Bosch Pressure Washer

[DerbyBorn]

Aquatak 110.

Looking at a neighbours machine fore her. Symtoms - Not turning off when trigger released and water pisses out of the lower part of the maching.

Removed covers and taken the piston out. It seems that the piston that operates the switch has a small O Ring inside (is it some sort of safety valve) which has partly blown out.

I am guessing the switch is knackered and the over pressure protection has kicked in.

Any thoughts?

[David Lang]

Probably about right. The piston moves when the pressure rises (when the gun is shut) and triggers a microswitch.

There may well be a safety valve which is operating. Replace the O ring.