Continuation of Pressure Washer Problems

Craftsman Gas Model # 580.752102. Some time back I tried my PW first time of year. It started fine but would instantly quit. Short story--unloader was stuck. Would run and have lots of pressure with trigger pulled, engine stopped immediately when trigger released. After much procrastination I finally ordered a new manifold and unloader (I said unloader was stuck--would not come out of manifold). Put all together today, purged water from hose, engine starts and runs fine but have no pressure. When pulling trigger I get lots of water, but at house pressure, not PW pressure. Am I suppose to adjust unloader or just snug up locking nut (it was loose)? Any thoughts? I did spray some "Pump Defender" in it and am leaving it soak for a while. I never used the defender before--which probably is the heart of my problems.

 

Hard to guess, but something is out of place, missing, or stuck. Check the little plastic check valves for trash in them and make sure they are working freely. If just one isn't sealing properly it can cause your problem.

 

Thanks Cheese. I took the manifold back off and checked the three valves (I assumed those were what you were referring to) but they seemed OK. I pulled off the bottom of the pump and checked for anything that looked "wrong" there but everything seemed OK. I also had my wife pull the rope on the engine to make sure the pistons (I assume that those were the pump pistons sticking down from the pump) were moving freely and all three seemed to move OK. After putting it all back together I still had the same thing. Water moves through the machine fine, just no increased pressure over house pressure. A month ago it produced all kinds of pressure, just couldn't "unload" it, now with a new manifold and unloader I have no pressure.

 

My Karcher had a similar host of problems. I wound up buying a kit from them. That fixed it.
(the Tecumseh Carb is still a big problem though)

 

I've taken the bottom off the pump. Taken all six valves apart and blown them out with compressed air. Blew out every port, hole or whatever. Made sure all O-rings were where they belonged. Put it all back together but still no pressure. When squeezing the trigger on the wand I get plenty of water--just at house pressure. The motor does not "lug down" as it used to when trigger was pulled. Could there be a problem with the new unloader? Could it be "unloading" all the time? How could I check this?

 

It could be the unloader. Make sure everything is in the correct order and moves freely. Lube it if needed with silicone grease. Does the unloader have an adjustable spring tensioner?

 

Yes, Cheese it has a tensioner. For the record it is Briggs & Stratton part number 190594GS. On another website it was suggested that I need to adjust it. However, no matter how much I tighten the spring it does not affect the pressure from the machine. I'm not sure of the correct procedure, I can not find any instructions about adjusting the unloader, but I loosened the small lock nut, held the stem with a screw driver while using a wrench to tighten down the nut that compressed the spring. I did it in stages, turn a little, test, turn a little, test. Nothing. Water still comes out at house pressure, motor does not change rpm's (before when squeezing the trigger the mower would "lug down" as pressure built). I'm going to follow your advise today, pull the unloader back out, try a little grease and put it back. The seal should be good as the unloader and the manifold are both brand new. I have a check valve repair kit on the way (which I think is what hoary suggested), if that doesn't fix it, then it becomes junk. I'll have more than $130 invested and that's enough. Thanks for you help. I'll let everyone know the results.

 

Well the end as come. I installed the check valve kit but as expected it did not help. I now have $131 invested with no desire to waste any more money so the unit is setting out at the curb waiting for the junk guy that comes around every so often. Too bad, it is a very good engine on the unit that starts on the first pull almost every time. The worst part (besides the waste of money) is that I've always had a knack to be able to get something running again or fix whatever is wrong with something. Whether it be mechanical or what. I'm retired, must be time to also retire from DIY.

 

Since you are retired why trash it, make it a temporary hobby, I fixed mine for about $15, It's a "the water comes in here and goes through there and comes out here", just follow the flow, mine was melted valves. Have a good one. Geo

 

Yep, these things are not well made in the first place. If you follow the water through the valves and passages like geo mentioned, you can usually figure it out. Retire from DIY?? Retirement is the perfect time to take up DIY!

 

I think I'll pull that pump off and tear it completely apart and see if anything strikes me. I'm pretty sure I know what happened. The pump is obviously not building any pressure, the motor runs, the water goes through just no pressure. I've pulled that bottom part off and all valves, etc. look good (or course they are new now) therefore it has to be up in the pump itself. The motor must be "in contact" with the pump, when I pull the rope with the bottom off the three pistons work up and down. There must be something, like a gasket, blown in the upper chamber. When the trouble first started, the motor would start and run--as long as I held the trigger on the wand. There was plenty of pressure as should be. But, when I released the trigger the motor died--and died "hard." Since the unloader wasn't working there was too much pressure and it killed the motor. I believe it also damaged something in the upper chamber of that pump. There are no kits for the upper part and I'm not buying a new $200 pump so this might be just for fun.