Clean and unloader valve on Karcher hd3500 pressure washer -intermittent pressure on and off. Cleaned inlet screen. Think unloader valve is is under pressure knob? Will cleaning help?

I have same model with same problem. Tried the easy fixes:
unloader valve lube and clean, inlet water sufficient, and nozzles and hose are fine. Broke down pump and called for parts (about $50 for 3 inlet valves and some seals) hopefully this will fix it. Mine has been used in my business pretty hard for a few years, so not bad.
Joebro

If this hole has threads then it might be the soap inlet. If water is shooting out under pressure you may have an obstruction in the hose/handle. Try removing the hose and running the washer and see if the water flows out the connection. If the hose ends up being the problem a visual inspection and cleaning of all inlets and the handle should clear it.

If the water coming out of the hole is low/tap line pressure then I think your bypass *(or unloader) valve is stuck in the bypass position.

A stuck unloader just needs to be unstuck and lightly cleaned. A light coating of silicon grease wouldnt hurt either!

Get the manual for this pump and see how to open/remove the unloader valve.

hi there rjcomer2

here is web site for parts
http://www.ereplacementparts.com/karcher-2500-11944010-pressure-washer-parts-c-33388_33389_33973.html

sounds like you have a unloader valve problem or a crack in the pressure manifold housing between pressure outlet and unloader valve assy allowing unloader to cycle on/ off

or some dirt trapped in the unloader valve seat , make sure you have good supply of water - ie good flow from tap to pump

try cleaning unloader 1st and fitting in line tap filter

hope it helps

pauly46

Yes, the unloader needs to be lubed. Send me a email at [email protected] with a discription of what you just listed and I will send you a pdf file on how to repair it.

Before you do the below steps check the water supply inlet screen for obstructions where the water hose connects to the unit. If you notice debris remove and clean the screen under running water with a small NYLON brush.

The bypass unloader valve is triggering earlier than it should. You can lubricate this by adding oil to the water supply inlet (at least 3 oz.) and very briefly switching the unit on then off 0.5 seconds. Then let is sit overnight. The next day connect power briefly and again cycle the unit on then off for 0.5 seconds. Connect the water supply and then purge the water wand hose into a bucket to catch the oil before use. After this restart the unit and operate the wand trigger under full pressure at 0.5 second intervals to ;scycle the bypass / unloader valve inside the pump. This method has worked in about 95\0 % of the machines I have worked on. The oil lubricates and fattens the seals in the bypass / unloader valve. It eihter works the first time or the seals are torn in the unloader valve and must be replaced. With only 3 uses I think your pretty much in the clear and will not need new seals.

Thanks for using FixYa.

Kelly

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

The Karcher K2400HH and G2400HH do not have an unloader valve, they have a spill valve which is located under the black cap on top of the pump.

The spill valve needs to be removed and the side walls of the hole it sits in need to be wire brushed to remove deposits. then you can put it back in and put the pump back together.

Hi
The unloader valveis HERE
If you go to D-2 it is part numbers 8 to 13. If it is stuck it is not only important to free it up but also make sure no o-rings are damaged and lube it with a very good waterproof grease. Good luck.

i had this same problem on my pressure washer.the pump had some broken parts in it .i found my replacement pump on EBay.

could be allsorts. seals worn. ceramic pistons split, inlet manifold split( frost damage), unloader valve sticking, etc etc.

Put mains water pressure onto it and look for leaks, then run machine and see if it increases pressure, if not i would suspect unloader valve sticking.....

Not very familiar with the 1050 but i'm a service engineer for high press cleaning equipment...