustment screw (1) and adjustment screw (3) increases the flow rate. A counterclockwise adjustment decreases the flow rate.

    Note: A quarter turn of adjustment screw (1) will change the flow rate approximately 17.9 L/min (4.7 US gpm) which is approximately 100 kPa (15 psi).

  1. Tighten locknut (2) to a torque of 16 N·m (12 lb ft).
  1. Adjust the idler pump. Use locknut (4) and adjustment screw (3) to adjust the idler pump.