Advice, BEFORE I BLOW UP my Sherline?

I've opened the Sherline motor, and have run wires from the two brushes
to the outside of the motor (through the top), I am now going to connect
a cap between the brushes, and each brush through a cap to ground (the
motor casing). The caps are (big chunky) 400VAC rated 0.68uf.
I'm about to step out for a bit.. and test it when I return, so....

Can anyone advice me if this setup is going to work? Should I put a
series resistor inline with any of the caps just in case they decide to
short out?
Or is this setup okay. The plan is to reduce some of the noise which is
causing so much pain (steppers doing their own spindle-dance etc)
Thanks!
Ab