[gwrightson]

I have a Honda techclean pressure washer , I have found the pressure is dropping quite drastically, I have checked for blocked filter, that is fine and I had all new seals etc replaced late last year so I am guessing could be uploader valve    Some times the pressure is fine then after 2 or 3 minutes it loses pressure!! 

I set the valve so it was fully open so no pressure to speak of at all then turned the valve fully to attain as much pressure as possible this worked for a litlte while m then the same thing happens.
Do you think the valve is knackered or can it be repaired ?

Geoff

[BDCS]

Remove the return to tank and with the trigger open is there any return, this indicates if the ULV is bypassing. This could also be caused by a blocked nozzle.

[gwrightson]

I will try that thanks,  I was using a turbo nozzle at the time, seemed to be spinning ok.

Geoff

[BDCS]

I assume you don't have a pressure gauge on the machine the unloader should be set just over the pressure developed whilst washing. If you have a grain of sand in the nozzle which partially blocks the nozzle it will in effect be like running a smaller nozzle which in turn ups the pressure causing the ulv to dump excess pressure to tank. First try your fan nozzle and watch the RTT for flow. Tech clean fit a QR on the RTT so its easy to drop it off and check for flow. I change the ULV when I change valves