Make sure that a 1.0 mm (1/32 in) diameter drill bit will go through the nozzle hole (A) (1.2 mm (0.047 in) diameter).
Insert the other end of a 3.0 mm (7/64 in) drill into the oil intake (3.2 mm (0.126 in) diameter). Make sure the check ball (B) moves smoothly and has a stroke of about 2.0 mm (0.079 in).
Check the oil jet operation with an air nozzle. It should take at least 175 kPa (1.78 kgf/cm2, 25.4 psi) to unseat the check ball.
NOTE: Replace the oil jet assembly, if the nozzle is damaged or bent.