Dynapac CA2500D vibration fault traced to collapsing suction hose
A contractor's Dynapac CA2500D roller lost vibration consistency over two weeks, requiring six or more passes instead of four. A technician found a delaminated suction hose restricting oil flow, plus internal wear in the vibration motor.
A highway contractor reported that a Dynapac CA2500D single-drum roller had shown weakening, uneven drum vibration across two weeks. The machine needed six or more passes to reach the dry density previously achieved in four, and the surface showed drum bouncing.
A technician measured inlet pressure at the vibration motor at 22 MPa, against a specification of roughly 28 MPa. Case-drain flow was higher than expected, pointing to internal leakage past the motor's pistons.
Before replacing the motor, the technician checked the vibration pump's suction line. The rubber hose's inner liner had delaminated and was collapsing under operating vacuum, limiting oil flow to the pump. The resulting low-flow, low-pressure operation was linked to accelerated wear inside the vibration motor.
The repair replaced the suction hose and the vibration motor, flushed the circuit, and renewed the hydraulic oil and return filter. Inlet pressure then read 28 MPa, and a loaded compaction test returned four-pass dry density. Suction hose inspection was added to the 500-hour service checklist.
For equipment buyers, ask whether a used CA2500D's vibration circuit has documented pressure and case-drain checks, and whether suction hoses were inspected on schedule. Request records of any vibration motor replacement and confirm the correct hose specification for suction service.