OPERATION
8.After the rock bit has carved out a depression in the material being drilled, open the hydraulic valve le- ver fully. Readjust the motor control knob to obtain a good drilling speed. Adjust the air valve to ensure the cuttings are being extracted from the drill hole.
9.When the bottom of the tool comes within 6 inches of the drill hole, it is time to either add another sec- tion of drill steel or replace the existing drill steel with a longer section. Close the hydraulic valve lever but leave the air valve “ON” and then lift the tool with drill steel and rock bit out of the hole. Leaving the air valve “ON” helps prevent cuttings from falling around the bit while the bit is lifted from the hole.
10.When the tool, drill steel and bit have been removed from the drill hole, turn the valve lever “OFF” and turn the hydraulic supply circuit control valve “OFF” before changing the drill steel or rock bit.
COLD WEATHER OPERATION
If the breaker is to be used during cold weather, preheat the hydraulic fluid at low engine speed. When using the normally recommended fluid, fluid temperature should be at or above 50 °F/10 °C (400 ssu/82 centistokes) be- fore use.
Damage to the hydraulic system or breaker can result from use with fluid that is too viscous or thick.
SK58 User Manual ◄ 11