I have a karcher G 2500vh and when engine is running with water hooked up, a pressurized leak comes out of the back of the pump. When i squeeze the trigger there is very little pressure coming out of the nozzle for a couple seconds then seams to work but the leaks pressure gains as well. how do i fix this?

It sounds like there may be a potential issue with the pressure build-up mechanism in your Karcher K2 compact. The constant motor running without water pressure could indicate a problem with the pump or the pressure switch. I would recommend checking the following:

1. Check the inlet filter: Ensure that the inlet filter is clean and free from any debris or blockages. A clogged filter can restrict water flow and affect pressure.

2. Inspect the nozzle: Make sure the nozzle is not obstructed or damaged. A blocked or damaged nozzle can restrict water flow and affect pressure as well.

3. Check the pressure switch: The pressure switch is responsible for regulating the motor and water flow. It's possible that the switch is faulty or not functioning correctly. Consider contacting Karcher customer support or a professional technician for assistance with checking and possibly replacing the pressure switch.

4. Examine the pump: There might be an issue with the pump itself. It could be worn out, clogged, or experiencing other internal problems. In such cases, it's best to reach out to Karcher customer support or a professional technician for further diagnosis and repair.

Remember to always follow safety precautions and consult the user manual provided by Karcher for specific troubleshooting steps and guidelines.

Getting to much air to carb probably.

For item 5, I would check the Detergent Injector, water should never come out there, Maybe something (dirt) is causing it to malfunction.
see picture here http://www.ereplacementparts.com/spare-parts-kit-p-482334.html. Check the ball, o-ring and spring... leakage like this would be one reason for no pressure, It's like not having a nozzle on. fix the leak at the quick connect as well, check the o-ring and replace of it is hard and brittle or nicked. tighten the connection if it is leaking at the threads, some thread sealer sutiable for 2600PSI maybe.
Engine surging problem 'may' go away once you get a proper load on it...

If this is a new pump contact the supplier, maybe it is defective.

DISCONNECT HYDRO OR WITH ENGINE NOT RUNNING DISCONNECT SPARK PLUG THEN RE-LEAVE WATER PRESSURE BEFORE SERVICING the detergent pipe plugs into a pipe on the pump, under which is a spring and ball bearing (stuck open, debris) WEAR YOUR SAFETY GLASSES

Disconnect hoses.
Look for kink in water hose.
Check incoming water connection for filter washer
Replace filter washer
If you don't have a filter washer, put one in.
Hook up water, and turn on
Water should come out other side of pump.
Turn on machine.
Do you get pressured water out of pump.
If no pressure, then pump is suspect
Hook up washer hose without gun
Does pressure come out of washer hose
Finally, the gun trigger may be bad.

We had to buy guns now and then.
Search for pressure washer guns
Following link shows guns we used:
http://www.ultimatewasher.com/pressure-washer-trigger-guns.htm

Hi This could be just the water inlet channel broken or split. You will need to remove the yellow cover via the screws at the back of the unit and then connect the water hose to see where the leak is coming from. If the water comes from underneath the pump then you will need a replacement pump seal kit of which you can purchase on the Internet.

This may not be a motor problem. It sounds like your pump is not working properly and the motor is just following the pump. First thing to do is check for leaks in the pump, wand hose, gun etc. It may also be a blown water seal inside the pump.

Is the tip/nozzle clean? try a different one. But you're probably right about the pump (I think they are all junk) unless you spend over a grand and get a "real" one

what you need to do is, take the screw fitting which goes to the water tank off, then the one that goes from the water tank to the pump head .
then put the one that was in the first place going to the water tank on to the pump and force feed with water.
see if you can see water leaking from any where seals hose.
try running the machine to check the pressure.
if water leaking from pump head you need seals.

I have a Karcher K 3.86 M electric PW with a similar problem: water leaks from the pump near the outlet and the pressure surges on and off continuously at intervals of 1-2 seconds. The leak appears to be coming from a very thin crack in the plastic pump head in what I think is the "unloader" valve portion. I read elsewhere that if you leave water in these PW's and it freezes it will crack, causing leaks. I don't know how you can empty all the water out so I think we must store these PW's in areas that won't freeze in winter.