Hi, I bought a used 509 Wagner Professional Airless paint sprayer at a auction. The previous owner used in a cabinet shop. Besides the motor, I am taking the unit apart to service, basically get rid of all the dried paint, remove rust, clean the springs, etc. The previous owner did not take care of. My questions are: How do I clean? What is best solvent/cleaner to use? The paint that is dried in there is hard and chalky. I have some parts sitting in mineral spirits, this is not dissolving the paint. So is it latex? If so, how do you remove latex paint? What is best tool to use to clean the parts? The parts that are in the gun, the housing on the front of the pump apart. (where the gun connects to and hose that goes in paint). I have used a battery terminal cleaner to get in the male parts threaded part and that works great. Any suggestions? Does anybody know how to get a onwer manual, wagner's website wants a model #, and the only model number is on pump housing for the pump not actual sprayer.