Hello, just joined and need some advice

[ande]

Hi, i think this is the right section, i have a 1.9d ac 306 meridian estate, i think its dw8 although that might be the gearbox, anyway, my pulley was making a racket last year so i replaced the pulley and the belt at the same time, about a week later the brand new pulley went bang and took my timing belt with it and you know what that means, anyway we got it fixed at an engine place and it has been fine since, but now the belt is ready to go, we heard it flapping about yesterday and its ready to snap, so it looks like i will have to replace the belt again, what i am worried about is it might have been my fault the new pulley went, i think i may have over tightened it, is there a proper way of doing it?