Changed two boost solonoids not made a difference, would you recommend hoses ,e g r cooler leaks internally ,would this course lack of boost ?Yes. Heat does get to the rubber and causes it to harden. Vibration and movement can cause it to loosen, and this is one of the reasons why we sometimes have vacuum leaks.
Over here, a retail parts supplier "Supercheap Auto" sells 3 metres of 3mm internal diameter hose in a packet for about $20. This is perfect for the task of replacing ALL of the vac hoses for a D40 YD25 engine.