everyone has their own cure to fix this problem. mine is a very low $$ cure. i sandwiched a 1/4"copper flare cap between the flare fitting on the head & the flexi hose connection. i drilled a hole in these caps to 7/64" & my low press while hot @ idle has gone. these caps are used in the refrigeration industry & cost me 10 cents. you can try a smaller hole if you desire as it doesn't cost anything to enlarge them.