I got a freebie pressure washer from a coworker. It is a small homeowner unit but it runs and builds pressure just fine after I cleaned it out. What does not work is the detergent inlet. I took the inlet connector off the pump, soaked it in vinegar to boil off the calcium deposits, then ran it through an ultrasonic washer for 30 minutes and blew it out with air pressure. I also sprayed some oil in there. It looks nice and clean now. The check valve will not un-stick no matter how much air pressure I put on it. Should I try soaking some more? This is a cheap Generac 2100 PSI unit that was free. Its no big deal if the detergent doesn't work, I can still use it to blast and rinse. I plan to put new pump oil in it, change the engine oil, and maybe put a shot of PumpSaver in the water inlet later this fall. Other than that I will not spend any money on it.