Pressure washer, vibration, spitting, loss of pressure

Joined
Feb 20, 2007
Messages
7,701
Location
Southeast
I’ve got a frankenbrew pressure washer.. an AR pump mated to a predator engine. It gets used 4-5 times per year, 3-5 hours each time, and always stored with pump saver run through it with the rope pulled a few times.

yesterday I ran it about 3 hours, and it never made full pressure, the engine never hit its normal “loaded up” sound with it, and if I pulled the head off of it, so that the water freely shot from the high pressure hose, it kind of “spit” 1-2 times per second. Under load, normally the hose never shakes and the handle resonates with a singing tone, but yesterday the whole thing sort of shook in time with engine rpm.

the last oddity - a small 3” pool of thick white goo, smelled like silicone paste grease, was left on the ground under the washer after use (maybe it was old pump saver fluid?) and it could be just splash, but a couple of drops of water seemed to be atop the pump in a crevice in the copper. This is an oil filled pump.

other clue - on handle release, it would take up to a full second to build line pressure to where the unloader valve would kick over.

thoughts? Is it cooked? The pump is 10 years old. We did have a significantly cold snap this year where outdoor temps were 4f, probably below 30 in the garage, but again, it would have had a good application of pump saver in it.

edit- note, it still functioned… but probably at 70% it’s normal…

thoughts?

-m
 
That goo you describe is most likely water getting past the pump seals into the oil. At the very least the seals may need to be replaced. If you tear it down have a good look at the ceramic pistons, they can crack. Look carefully for hairline cracks as well. I have a set of pistons and seals sitting on my work bench in the garage. I put new seals in my 35+ year old power washer three years ago, this past season water started mixing with the oil. I have a piston with a hairline crack in it. The rebuild is on my to do list.
 
That goo you describe is most likely water getting past the pump seals into the oil. At the very least the seals may need to be replaced. If you tear it down have a good look at the ceramic pistons, they can crack. Look carefully for hairline cracks as well. I have a set of pistons and seals sitting on my work bench in the garage. I put new seals in my 35+ year old power washer three years ago, this past season water started mixing with the oil. I have a piston with a hairline crack in it. The rebuild is on my to do list.
^^^^^ this, sounds like you need a pump rebuild.

FWIW I use RV antifreeze in my power washer. I have an RV so I use some extra to winterize my pump. I put a funnel and hose on the inlet and fill it with anti freeze. I actually start the motor and let it suck in all the fluid. I rinse and repeat this process until the fluid coming out the pressure port is pink (antifreeze). It is usually 2 or 3 cycles.

Just my $0.02
 
^^^^^ this, sounds like you need a pump rebuild.

FWIW I use RV antifreeze in my power washer. I have an RV so I use some extra to winterize my pump. I put a funnel and hose on the inlet and fill it with anti freeze. I actually start the motor and let it suck in all the fluid. I rinse and repeat this process until the fluid coming out the pressure port is pink (antifreeze). It is usually 2 or 3 cycles.

Just my $0.02
I've winterized my power washer for the 35+ years I owned it with the funnel and hose, and RV anti-freeze as you described. For the original pump and commercial use, it did well. I have the parts on hand and will be rebuilding it shortly.
 
Ok - thank you for the tips. So this isn’t the end of the world… replacement parts can be had, it sounds like. thank you.
 
Ok - thank you for the tips. So this isn’t the end of the world… replacement parts can be had, it sounds like. thank you.
No problem! Parts are around, depending on the pump brand, etc. I got my parts on Ebay, it took a bit of searching for the pistons, but I was able to get them.
 
update. I pulled the “head” off and found where it’s leaking a little oil, and somehow combining with water, and the white goo is weeping out of drain holes. Visual inspection sees nothing wrong, no cracks, cuts or scrapes on the pistons or sealing surfaces.

my AR pump is an odd size… it’s not listed on domestic parts houses but shows commonly on European sites. It was installed by a local fix-it-shops a decade ago. Who knows how they got it? I’ve emailed a supplier to see if I can get the seal/valve kit. I might fix it, however I’ll admit, the idea of upgrading to a 4gpm unit is very, very attractive. im running a 3100psi, 3gpm pump now. honda motor with a cat pump is very attractive.
 
Back
Top