Operating - Boom opening / closing Unfolding 1. Raise the boom to the top of the height mast ensuring that the centre section hits both the rubber stops. 2. Open the boom out to 12 metres "First fold". 3. Open boom out to full width "second fold" (if required). 4. Lower boom to working height. Folding 1. Make sure you are parked on level ground and are well clear of obstacles and overhead power cables. 2. Using the hydraulic tilt ram ensure that the boom is level. 3. Raise the boom to the top of the height mast ensuring that the centre section hits both rubber stops (Fig. 19). 4. Fold outer sections in to 12 metres. 5. Fold inner sections in until boom touches the vertical plates on the front boom rests. 6. Lower boom right down into boom rests ensuring all the pressure is off the hydraulics and it is seated into the rear rests. Hydraulic break-back On some variants the second fold rams may have a hydraulic break-back incorporated as a safety precaution. This is used when the boom tips (and also the normal break-back) have been removed from the 24m boom for spraying at 20m. If the end of the boom hits an obstacle oil will be forced out of the ram and back to the hydraulic tank through a safety relief valve. The hydraulic pressure will be lost out of the second fold rams and it will be necessary to re-pressurise the by activating the outer section spool lever or switch before continuing. Whilst the boom is being used at 24m the break-back system should be switched off or un-coupled     Front boom rest Rear boom rest < 25 >