Karcher K5.91 not lifting detergent

[GezT]

Hi, can anyone help me resolve the lack of venturi effect on my Karcher K5.91, I have stripped the venturi valve down and re assembled it, checked the poly tubes for blockages and leaks, but it still does not draw any detergent from the reservoirs, the machine is new but no warranty exists.

 

[jj4091]

Probably a daft question, but have you got the lance switched to low pressure?

 

[GezT]

Hi JJ, yup I've tried that, have waited for about 2-3 minutes with trigger depressed to see if that will prime it, but to no avail !!
But thanks for that, I will try just about anything right now

 

[jj4091]

I think my next thing to do would be to try & borrow a lance off someone else, as that is the only thing I have ever had a problem with on them.

 

[GezT]

Thanks JJ, I will try your suggestion.

 

[jetwashking]

the venturi only works at low pressure so remove the gun and pressure hose from the machine open the chemical valve (if fitted). turn on the the tap and switch on the machine. the chemical should come out of the machine and sudds would be on the floor of your yard. if this works the gun or lance are not dropping pressure. try again with just the gun but no lance. if this still works its the lance. if this has no chemical then the venturi may still be ok but the non return valve in the chemical hose connection tail barb maybe stuck. a ball bearing pressed into an oring. parts can be bought online from sites like sparesgiant