I have a Model K2301 Karcher pressure washer. It has.approximately 50-60 hours of use on it. Unit will not go to high pressure. I have tried using vinegar solution run through the cleaner hose but this has not fixed the problem. I have verified that it is getting an adequate supply of water. There is no water leaking from the pump, so I do not think that the seals are bad. There is also no oil dripping. Is the escape/pressure valve the issue? Tony Gilman metalman@hbci.com 507-452-4457