This part of ISO 789 specifies test procedures for determining the following hydraulic performance characteristics of agricultural tractors:
a) the maximum vertical force which can be exerted by the hydraulic lift at the lower hitch points throughout their full range of movement;
b) the maximum vertical force which can be exerted by the hydraulic lift, at a point 610 mm to the rear of the hitch points on a frame attached to the three-point linkage, throughout its full range of movement;
c) the maximum hydraulic power available at an external hydraulic tapping;
d) optionally, the ability of the lifting system to maintain the load in the lifted position without hydraulic power.
NOTE — To ensure that the lifting capacity and the hydraulic power are adequate for effective practical use and also to allow for variation in the performance of nominally identical tractors, the measured maxi-mum performance is reported as that which would be obtained with the hydraulic fluid pressure maintained at 90 % of the pressure sus-tained by the relief valve (see 5.1.3.4).
DS/ISO 789/2:1983 history
1983DS/ISO 789/2:1983 Agricultural tractors. Test procedures. Part 2: Hydraulic power and lifting capacity