7.3.7 Braking valves operation check
These valves check the minimum operating pressure during drive (in both running directions) and affect the dynamic braking and
the drive speed. Normally, these valves do not require any adjustment, since they are calibrated at the factory before the machine
is delivered.
The braking valves stop the machine when the drive controls are released. Once the machine has stopped, the parking brakes
automatically come on, thus keeping the machine in position.
Check operation at least once a year.
To check the operation of the braking system:
▪ With platform completely lowered place the machine on a flat ground, free of obstacles, operate the drive control and when the
max. speed is reached, release the control immediately.
▪ The correct operation of the braking system allows the machine to stop within a distance lower than 70 cm.
▪ In any case the braking system can stop and keep the machine on slopes as indicated in "Technical features" (the braking
distance on descents is longer; drive downwards at the min. drive speed).
Calibration of both braking valves is required:
▪ In case of replacement of the hydraulic unit A.
▪ If one or both braking valves are to be replaced.
To calibrate the braking valves:
▪ Locate braking valves C (one for each running direction).
▪ Introduce a pressure gauge with full scale of at least 250 bar in the special quick coupling of hydraulic control unit (1/4” BSP) D.
▪ Using the platform control panel select the minimum drive speed.
▪ Unscrew the lock-nuts of the adjusting dowels.
▪ Using the platform control panel drive the machine (in the direction controlled by the valve) on a flat ground in straightforward
direction and adjust the braking valve (relevant to that running direction) by means of adjusting dowel so as to achieve the
required pressure value (call the nearest Service Centre to ask for the exact value).
▪ Once the required pressure value has been achieved, check that the valve controlling the braking in the opposite direction has
maintained its adjustment.
▪ Once adjustments are complete (pressure values in the two directions must not vary by more than ±5 bar), lock the adjusting
dowel by means of the lock-nut.
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