Return to Master Table of Contents Page 20 Hydraulic System Troubleshooting, Testing and Adjustment FLOW METER AND FLOW METER KIT INSTALLATION AND TESTING Checking regulator and pump output, to assess the output balance between the front and rear pumps and to verify operating adjustment of each regulator, will require installation of a flow meter.
The After Sales Service department of the nearest local Daewoo dealer can assist you with these tests or, if you prefer carrying out your own testing, they should be able to help in putting together a hose and fitting kit (or the required dimensions and specifications for hoses and fittings) to allow you to install a flow meter downstream from the main pump assembly. Installation and Testing Procedure • Turn off the engine and operate controls to release hydraulic pressure from the accumulator. • Vent the reservoir to release all pressure from the hydraulic system. • Remove guard panels from around the main pump assembly. • Disconnect the main pump discharge output line.
Install the input flange of the flow meter on the pump end of the output line. • Cap off the unused (input) end of the pump discharge line with a blocking flange. • Bolt up a pre-measured length of hydraulic hose, between the output end of the flow meter assembly and the top of the reservoir. Use appropriate fittings and adapter flanges to guarantee a pressure tight seal. NOTE: Be sure to maintain even tightening torque on all flange fittings. Use Loctite brand "PST 545" (or an alternate manufacturer’s hydraulic system joint seal) if required, to give an airtight seal.
• An assistant - who must remain at the operator’s control station at all times - should restart the engine and run it long enough (at minimum RPM) to de-aerate the system and warm up the engine and hydraulic system to operating temperature. Record the values of all test results in three columns, comparing 1) pump pressure (from the instrument panel display) with 2) measured flow, in gallons or liters per minute, from the installed flow. meter.
The third column of test results should provide a record of engine RPM measured during each of the following tests - with the engine speed control dial set at maximum, the power mode selector at Power Mode III and the work mode selector at digging mode: • Unloaded maximum engine speed baseline test (all controls in neutral). • Front pump test - operate "travel right" lever. Record values at all specified pressures. • Rear pump test - operate "travel left" lever. Record values at all specified pressures.
Record the values for each of the three tests (neutral, travel right and travel left) at the following pump pressure levels, with travel speed control set at "high speed." Engine RPM Pressure Flow 100 kg/sq cm (1,422 psi) 135 kg/sq cm (1,930 psi) 180 kg/sq cm (2,560 psi) 240 kg/sq cm (3,413 psi) 320 kg/sq cm (4,550 psi)* *See Note, below