13.9.3 Maintenance

A routine preventive maintenance programme should be drawn up. This should meet the requirements set out in the manufacturer’s maintenance instructions in addition to any requirements of the particular site due to the conditions of service. In any event attention should be given to the following points:

  1. In particular, attention should be given to the lubrication of the rack or screw mechanisms of mechanical jacks.

  2. In the case of ratchet jacks, regular cleaning and occasional adjustment of the lowering spring mechanism may be necessary. Care is necessary as the excessive use of grease can cause the holding pawl to stick or become retarded in its operation. If the holding pawl does not fall into place correctly, the rack will become free and will fall thus dropping the load. A similar condition can arise from the incorrect fitting of the mechanism or the use of incorrect parts. It is imperative that only the original manufacturer’s approved spare parts are fitted and that this is done strictly in accordance with their instructions.

  3. Oil levels of hydraulic jacks may require occasional topping up or the oil may require periodic draining and replacement. It is essential to the correct operation that the oil level is maintained and that the oil is clean and free of any dirt or debris. Only oil recommended by the manufacturer should be used.

  4. In all cases, jacks should be cleaned regularly to remove any dirt or debris, paying particular attention to the racks and screws of mechanical jacks and to the area around the top ram seals of hydraulic jacks, which may interfere with the correct operation or otherwise cause damage to the jack mechanism.