Fault Phenomenon: SANY SW936 wheel loader when lifting heavy loads, pressure fails to reach standard value, load cannot be lifted.

Troubleshooting Process:
– Checked relief valve: main relief valve spring fatigued, softened, or broken.
– Checked spool: spool worn.
– Checked pressure gauge: gauge inaccurate.
– Checked pump: pump worn.

Root Cause: The pressure regulating spring of the main relief valve in the multi-way valve fatigued and deformed due to long-term high-frequency use, reducing its stiffness and lowering the opening pressure.

Required Parts: Replace main relief valve spring, readjust pressure.