Fill the pulse unit with oil on a regular basis
It is necessary to fill the pulse unit with oil on a regular basis to compensate for micro leakage of oil between the outgoing shaft and the sealing o-ring. This is a normal occurence in hydraulic systems. Between overhauls regularly fill up the pulse unit with a small amount of oil without disassembling the pulse unit. The need for adding oil to the pulse unit will vary depending mainly on the number of tightening, torque level and number of pulses (tightening time). The need to add oil regularly to the pulse unit will normally decrease because the o-ring will seal better after a period of use. When the o-ring is changed the need to add oil regularly to the pulse unit may increase again.
Do not change the o-rings in the pulse unit except at the regular overhaul once per year or after a maximum of 250.000 tightening.
Negative effects of to little oil in the pulse unit:
Longer tightening time
No shut off
Decreasing torque
Increased scatter
Faster wear of the parts in the pulse unit
How to detect a low oil level in the pulse unit:
Increased pulse frequency
Low torque, no torque or abnormal torque changes
Very high pulsing speed, especially when the tool has not been used for a while.
Regular measurement of the pulse frequency is the best method to detect a low oil level in the pulse unit. If the pulse frequency has increased, preventive oil filling can be done before a low oil level in the pulse unit affects the function of the tool. The pulse frequency can be measured with a static torque transducer (SRTT) or an inline transducer (IRTT) connected to an ACTA 4000 instrument.
