1.Loosen the 4 screws between aluminum head and gear box by 12mm HEX head wrench.(See Fig1)

2.Disassemble the aluminum head, cylinder and piston.(See Fig2)

3.Clean the inside of aluminum head, must be free of metal chip and granular dust (See Fig3)

4.Clean the piston and cylinder.(See Fig4)

a)Clean the cylinder both inside and outside, especially clean the inside of cylinder, must be free of metal chip and granular dust. If the conditional, recommend washing by gasoline.

b)Clean the surface of piston. 。If the conditional, recommend disassembling the O-ring and washing the piston by gasoline.

c)At the same time, check the wearing condition of O-ring. If the Outside Diameter (O.D.) of O-ring is less than the piston O.D., please replace the O-ring to get proper performance.(Please contact with our authorized dealer to purchase, the part No 56).

5.Fill the grease into the aluminum head, please make sure cleaned inside before filling.

a)Recommend the grease from manufacturer site, there is a tube of 60g grease included the case. (Please contact with our authorized dealer to purchase, the part No 108).

Notice：There are 4 grooves in the aluminum head, Please fill the grease in all these 4 grooves by 15g in each, and total 60g grease. (See Fig 5 and Fig 6)

6.Fill the 15 g oil in the cylinder; please make sure it is clean before filling. (See Fig 7)

7.Assemble back(See Fig 8)

a)Assemble the piston into cylinder, please make sure if the O-ring has been assembled.

b)Assemble the cylinder into aluminum head.

c)Tighten the 4 inner HEX head screws; be careful of no missing spring washer. If tighten the screws by electrical or pneumatic driver, please check the torque of screw by 12mm wrench to make sure tightening properly.

d)If the conditional, can put glue on the screw and then screw in(repeat the step above C)

*Suggestion: All above operations to be carried out by our authorized service agent.

XP-G90A MANUAL