Hyundai HL955 Manual page 362

(4) (4) Maintenance of the accumulator Maintenance of the accumulator
No special maintenance beyond the legal requirements is necessary.
The accumulator should be checked annually. It should be replaced if the initial gas pressure has
fallen by more than 30% (please refer to Performance testing and checking of the accumulator).
(5) (5) Disposal of the accumulator Disposal of the accumulator
Before the accumulator is scrapped, its gas filling pressure must be reduced. For this purpose,
drill a hole through gas chamber (B) using a drill approx. 3mm in diameter. The gas chamber is
located on the side opposite the threaded port above the welding seam around the center of the
accumulator.
※
Wear safety goggles when doing this job.
(6) (6) Performance testing and checking of the accumulator Performance testing and checking of the accumulator
The accumulator is gradually pressurized via the test pump; until the initial gas pressure is
reached, the hydraulic pressure in the accumulator will rise abruptly. This is apparent from gauge
M M . If the initial gas pressure is more than 30% below the prescribed value, the accumulator needs
to be replaced. If the measuring process needs to be repeated, wait for intervals of 3 minutes
between the individual tests. Any accumulator whose initial gas pressure is insufficient must be
scrapped following the instructions under Disposal of the accumulator
The amount of initial gas pressure can also be checked from the vehicle. Start the vehicle's
engine. The pump will now supply oil to the accumulators. Until the initial gas pressure is
reached, the hydraulic pressure in the accumulator will rise abruptly. This is apparent from the
gauge in the cab. If the initial gas pressure is more than 30% below the prescribed value, that
initial pressure lies outside the permissible range for at least one
vehicle. This accumulator can be traced only by using the method described above, i.e. all
accumulators have to be individually tested. The accumulator whose initial gas pressure is
insufficient must be replaced and scrapped following the instruction under Disposal of the
accumulator. accumulator
Accumulator
Ball valve for
shutting off pump flow
(7) (7) Repair work Repair work
When working on the braking system, always make sure that there is absolutely no
pressure in the system. Even when the engine in switched off there will be some residual
pressure in the system.
※
When doing repair work, make sure your environment is very clean.
Immediately close all open ports on the components and on pipes using plugs.
For safety reasons the accumulators need to be replaced as a whole if damaged.
Disposal of the accumulator.
at least one of the accumulators fitted in the
Pressure gauge(M)
Ball valve for
reducing pressure
4-19
Disposal of the
Safety valve
75794BS10