HP AUTOMATIC XT SPAY GUNS 311051D - Manual (Page 20)

Troubleshooting
20 311051D
Troubleshooting
General Troubleshooting
Check all possible remedies in the troubleshooting
charts before disassembling the gun.
Some improper patterns are caused by the
improper balance between air and fluid. Refer to
Spray Pattern Troubleshooting, page 22.
Problem Cause Solution
Fluid leakage through venting holes. Worn packing (17) or needle (5). Replace packing or needle.
Air leakage through venting hole. Worn o-ring (9) or gasket (15). Check and replace parts as needed.
Air leakage from back of gun. Worn o-rings (8, 9). Replace o-rings.
Air does not trigger. Piston stem is disconnected from
main body of piston assembly (3).
Cylinder air pressure is too low.
Replace piston assembly.
Increase cylinder air pressure to 50
psi.
Air does not shut off. Piston assembly not seating properly.
Broken return spring (7).
Swollen o-ring (8).
Worn piston stem o-rings (10, 11).
Bottom gasket (12) failed.
Clean/service piston assembly.
Replace worn or swollen o-rings.
Replace return spring.
Replace o-rings.
Replace o-rings.
Replace gasket.
Fluid leakage from front of gun. Fluid needle tip (5a) is dirty, worn, or
damaged.
Dirty or worn nozzle (23).
Clean or replace fluid needle tip or
entire needle (5).
Clean or replace nozzle.
Fluid is present at air cap holes. Nozzle (23) is insufficiently tightened
or sealing o-ring (36) is damaged. Tighten or replace o-ring.