I have a steam way Powermatic 2100 machine that I been having problems for some time,the main problem is that when is running 3100 rpms and connect the vaccum engine start to acting up like it bogs down and then go back to normal then same thing happens also I notice on that the vaccum valve relief braker goes in/out on the blower,i replace the valve bran new and still same problem,any help please thank you