Anyone ever rebuild a pressure washer pump?

[ProjectBazza]

Mine (gas powered) has been acting up lately, and I think one of more of the valves are either blocked open (debris, etc), or damaged due to overheating, as I didn't know you're not supposed to let it run for over 30 seconds without pulling the trigger (Ooops!).

I'll know more this evening (hopefully), but for now I'm just curious if anyone has ever dug into this before, as a Search here came up mostly empty.

 

[toolmanmike]

Mine (gas powered) has been acting up lately, and I think one of more of the valves are either blocked open (debris, etc), or damaged due to overheating, as I didn't know you're not supposed to let it run for over 30 seconds without pulling the trigger (Ooops!).

I'll know more this evening (hopefully), but for now I'm just curious if anyone has ever dug into this before, as a Search here came up mostly empty.

I think they are pretty easy to rebuild. Finding parts is the hard part. Most of the pressure washers sold now days are cheaply built and considered a throwaway.

 

[AJ/FormS]

I've never had one but I've worked on a few.
I didn't know about any 30 second unloader rule.
In any case, they're really simple little devices and I've rebuilt quite a few. Mostly what I see is is crudded up unloaders running on chlorinated water, which creates a greenish powder, when left to dry out.
I can only imagine what is does inside your body..............

 

[ProjectBazza]

I think they are pretty easy to rebuild. Finding parts is the hard part. Most of the pressure washers sold now days are cheaply built and considered a throwaway.

Thanks, Mike.

That's what I'm doing now- trying to find parts (vendors) for it. It's a Northern Tools unit with an upright (horizontal shaft) Honda engine with what I think is a Comet pump, but it would be a helluva lot easier if I knew for certain, as I'm going by pictures (and visual memory) at this point. And my wife isn't home to get me any numbers off of it....

If I have the time I'll dig into tonight, and if I can find parts for it: Great!

And if not, well, it was going bad anyway....

 

[ProjectBazza]

I've never had one but I've worked on a few.
I didn't know about any 30 second unloader rule.
In any case, they're really simple little devices and I've rebuilt quite a few. Mostly what I see is is crudded up unloaders running on chlorinated water, which creates a greenish powder, when left to dry out.
I can only imagine what is does inside your body..............

Thanks! I didn't know about the 30 second thing either, but I'm finding mention of this all over the interwebs. And since I'm one of those guys that actually reads the Owners Manual, I don't remember ever seeing this, so I downloaded a few this morning, and.....Nothing!

I'll try to open up the valves tonight and take a few pics.

 

[1WildRT]

What is it doing? pull the trigger and nothing? Then sometimes it does work? Hold the trigger & it sometimes after not working comes alive. If so that's the unloader that AJ mentioned.... Leave most of the pump alone, pull the unloader & polish it with a fine scotchbrite pad...

"Not supposed to let it run more than 30 seconds without pulling the trigger..." BS... The unloader allows the pump to bypass, not a big deal...

I try to blow all the water out of the pump when storing my unit & I spray WD-40 into the inlet & with the ignition off I pull the starter rope a few times...

My current unit is 12 years old.. My last one was a cheap unit & lasted 25 years...

 

[ProjectBazza]

What is it doing? pull the trigger and nothing? Then sometimes it does work? Hold the trigger & it sometimes after not working comes alive. If so that's the unloader that AJ mentioned.... Leave most of the pump alone, pull the unloader & polish it with a fine scotchbrite pad...

"Not supposed to let it run more than 30 seconds without pulling the trigger..." BS... The unloader allows the pump to bypass, not a big deal...

I try to blow all the water out of the pump when storing my unit & I spray WD-40 into the inlet & with the ignition off I pull the starter rope a few times...

My current unit is 12 years old.. My last one was a cheap unit & lasted 25 years...

It's to the point where it builds pressure (you can see it and hear it), but when you pull the trigger: A little high pressure "spurt" comes out, but after that it's just like running the hose without the pump, if that makes sense. A good analogy would be that the pump just can't seem to catch-up. The unloader/pressure regulator seems to work ok (to me), since if I back it off I get a little "spurt", and if I crank it down I get a bigger "spurt", and based on what I've seen online today everything points to one or more broken valves.

As for the 30 second thing, I have my doubts as well, but it makes sense (at least a little), as an internally bypassed regulator would just dump the "pilot" water into the other side, causing some "draw" on the seat.

Either way, hopefully I'll be able to dig into it this evening. Just looking for someone who's "been there, done that" to see if there are any tips or tricks to be aware of.

 

[1WildRT]

It's to the point where it builds pressure (you can see it and hear it), but when you pull the trigger: A little high pressure "spurt" comes out, but after that it's just like running the hose without the pump, if that makes sense. A good analogy would be that the pump just can't seem to catch-up. The unloader/pressure regulator seems to work ok (to me), since if I back it off I get a little "spurt", and if I crank it down I get a bigger "spurt", and based on what I've seen online today everything points to one or more broken valves.

As for the 30 second thing, I have my doubts as well, but it makes sense (at least a little), as an internally bypassed regulator would just dump the "pilot" water into the other side, causing some "draw" on the seat.

Either way, hopefully I'll be able to dig into it this evening. Just looking for someone who's "been there, done that" to see if there are any tips or tricks to be aware of.

Your spurt is exactly how the unloader acts.... Try that first, it's easy, and I'll bet it's where your issue is..

 

[A56]

 

[Inertia]

We have a pressure wash in use at the entry to our car wash.
Dude walks around vehicle shooting wheels, lower body and dirt buildup.
Then he applies cleaner to w/walls - hand scrubs tires/hubcaps,
The machine can be on for very long lengths of times on by-pass, depending on line-up of cars.
Any loss of pressure the 3 valves were checked, and/or exchanged with a buncha other cleaned ones onhand.
That was usual culprit, one valve sticks open/partial open.
That things still going 40+ yrs later, have it here at home .

 

[4spdragtop]

One thing I just watched on Boobtube was mentioning to flush garden hose of the hot water that may be in the hose before hooking up. Apparently the internal seals etc dont like hot water.

 

[George Jets]

Yeah tried to repair, no joy.

Then found an exact new replacement pump on Amazon for $110.00

Worked like a charm.


☆☆☆☆☆

 

[RustyRatRod]

I've never heard of the 30 second thing, either. That said, believe it or not, I have an electric pressure washer now I got from HF and am pretty dang happy with it. It works good. It's the 2300 PSI model but now they have a 3000 PSI version, too. Motor only starts when you pull the trigger.

 

[Mopar Momzee]

Also tried to rebuild but was easily found on amazon I think I paid 60$

 

[ProjectBazza]

Think I just found something…..

Never had an issue with this pressure washer when we lived in the ‘burbs, but now we’re “out in the sticks” a way and have our own well. We installed a whole house filter when we moved-in, but every now and then something in the system gets loose and jambs up the toilet valve, a faucet, etc.

Submitted for your approval, Exhibit A: No water inlet screen.

And Exhibit B: Two check valves stuck open with sand in them.

Pretty hard to see there (I’m no photographer), but zoom in on this one to see the single grain of sand for an example of what was holding one of these open:

Blowing through them can make them stick in the open position at times, and the o-rings are damaged, so for now, just for shiggles, I’m going to throw it together and see what happens. And IF it works, and IF I can find new parts for it, I just may be able to save it

And I’ll open up the regulator/unloader as well when that time comes.

More to follow…..

Edit. On second thought, I have too many other things to do, so I’m NOT going to take the time and reassemble it until I have the new parts in-hand.

Edit ditto. But on the third hand, why order parts for a something that’s dead? Let me see if I can scrounge up a screened inlet washer here….

 

[ProjectBazza]

Update: No joy on putting the old check valves back in, and the regulator was full of **** and came part in my hands.

Guess I’m buying a new pump.

 

[1MeanA]

I have a similar problem....it stalls when I let go of the trigger. I cleaned the bypass unloader valve but it still happens.

 

[ProjectBazza]

I have a similar problem....it stalls when I let go of the trigger. I cleaned the bypass unloader valve but it still happens.

I sincerely hope you have better luck at fixing it than I did. Based on a video I found right before I left work (link below) that shows exactly the same issue and symptom as mine, I was pretty sure I could get it, but then....Poof!

"Men plan & God laughs", I guess.

My new pump should be here on Thursday....allegedly.

 

[missing linc]

Mine was acting up a bit last time we used it too, found that as long as I kept the trigger open it worked fine, gonna have to take it apart and see, last time my buddy got it going in about 10 minutes, but he's been working on this kind of thing for over 40 years.

 

[jas0162]

I have rebuilt many pressure washer pumps, I used to work for a company that sold and serviced them.

The reason for not letting the pump bypass a long time is that it can cause pump damage/failure. Ive never heard of 30 seconds, we used to tell people 2 minutes. What happens is the small amount of water going around and around in the pump and unloader can get very hot over time, and when you pull the trigger the cold water rushing in can crack the ceramic plungers, then the pump will suck air and/or leak water.

The small cheap ones that have the unloader as part of the pump are the worst for this. Ones with a bypass hose can be ran through a cooler if you want to leave your machine running in bypass a long time.

 

[Kendog 170]

I had a craftsman that had a couple of broken springs. Someone threw one in the trash with the same issue. Had enough springs to get it going again.

 

[ProjectBazza]

The small cheap ones that have the unloader as part of the pump are the worst for this.

Like this one?

Comet AXD2530:

Thank you for chiming-in on this thread!

 

[LO23M8B]

I just bought a new one just got tired of messing around with them. $200 plus 50 for shipping 3900 psi works good. From walmart.

 

[jeff alder]

You could add a cheap wye strainer to your supply for the power washer...in addition to having the actual screen on the machine. Peace of mind and ez to clean.

 

[Demonx2]

I've had a cheap big-box store Toro brand one for about 15 years. I've always run water to it and pull the trigger for about a minute prior to starting the engine. This seems to purge air out of it. Then I start it, let it run for a little bit, pull the trigger and go. If I don't do the pre-routine, it will sometimes not switch to high pressure when I pull the trigger. Or go back and forth between high and low/no pressure. The unit I had prior to this one acted the same way.

I do the reverse when I shut it off. Keep the water turned on and pull the trigger for about 30 seconds to help cool whatever parts touch the water.

Just used it last week for the 1st time in about a year. No start. Had to pull the carb, clean it, and reinstall. Then it fired right up.

Works for me!