I have an old WAP DX820 diesel fired hot water pressure washer, the burner fires ok, but it's not making pressure.

Just wondered if anyone on here knows much about them, and could give me some pointers of where to start looking.

There doesn't seem to be much info available online for WAP and i can't find a manual anywhere.

Cheers

Al.

start with the unloading valve thats the usual suspect not much you can do with them you could try n clean it out they can scale up

Cheers, is that like a bypass valve ? i'm guessing you mean it might be stuck open, so no pressure can build ?

Is it supposed to close when you press the trigger.

Al.

closed when trigger of realesed when pulled , mine does anyway . got through a few in me time i just put a new one on job sorted never had much luck cleaning them out about 1 in 20 chance

Thanks for that, just found a couple of sites which explain basic operation, with diagrams for dummys like me