DeVilbiss Viper Operation Manual page 8

FIG 1
PACKING
Unscrew the 4 screws to disassemble the gun head. Remove the packing bellows seal. Clean or
replace if the packing is damaged.
FAN & ATOM AIR VALVE (13)
Before assembling, check the air valve is in fully open position by
unscrewing it counter-clockwise.
Piston (15), o ring (16) & (14)
Unscrew the rear housing (19) at the back of the gun body counter
clockwise, pull out the needle (18).
Use bent nose pliers so to pull out the piston which has a 12mm
internal groove for this purpose.
It's recommended to replace the o ring
you disassemble the Piston.
When replacing the piston, slightly lubricate all the O rings before fitting
into the gun body.
PREVENTIVE MAINTENANCE
1. Turn off air and coating supply and relieve pressure in the supply lines, or disconnect from
airline and fluid line.
2. Remove air cap and clean. If any of the holes in the cap are blocked with coating material use
a toothpick to clean. Never use metal wire which could damage the cap and produce
distorted spray patterns
3. Ensure the fluid tip of the nozzle is clean and free from damage especially the outside at the
front diameter. Any build up of dried paint can distort the spray pattern.
FIG 2
(14) into the gun body as soon
8