How to Rebuild a Graco Paint Gun

Graco specialize in the production, distribution and application of fluid-handling systems. The company, which has been trading since 1926, has built an outstanding reputation based on premium-quality products, advanced technical innovation and excellent customer service. Paint guns contribute to a significant proportion of the Graco market share and many refinishing professionals use their products for the application of base colors and clear coats. To extend lifespan and to ensure they work correctly, Graco guns should be stripped regularly to enable thorough cleaning of spray chambers and component parts. Reassembly is a relatively straightforward process.

Instructions

1

Remove the Graco spray gun and components from the gun cleaning machine and lay them on a flat working surface and leave for 15 minutes to allow thinners to evaporate.

2

Take the air control assembly and reinstall it at the rear lower section on the gun. The valve should be fully turned, in a counter-clockwise position, to a torque measurement of 85 to 90 inch-pounds. This will set the valve to the outermost position, leaving it ready for calibration when it is next used.

3

Replace the air inlet assembly, ensuring the valve is turned to the outermost position. Tighten the air inlet assembly to a torque measurement of 205 to 215 inch-pounds, working in a counterclockwise direction.

4

Lubricate the U-cup spreader and packing with a small amount of silicon-free paint gun gel. Insert the spreader into position, making sure that the tapered end faces the rear section of the gun. Place the packing over the top so the spreader is held into position and tighten the packing screw to a torque measurement of 3 inch-pounds.

5

Replace the wave washer, ensuring that the cupped side is located directly towards the body of the gun. Lubricate the wave washer with silicon-free paint gun gel. The trigger, the trigger nut and the trigger pin can now be lubricated and assembled before being refitted to the gun to hold the wave washer in position. A torque of 15 to 20 inch-pounds is recommended.

6

Hold the air valve assembly, spring and nut in position loosely between the fingers and screw into position behind the trigger mechanism. Tighten to 175 to 185 inch-pounds.

7

Push the fluid needle into position through the rear of the gun and place the spring over the wider section of the exposed needle. Lubricate the retaining nut with silicon-free paint gun gel and screw into position. This is an adjustable section of the gun that requires no torque calibration.

8

Pull back the trigger of the gun and fit the nozzle into the air assembly chamber. Tighten to 155 to 165 inch-pounds. Place the air cap assembly over the nozzle and tighten into place with the retaining ring. The retaining ring only needs to be hand tight to stop the air cap assembly twisting or moving.