Airless Spray gun spitting or not shutting off completley possible causes.
Paint spitting from your airless spray gun when you pull the trigger or release the airless spray gun trigger can be annoying and ruin your airless paint spray job.
Spitting airless paint spray guns can be caused by several common issues.
Diagnosing problems with valves in hydraulic diaphragm airless paint sprayers.
Hydraulic diaphragm airless paint spray machines are usually fairly basic simple machines with not much to go wrong. Unlike piston airless paint sprayers the valve action in diaphragm airless sprayers is much more passive and susceptible to problems that may not ordinarily affect piston pump.
A piston airless paint spray may effectively continue to operate using only one of the two valves commonly found in piston airless paint sprayers and enable the operator to complete a job.
Diagnosing problems with airless piston pump pressure valves.
Here is a way to test your piston airless spray pump to ensure the inlet valve and outlet valves, including the relief valve are functioning correctly.
This test is much easier to do and see the results with a large longer stroking airless piston pump compared to a small short stroke fast cycling piston airless sprayer.
A small airless spray tip that slows the output of the airless piston pump will make this test easier to read.