What’s wrong w my pressure washer trigger?

[chainsaw_louie]

Hi, 

We recently used our pressure washer (Graco 4000 psi with 8 hp Honda gas engine) and the trigger in the wand would only work once to turn on the flow while the pressure is building on low rpm but when the engine gets up to full speed and I press the trigger nothing happens.  

I looked at the manufacturer parts diagram but they don't list any individual parts for the spray gun/wand , just the complete unit.

Has anyone seen and resolved a similar issue with a pw gun trigger ?

Thanks !

[doc henderson]

It could be priming or the pump.  borrow a different wand and see if that fixes it.  If not, check the pump.  i assume the supply is adequate.

[sawguy21]

It sounds like a problem with the relief valve on the pump. What is the make of the pump?

[Southside]

I have had that happen and think the valve is stuck in the wand.  I tried penetrating spray, disassembly, and ordering a replacement.  Only the third option worked. 

[mike dee]

Hard water scale and crud can cause grief for your wand and unloader valve

[charles mann]

With the wand disconnected and the washer running, does it flow water? If so, try a new wand. If not, sounds like the pump took a crap. Our washer at work just crapped out. It used to gravity draw from our 300 gal bladder but here recently, only using our pony pump would it work. Now it has fully crapped out.