Small Engines (Lawn Mowers, etc.): pressure washer pump, ill check, pressure hose

Question
i have a loncin pressure washer,9hp 3600 psi,its about a year old,always worked fine until now,i was using it the other day,it was working fine for about 20 mins,i put the lance down to move a car (didnt turn off washer) and when i picked it up 2 mins later i only have about half pressure and a slight vibration through the lance..no strange noises from engine or pump.,changed nozles to no affect,disconnected hose and gun from pump,ran the water through it then started it and there doesnt seem to b much of a difference in pressure,also i noticed when the hose and gun is disconnected the adjuster (between the pump and hose/gun) does not seem to be working..not sure if it does then the hose is on..ill check now..thanks in advance

Answer
hi    gerad


sounds like the unloader valve my be stuck / or sticking  causing a a slight vibration in the pressure  hose -by trying to cycle  while trigger is closed .  is the water supply pressure good in your area  ?  and is the inlet water filter clean  ?

check the connection between pump and hose / gun  


check and let me  know


cheers  paul