Was given the K4 full control as a present, as my K2 packed up after 4 years. Was happy with the K2 until I used my new K4. Well worth spending a bit extra as this unit is fantastic. 9M pressure hose makes a massive difference and the 2100 PSI is superb. I already had the foam bottle for my car and the premium deck and patio cleaner so prefer the K4 to the K5 & 7. I love keeping my car in showroom condition and it is a pleasure using the K4. Also have extensive decking in our home and the deck cleaner makes it easy to maintain. Cleaning the pavement outside my home is a breeze. Highly recommend the K4.
PS. Make sure you run the water thru the gun for at least 20 sec before turning on the motor.

Total crap first time I tried to use it the lance wouldn’t go into the gun handle so I rang Karcher & guess what they are having issues with the K4 pressure cleaner handle, they were nice on the phone & organise a new handle/gun to be sent out after a week or so it arrived & yes it works BUT I tried to wash my car & used Karchers foam gun & it’s starts to leak everywhere I just couldn’t be this unlucky, now I’m waiting on Karcher to get back with some information it’s so frustrating especially when I’ve spent nearly $500 cash on this unit & really I can’t use it buy some other brand don’t buy Karcher!!!!

So this will be my third Karcher Pressure Cleaner. The previous two failed after a year or so and after multiple trips to the repairer gave up with both. (pump failed 3 times on one and the other one kept springing leaks which turned out to be cracked internals). Now I don't given them a hard life. the car from time to time and the, drive and gutters may be once a year. (none have ever made it beyond 2 years). This top of the line machine had a pump failure 18mths in and is in for repairs now. Absolute rubbish and the last one.

If you like assembling cheap and nasty Leggo kits then the K4 is for you!

Click, push, click, push as it goes together! It feels like plastic junk and that's what it is!

The roll up pressure hose is something from your worst nightmare as it twists and snarls no matter what you do.

After 12 months expect bits to start breaking off and the pressure lances become impossible to get in it out. They also clog up so you have pull them apart an clean them.

The wheels will seize up after about six months ........

A complete heap of cheap and nasty plastic, don't touch it!

Purchased this 2 years ago from Bunnings. Used it 4 times and lo and behold ......leaks from the pump unit. It’s out of warranty so not much choice to either pay Karcher to fix it or assign it to the scrap heap.
I would suggest that now this is my second one that leaked ....That there is a design fault with the model.