Unit pressurizes then unloads over and over again with green tip, with red works perectly

I got this about 10 months ago went to wash my deck and no pressure not been used a lot but not happy with this

Sounds like the unloader valve built-in to your system is sticky. Try lowering the pressure of the regulator to lowest setting then re-adjusting. This will place a different pressure /load on the valve. Also when you store your unit, displace the water in the pump with oil so that lubricant will prevent the unloader from sticking. If you continue to have problem, replace the unloader. Good luck

Assuming that you have a pressure gauge to determine actual system pressure. Without pressure gauge, you could use the sound of the engine as test for capacity pressure (if engine and pump are paired correctly, engine will labor at full throttle under high pressure). Using your machine at rated capacity will decrease the life of the unit. Better to use at 75 ~ 80 percent of cap. (2500psi on your unit). Pressure is developed thru the restriction of the tip/orifice assuming that the pump is working correctly. Tip should be correct for the capacity of the pump. Check the pump capacity for gpm (or test by removing tip connect water supply, then with engine running, catch water in bucket for exactly one min. and measure quantity). Example, 4 gallon per minuite should use a tip with 4gpm markings. If wrong tip size is used, (too large, low pressure, too small, pump will go into unload condition resulting in low pressure) . If thru testing you determin that the correct size tip is installed, suspect valves or unloader. Leaking valves or orings that seal valves will cause low pressure and also cause a pulsating sensation. Worn unloader will cause pressure to rise and fall in a slow cycle. Good luck with your repair

Hi again and thanks for your response. If the engine is coming under an extreme load the unloader valve is stuck in place. Since the unloader valve is on the bottom of the pump it stays wet all the time and when in not in use the metal parts of the valve corrode as will the brass parts of the pump housing.
The unloader valve is on page B of this link: (Item A)
http://www.ereplacementparts.com/troybilt-0203370-2550-psi-pressure-washer-parts-c-26780_27006_25694.html

The following steps are hard to perform without causing havoc with your engine due to tipping so, what I am recommending is that you do NOT tip the engine to perform the following procedure without any dis-assembly of your unit at this time:
- IF you have a very short garden hose like the one that would go to a hose reel or a washing machine hose. Use that hose for this procedure over night. Connect the short hose reel or washer hose to the water supply connection of the pump and also connect the high pressure hose to the pump. Pour about 5 oz of regular engine oil into the water supply hose and tie the hose so that it is elevated (to retain oil in pump) Keep the high pressure hose elevated also so that the hose does not drain oil the oil you just added from the pump. After a few minutes with the engine ign. OFF pull the engine through 2 times. Let is sit over night. (What your trying to do is lubricate the seals and hopefully loosen the grip of any internal corrosion in the unloader valve area.)
The next day... after no more than 24 hours. Connect the short hose to a real water supply and start your pressure washer. once started do VERY short bursts with the wand trigger (1sec bursts rapidly). Your trying to force the unloader valve move and cycle normally in the pump housing. REMEMBER you added 5 oz of oil yesterday to the water system so be careful where you spray the first bit of stuff coming out of the wand nozzle. Keep up this 1 sec burst cycle going for 2 to 3 minutes or if begins to work normally your done and it is time to tidy up. .

If this did not work.... (it does about 85% of the time)
- You will have to remove the unloader valve and clean it.
Once removed try to get as much stuff off of the spring and o-rings as possible.
- Also you will need to clean the pump housing where the unloader valve installs.
- INSPECT all of the o-rings for cuts and again carefully wipe them clean so as not to damage them.
- BEFORE you reinstall the unloader valve you will need to lubricate the pump housing and the unloader valve with "White Grease" (Auto parts stores have small tubes of #105 white grease) Don't be afraid to use liberal amounts of white grease.
- Re-install the valve and test
This should bring your pressure washer back to normal again.

Let me know how things went.
Kelly

Most likely problem is that the tip is too small causing Unloader to bypass or restriction/debris in tip. Install clean tip of proper size or 1/2 size larger (example from 2.5 gpm to 3 gpm ) to prevent slow pulse. If tip is clean and /or larger tip does not help, Unloader may be failing if the unit has a good deal of hours or if machine is left running for long periods of time without spraying. Try lubing the internal parts by removing both hoses and installing a short piece of water hose to intake and slowly inject light oil into pump by pulling on the rope slowly to **** in the oil until it comes out the pressure side. This will displace all the water from inside the pump. Leave overnite. There is a kit sold on ebay to help facilitate the infusion of oil but no need to get fancy. Unloader repair kit is usually available if all else fails and is easy to install. Good holidays

Whar has happened is that your unloader / bypass valve is sticking. This is due to minor corrosion and having water in the unit over the winter. Most of the time they will sanp out it if you do the following:

Add 3 - 4 oz of oil into the water supply connection and briefly and I mean very briefly switch on the unit then right back off. Add more oil to the water supply connection and then let it sit overnight.

Then next day turn the unit on briefly and let it sit another 30 minutes. After this you connect all hoses making sure to purge the air our of the supply hose BEFORE you connect the to the unit. Then once you turn the unit on rapidly trim cycle the wand trigger. Your goal here is to cause a water hammer of the unloader / bypass valve to get the spring and cupped seal to move in the housing. Pause briefly and see if pressure builds then fan the wand trigger again. This can take a few minutes to get it to work but the routine of pausing waiting momentarily and rapidly tripping the wand trigger is what should get the unit going again.

If this does not work you will have to take the unit apart dis-assemble the unloader / bypass vavle on the output side of the pump and remove the corrosion on the spring and the housing.


Once your done cleaning up the bypass unloader valve before you put it back in the housing place a liberal amount of Lubriplate #105 White Grease on the spring and inside the housing on the mating surfaces. (#105 white grease is available at any Auto Parts store. It is in a 3 - 5 oz plastic tube)

Re-assemble the unloader / bypass valve an it should work like a champ.

Thanks for choosing FixYa.

Kelly

Most likely problem is that the unloader is bypassing water. As unloader wears it will by pass at lower pressure. Try lowering the pressure at the regulator to lowest setting then raise pressure a little at a time untill unloader releases then lower to prevent unloading. Using a slighly larger tip will do the same thing. Using a larger tip size lowers pressure.

I have the same problem. This is the responce for Karcher......

The unloader valve may be sticking, or is dirty. It probably needs to be cleaned and may need to be replaced, it is inexpensive. It gets a lot of use, but extends the life of the pump. The function of the unloader is to allow the machine to run in a bypass mode while the trigger of the gun is closed. First, a lack of high pressure can be caused by: 1. Insufficient water feeding to the unit, so check that the water is turned on all the way and that there are no kinks in the hose. 2. The inlet filter may be clogged. (it will need to be removed and thoroughly cleaned). 3. An internal water leak. 4.Also, low pressure can be caused by worn spray tips. If you have checked the first three with no resolution, the problem is internal and could be as simple as a sticking unloader valve. If you are mechanically inclined, you can clean this valve yourself and greasing the o-rings (use lithium based grease), or take it to a local service center. You do not need to take the pump apar
t. The unloader valve is located under the cover, and is secured with 2 bolts. (Use needle nose pliers to remove the valve) For those units with pressure and volume controls, the unloader is located under the pressure and volume control knobs themselves. Do not take any other bolts off or you will open the pump and lose the pump's oil.

Note: Lithium based grease will prevent future failure of the unloader valve.

Also, check websites such as fixya.com for tips and how-to info particularly on cleaning the unloader valve. Be sure to use lithium grease if you reassemble it.
I am going to check the manuel to see where it's at

With the water on, to the washer and the unit running. Does the water come out at the same rate before the trigger as at does after the trigger (run test with spray nozzle removed). Its not impossible for unloader valve to be bad but it usually is a dependable component. Make sure the unit has the air purged from it properly before start-up, make sure there are no obstructions before the trigger, then the nozzle. The unloader valve just puts the pump into by-pass until the trigger is depressed.

It sounds like your intake is plugged with debris. What usually happens is a water hose that has been laying around will get various stuff in it -- dirt, grass clippings, small insects (and whatever they take into it nest building). These days most homeowner pressure washers do not have a proper inlet filter, but just a screened hose washer like on a washing machine. The unloader valve can cause pressure variance, but usually not in the manner that you described. The pump is being "starved" for input water. Just use a pair of needle-nose pliers and pull out the screen and clean it or replace it.