Comet water oil

30 weight NON DETERGENT. Autozone and other autoparts stores usually have it. It is often hard to find, so you might have to ask them where they hid it.

Things to check:
1) is water coming out of the bottom of the pump or is the oil in the crankcase high level and milky yellow. If so your seals are bad.

2) Your check valves might not be seating properly. A couple of fouled check vavles will cause either no pressure or pulsing pressure. A good inlet water strainer keeps foreign matter out of valves. But valves do wear out and get build up that keeps them from working right.

3) Your unloader valve might be worn or fouled. Bad unloader would usually show as low pressure ( but more than hose pressure) or low volume out the trigger nozzle.

Valves are your most likely problem.

out the drain plug ? Sight glass window ? Under the pump where the crankcase meets the pump head?
tighten plug, replace oring on sight glass or replace low pressure seals if near the pump

service manual
https://www.pwmall.com/PDF/CometServiceManual.pdf

what you have is a bad seal or a crack within the pump crack more common if any water was left in it during the cold winter

You have a seal on the pump between the pump and the water pump thats leaking you have oil and water mixing . I owen three mechines and i don't understand what you mean when you say the oil filler stem. I also rebuild power washers and pumps. If you can clarify where the water and oil mixture is comeing out then i can tell you excatly what the leak is thanks

You have a seal failure, you need to reseal the pump and change the oil in the pump.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/matt_8dbc24bf722649ac

More than likely you have water leaking into your oil, making the oil float on the top and out of the vent. Eventually you'll only have water, and no oil. Drain oil and replace. You will probably have to replace the seals between pump and crankcase. Only remove front of pump,(brass part) if you catch it in time the bearings in the rear portion won't go out. Do it now before the water wears the pump out. You can get parts for most pumps at www.pressure-washer-parts.com. Or go to www.cometpumps.com Hope this helps.

Hi this could be the oil and pump seals worn. Also make sure that you don,t have the transit plug in or the pump cannot breath. It should have a air vented dipstick.

aftermarket oil will be fine just use same grade of oil,all manufacturers want that extra kick,