Cant find anything on the net its very old. Mabye need to get a new one

 

Have you checked hoses/inlets/nozzles for any blockages? I'm no expert but think it's where I'd start....BTW Mine pulses the odd time but I think it's because the outside tap is coming off the washing machine cold feed,as it only happens when the washer's on.
Mike

 

Yea mine would pulse sometimes. Just building pressure i think. When it went it was pluged in. I wasnt using it and it started to gradually get louder as the machine went to work harder and harder. Its on all the time as if ive got the trigger pulled. Yes i will take a look at that thanks!!!