Who works on power washers?

[guy48065]

The pump on my power washer was leaking & not making pressure so I installed new seals, pistons & a new regulator. No more leaks & makes pressure but it doesn't feel like as much as before so I installed a gauge. On a Youtube video the pressure drops to a few hundred psi when the trigger is off, and climbs to max right after you pull the trigger. "Unloader valve". Mine is not doing this. It stays at 3200psi and when I pull the trigger it drops to 1500 or so and maintains that. Adjusting the regulator will drop the 3200 "stand-by" pressure but when the trigger is pulled I still get the 1500psi output.

Did I buy a dud regulator or is there something else wrong with this pump?
Engine RPM is solid and the pump is an Annovi Reverberi XMV 4G32.

 

[SGKent]

when I've had pump problems I've just replaced the whole pump assembly. The ones I've had were filled with electrolysis even though they are drained each time. The first pump I bought was at about 7 years - the dealer told me 2 - 3 years between pumps is common. A quick google came up with this. There is an attached forum.

https://mastertoolrepair.com/industrial-triplex-plunger-parts-xmv4g32-p-686892.html

 

[guy48065]

I've already got enough $ into the rebuild that I could have bought a new pump. Hindsight, you know...

Hoping someone here knows more than I do about these pumps & what might still be wrong with mine.

 

[gungatim]

yeah I just bought a replacement pump for a craftsman unit right off amazon. generic replacement was <$100, the customer wanted "factory replacement", so paid $150 for the superseded sears part number (after a little research or searspartsdirect), although they are pretty much all the same. just make sure it is the same psi, bolt pattern, and crank diameter, which most of them are. some have a little taller housing so make sure it clears your frame (if vertically mounted), but they usually still all fit the motor...

I've not found any homeowner grade pumps worth rebuilding...

 

[guy48065]

Cheapest replacement I've found for my 3200psi 4gpm pump is $260.
You can buy a lot of replacement parts for that $.

I watched another video on YouTube that seems to indicate that my pump is acting normally.
Conflicting information on the internet seems to be the norm.

 

[gungatim]

well a cheapo replacement pump is $88, you could go that route and live with a 3000 psi unt, as I see the actual pump you have is $269 and appears a better pump.

the unloader for that is only $$35, it may be the unloader is bad?
https://www.amazon.com/dp/B01AGWM3II/?tag=atomicindus08-20

 

[sberry]

Something is wonky with the unloader, not sure if they have a check valve that may be trapping the pressure between the pump and gun at idle? It seems like it would stall it if the unloader isn't working unless it is being bypassed thru the pressure relief?

 

[guy48065]

New unloader was $94 for the correct one for my pump. AR XMV pumps use banjo fittings to mount the unloader so that limits replacement options.
After watching a couple more videos I believe the unloader does have a check valve and my gauge is showing the pressure that's trapped in the hose--not the actual pressure inside the pump. When I release the trigger the engine rpm increases so I'm pretty sure the unloader is doing its job.

Now I have to figure out why I'm only getting 1800 max psi with gun on. I didn't realize there are a wide variety of tip sizes out there--not just the "one-size-fits-all" set that came with the washer. I might be able to get correct pressure if I get tips that match my pump flow. I also need to try a short fat hose to make sure my garden hose reel isn't limiting GPM, which would also explain my lower pressure.

OTOH the pressure I'm getting right now is definitely enough for washing cars & siding.

 

[sberry]

I doubt the hose reel is a problem. It would be sucking the hose in if it was and this is likely under 3 gpm. You might be able to take unloader apart too, that stuff all gets stuff stuck in them and often a cleaning makes them work again. I took a regulator apart the other day, the seal was fine, it simply had some buildup causing it to leak.

 

[MikeF2316]

Yeah, I get the feeling that pressure washer pressure specs have as much basis in reality as shop vac hp or printer page per minute.

 

[PeterT]

I've got a honda pressure washer that's sat for a couple years, it starts but as soon as I pull the trigger it dies out. Maybe the carb, needs cleaning, I wonder if that 'VP mechanic in a can' fuel would clean the carb out w/o me having to take it apart

 

[Cf mtn]

New unloader was $94 for the correct one for my pump. AR XMV pumps use banjo fittings to mount the unloader so that limits replacement options.
After watching a couple more videos I believe the unloader does have a check valve and my gauge is showing the pressure that's trapped in the hose--not the actual pressure inside the pump. When I release the trigger the engine rpm increases so I'm pretty sure the unloader is doing its job.

Now I have to figure out why I'm only getting 1800 max psi with gun on. I didn't realize there are a wide variety of tip sizes out there--not just the "one-size-fits-all" set that came with the washer. I might be able to get correct pressure if I get tips that match my pump flow. I also need to try a short fat hose to make sure my garden hose reel isn't limiting GPM, which would also explain my lower pressure.

OTOH the pressure I'm getting right now is definitely enough for washing cars & siding.

when you test your pressure you use the 0deg. tip
.youtube.com/watch?v=s2B3u025HTw

 

[sberry]

I've got a honda pressure washer that's sat for a couple years, it starts but as soon as I pull the trigger it dies out. Maybe the carb, needs cleaning, I wonder if that 'VP mechanic in a can' fuel would clean the carb out w/o me having to take it apart

Learning to field service a carb is a real life skill. It takes an extra few minutes if they are virgin but can do most in a few minutes. Compressed air is about a must.

 

[Packard V8]

I've got a honda pressure washer that's sat for a couple years, it starts but as soon as I pull the trigger it dies out. Maybe the carb, needs cleaning,

If it's like many Honda carbs, you'll need to make studs to get it back together. Often, there's a spacer, a heat shield, the carb, a gasket and the air filter base, all held on by the carb bolts. Almost impossible to get everything aligned without at least one stud. It's possible to use smaller diameter unthreaded rods, but threaded is better.

jack vines

 

[Heavy Metal Doctor]

I work on much bigger systems all the time. Unfortunately, my experience has been that anything below about 12 GPM at 3000 / 4000 PSI is pretty finicky and pretty much throw away stuff. I'd go over and it give it shot if I had access to it, but pretty hard to just say what your particular problem is by description of symptoms. In general, when an unloader won't shift into dump mode and all the ports are connected where they should be, then the shuttle inside is screwed up somehow. The will also act like a regulator and just hold pressure if not adjusted correctly.

 

[Wamsutta]

There's a member named fatfillup that works on power washers. PM him.

 

[brilliantv]

Hi, I own a pressure washing business. The final pressure is determined by the orifice size of the tip. To learn more, google pwra (pressure washing resource association). Its an online forum like garage journal except for pressure washing. Use the search bar for any question on tip sizing and a thread should come up with charts.

 

[goodwrench]

the tip is ultimately what sets your pressure with the trigger pulled!! if your gauge reads max pressure with trigger not pulled, that means atleast under no flow the pump can attain full pressure, that the unloader/regulator is working. when you release the trigger does the motor load up, then sound like it has less load? if so the unloaded is probably working, when they fail, either the engine dies or it loads down hard when the trigger is released. the tips do wear the orfice bigger with use, which passes more water which means lower pressure. the pump has a max flow, the tip too big passes more water, so less pressure. tip too small will build full pressure but at reduced flow, the excess being recirculated by the unloader/regulater. there are charts online to find your tip size. you must know how many gpm your pump flows, and the rated pressure. hope this helps you out.

 

[guy48065]

Good weather over the weekend so I got to fiddle with it some more. I'm pretty sure everything is working like it should. I set the regulator to 3000 with the trigger off and am only getting 1800 (with 0° tip) while spraying, with the regulator knob hitting the stop (which is adjustable). I don't think adjusting it while "off" is correct. From what I've seen on videos the pressure I see when the trigger is off is a spike that's trapped in the hose. My assumption is it can peak beyond the pump rating & not hurt anything. I'll need to take the regulator knob off & see if I can adjust the flow pressure closer to 3200 and just see what that "off" pressure spike ends up at. I won't be comfortable if it goes above 4000 so I might end up at a compromise pressure less than pump rating.

If I understand what's going on that "off" spike is only in the hose, trapped between the check valve and trigger, and the pump doesn't see it.

There's a bit more going on in a power washer than it appears. I had no idea till I plumbed in a gauge.

 

[driz]

I've got a honda pressure washer that's sat for a couple years, it starts but as soon as I pull the trigger it dies out. Maybe the carb, needs cleaning, I wonder if that 'VP mechanic in a can' fuel would clean the carb out w/o me having to take it apart

Likely ethanol corrosion in carb. Do what I do put a shutoff in-line do you can always store it dry OR no more booze gas.
For your carb now Seafoam maybe........ then if that doesn’t work check for the numbers on the side of the carb. Start googling those with replacement carburetor. I’ve found that in the last 10 years there are replacement carbs for a song. The last 2 I bought were <$13. Stick it on and go. I never even needed to adjust them . For that price it’s not worth the hassle of teardown and cleaning . Save old one for parts. So simple...[emoji847]. Same goes for pumps. <$100 ,stick on and go......


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