The reasons for excavators to hold the car are:

The engine power does not match the hydraulic pump power.

The engine has insufficient intake.

Braking caused by heavy objects.

Hydraulic pump or distribution valve leakage, resulting in pump power greater than the engine power.

Regulator wear, pump valve group pressure flow is too large, pump internal components wear and other reasons.

Diesel labeling error, may be cold weather diesel viscosity, insufficient oil supply.

The voltage of the PRV solenoid valve is insufficient.

The valve clearance of the engine is too large or too small.

Pump pressure is incorrect.

Insufficient engine speed or load power.