OPERATIONAL PERFORMANCE TEST /System performance

Main Relief Valve Set Pressure

Summary:

The main relief pressure (set pressure of the main relief valve on the control valve) of the loader circuit is measured.

Preparation:

1. Stop the engine.

2. Push the pressure release button on the hydraulic oil tank to release air pressure.

3. Install the oil pressure gauge to the outlet port for the tilt cylinder.

4. Start the engine. Check the pressure gauge connection for any oil leaks.

5. Maintain the hydraulic oil temperature at 50 ± 5 ℃ (122 ± 9°F).

Measurement:

11.Accelerator Pedal:Full Stroke(Engine at Fast Idle),Parking Brake Switch:ON,FNR Shift Lever:N(Neutral)

2. Slowly operate each control lever of the lift arm and bucket. Move each cylinder to the stroke end to relieve each function. Measure the pressure while each function is relieving.

3. Repeat each measurement three times and calculate the average value.

Evaluation:

Refer to the Performance Standard Table

NOTE:

If the measured relief pressures in all circuits are lower than specification, the probable cause may be a reduction in the set pressure of the main relief valve. If the measured relief pressure is different in only a particular circuit, the probable cause is other than the main relief valve.

Adjustment:

After loosening the lock nut, turn the adjusting screw.

1. Loosen the lock nut.

2. Turn the adjusting screw.

Tightening (turn right): Oil pressure increase Loosen (turn left): Oil pressure decrease

3. Tighten the lock nut.

4. Recheck the set pressure after adjustment.