Generac Pressure Washer Pump Repair

[ponytug]

Funnily enough, mine (same design, but not Generac) would not start today. After checking for spark, and enough oil, I drained and pulled the fuel tank to get to the carburetor, opened up the carburetor drain screw, and shot some acetone (brake cleaner) up into the carburetor, and let it drain, a couple of times. The last squirt I left in the carburetor and tried starting the engine. It ran on acetone, so I drained the acetone, reinstalled the fuel tank, added back the gas that I had drained out, and changed the oil because I might as well since I am into the machine anyway. 20oz per the manual 10W30.

FWIW: The carburetor drain screw is on the other side from the fuel pump, and you don't have to pull the fuel tank to get to it.

Runs great now! My note to self is don't leave gasoline in the carburetor too long.

All the best,

Peter

 

[polarred21]

So last weekend removed the fuel pump and tried to bypass it, would not start, duh.....blew it out good, another drain and flush, and engine starts and runs flawlessly. Let it run several minutes with no water in the pump, didn't care about the pump at this point.

So spending just a little time on the pump, full of oil, looks okay. Had to get cutoff wheel to remove plastic hand sleeve at pump hose connector, seems the aluminum and brass have married to each other over time. A little heat and got it removed. Pulled the unloader valve and top valve body to find it full of corrosion, feels like salt inside. Cleaned and lubed with marine grease and had to stop, has sat for a week. Will test the pump once more and go from there.

 

[ponytug]

Great news on the fuel pump! Congratulations.

That crud looks like either hard water or aluminum corrosion salts from water bypassing the unloader valve. If the unloader cylinder walls aren't too scored, I would clean the walls out, clean the unloader assembly, replace the o-rings, and you should be back in business. I would measure the thread length, or spring compression length or both before disassembly, otherwise you will need to be adjusting it with a high pressure gauge.

All the best,

Peter

 

[polarred21]

Well that's a wrap. Maybe 6 hour total labor and zero expense required. Works like a new one. Did buy the $30 pressure gauge to set to pressure. Rated at 2400 psi, can only get 2000 psi with trigger pulled, set relief pressure at 2400 psi.

Other than usual gas issues with the engine and carb, cleaning and flushing was all that needed. Did replace the suspect hose from the crankcase to the diaphragm fuel pump.

The pump itself was really cruddy inside from the breakdown of the aluminum and other metals on well water. Had to disassemble twice for cleaning and liberal with marine grease. Changed oil in the pump, there is no drain plug. Will definitely be lubing my pumps now periodically.

Washing one relic with another....

 

[CADplans]

I just went through the pressure washer parts hunt,,
I could not figure out what I needed to order, a replacement pump was under $200,,
so, I figured ,, what the heck, get a pump.

4GPM at 3600 PSI,, I really enjoy the pressure washer.
If this pump does not last, I will get the CAT pump,, but, that pump is $800,,,

I probably lost the old pump to corrosion/freezing,, who knows,, can't cry about it, I got over ten years out of the original pump.

The 13HP Honda runs like new,,
I almost got it out today,, the weather was so nice,,

I am thinking about building a storage box for it, and adding a heater to the box to stop freezing.

What about running old hydraulic oil through the pump??
That would stop freezing, and lube the pump.
I have LOTS of clean hydraulic oil every time I change the hydraulic oil in a tractor,,
Hmmmmmmmmmm,,,