Sorry john just the standard vac and the hd vac from ashbys thanks paul
did u fit yourself ?
I would go through the whole vac system from bottom up and check that the motors are properly sealed on their manifolds and that the flex tube connecting the lower and upper motor is not loose or improperly fitted .
Not sure what else it could be ... check that u didnt get two SD motors by mistake , i think ashbys have them marked sd or hd but an amp meter would be needed to rule out a mix up .
I say its likely to be something like the loose connecting tube though .