North Star Power Washer problem

[johnnylight]

North Star Pressure Washer problem

I have a North Star power washer model 1578961A it's a 8HP power by Tecumseh with annovi reverbersi pump


My engine runs with no problems.

here's the problem:

no pressure to wand.


What I have tried so far:

Replaced spark plug.

replaced a 3000psi wand with a 4000 psi wand. (it was the only kit I could find at the time worked for awhile before all this started.

checked the unloader valve put it back together and it work until I released the trigger. The pressure would not come back.

I held the adjuster to give her more rpms and she worked this was short lived it will not do this anymore.

while she was working with raised rpms I messed with the unloader adjustment knob to lower psi and that's where it ended.

Based on the suggestions from the other power wash post it looks like my unloader valve is the problem.

where can I buy one?
Is it the wand difference in psi?


What do you think?

 

[Hooked_on_HP]

Is there a chance your pressure washer has a screen on the inlet(where the garden hose hooks) that is pluged. With the engine shut off and the high pressure hose unhooked turn the garden hose on and see if you get flow through the pump. If you do it is a releif problem and if you dont you have a restriction on the supply side.

 

[johnnylight]

Is there a chance your pressure washer has a screen on the inlet(where the garden hose hooks) that is pluged. With the engine shut off and the high pressure hose unhooked turn the garden hose on and see if you get flow through the pump. If you do it is a releif problem and if you dont you have a restriction on the supply side.

Thanks
water is flowing, what kind I do for the relief problem?

 

[CCWKen]

Take the unloader valve apart and clean it then lube with some white grease. They're pretty simple. Most are just spring loaded telescoping slider valves. Mine gets used about once a month or less so the standing water caused some corrosion. I cleaned mine last year and it's good as new.

 

[johnnylight]

Take the unloader valve apart and clean it then lube with some white grease. They're pretty simple. Most are just spring loaded telescoping slider valves. Mine gets used about once a month or less so the standing water caused some corrosion. I cleaned mine last year and it's good as new.

Thanks

When I had the unloader valve apart I noticed dark stains on it.
The knob is hard to turn so the grease sounds like a good idea.

Any suggestions on where to buy a unloader valve or replacement parts if needed?

 

[bob_wood]

Thanks

When I had the unloader valve apart I noticed dark stains on it.
The knob is hard to turn so the grease sounds like a good idea.

Any suggestions on where to buy a unloader valve or replacement parts if needed?

Northern Tool has unloader valves.

Bob

 

[johnnylight]

Northern Tool has unloader valves.

Bob

Thanks Bob,

Glad you were able to get yours up and running.
I clean up the unloader valve grease it up nice the valve turns with ease but still no pressure.

How do you know when the pump is bad?
What should I try next?

 

[Gnash]

If you have a trigger gun with removable tip, take the tip out and try your machine. If you have a good stream of water, clean tip, replace and and all is well. If there is still no flow through the gun, remove the gun itself from the hose and try again. ( You see the pattern here? ) Still nothing? Remove the unloader valve and try it. If after all this,( about 15 minutes ) you still have no flow, you probably have a stuck valve or valves in the pump. Not difficult to fix at all, but try these things first and if need be I'll explain how to do the valves.
Gnash

 

[johnnylight]

If you have a trigger gun with removable tip, take the tip out and try your machine. If you have a good stream of water, clean tip, replace and and all is well. If there is still no flow through the gun, remove the gun itself from the hose and try again. ( You see the pattern here? ) Still nothing? Remove the unloader valve and try it. If after all this,( about 15 minutes ) you still have no flow, you probably have a stuck valve or valves in the pump. Not difficult to fix at all, but try these things first and if need be I'll explain how to do the valves.
Gnash

Gnash (cool idea process of elimination)
Here's what am up to: water runs through steady stream of water same as hose pressure but no pressure from pump.

I removed the valve body allen screws and found 2 valves equal distance but the 3rd valve is out a little further.
Thanks for the help.

 

[johnnylight]

update:

Valves are moving ok - I can move them by pulling crank.

Well I was able to clean up my tractor, I bought a troy built 2550 psi with car kit turbo nozzle, and rotating brush for $50 at a yard sale. (It's never been used)

Obsering the new power washer I can see the unloader valve spring suck in while the trigger is pulled --this is something my northstar is not doing.


I keep you posted am not giving up, just needed a working power washer right away.
thanks for all suggestions including the other power washer post (JJ) about the unloader valve very informative.

 

[Gnash]

Johnny, What you are describing are the plungers, not the valves. The valves are located under those big brass caps with hex heads. If your pump is a triplex, it has six of these caps and six valves. The three located on the front of the pump are intake valves and the three on top of the pump are the high pressure valves. If there is trash in any of these valves your pump will not be able to work properly. If any of them are stuck closed, your pump has problems also. Since you have very little flow, I would look at the intake valves first. The valve itself is two parts, both of them stainless steel, held in a plastic cage. There is also a spring in the cage which closes the valve. Now to check and clean them. Remove the brass caps and pull out the valve cages with needle nose pliers. Now look carefully at the valve, checking for any little piece of trash lodged between the two valve parts. It is critical that they are completely free of trash. If you find nothing, then make sure they are not stuck in place, (shut), by opening them manually. When you are satisfied they are clean and moving freely, replace them in the pump and try again. If necessary, do the same for the high pressure valves on top of the pump. Good Luck.

 

[johnnylight]

Gnash,

Thanks for that info I'll work on that tomorrow since I already have it off it should be easier to work on.

I'll post some photos.

 

[JB4310]

I had the exact problem your describing with two of my washers, one was the unloader valve dirty and one yesterday was just a missing o-ring in the tip coupling on the wand, only figured that out after I took this unloader all apart. any loss on the high pressure side before it comes out the metered tip will drop the pressure way down.
I have a pretty expensive commercial duty one with a Honda engine and a cat pump that is very sensitive to the high speed engine rpm, if it's off just a little the pressure drops way down as well.

 

[johnnylight]

JB4310,

Thanks I'll try that next.


Gnash,

I didn't find anything all clean out.
here's some pictures:

 

[johnnylight]

Just got off the phone with North Star and they don't make this unloader valve anymore.
Am going to try replacing the washers from the local hardware store.
I'll let you know if it works.

 

[johnnylight]

update:

JB4310,
I checked the o ring is there.


I went to a Plumbing supply house --no good.
Pick up a oversized washer from the hardware store, amd tried to match it to the old one so I can cut it to size it came out ok.
I could not replace all washers--it's just the way it's made.

So I Put all back together and it worked released the trigger and that was it the pressure was gone again.
The pressure is a little stronger.
So am convinced it's the unloader valve.

Now it's time to find one.

 

[bob_wood]

Just got off the phone with North Star and they don't make this unloader valve anymore.
Am going to try replacing the washers from the local hardware store.
I'll let you know if it works.

they probably Do have an unloader valve that will work but you will need to buy a few extra fittings to adapt it to your machine. They can supply the fittings. what you have in the pictures is exactly how mine looks inside.

bob

 

[JB4310]

I'm by no means an expert but I do have 2 pressure washers, they can be a pain, one is very old but was a commercial duty unit, the newer one is commercial quality also but both have given me trouble.
Yours does sound like it's in that unloader assembly, maybe not necessarily with the plunger that you show in the picture but inside where the little ball seats.
Like I said both mine did the same as yours, with the newer Honda powered unit it was a combination of a poorly seated ball in the unloader and not high enough rpms on the engine, and on the old one just yesterday it was the o-ring.
Do you have any other leaks when you pull the trigger and also do you have the correct tip that came with the machine, if the tip was for a higher GPM machine then you would lose pressure

This is a picture of my old M-T-M which I just put on Graigs list, no one wants to give me even $150. for it. I know it's ugly but it's been working for over 20 years, probably cost over 2 grand when new.

Good luck, JB.

 

[johnnylight]

Gnash,

Your suggestions are exactly what the people from North Star tech support said to try
and thanks for the help.

Everytime I mess with the unloader valve it will try to work so I found and ordered one at Karcher Pressure Washers, Karcher Parts, Karcher Accessories, Karcher Power Washers and Pressure Washers should take about a week to arrive.

I never put a dime in to this pressure washer so it's worth a shot.

I'll keep everyone posted how this turns out.

 

[johnnylight]

UPDATE:

Installed new unloader valve works great.


Thanks to all.