I realize your posting was over 3 years ago, but... for others with
this need too.
I just talked to John Olson at GMI (763-712-8717 USA), a distributer
for Savant items (mostly used), and he had an in-house version of of the
manual he could send you via an e-mail attachment. His e-mail is
jolson from gmi-inc.com.
The biggest reason speed vacs stop working, in terms of evaporative
power, is due to dirty pump oil. Get a gauge and check the amount of
vacuum it really provides. Or, more pragmatically, just change your vac
pump oil. Yah, it's a pain. If you have something more volatile than
water to evaporate, get dry ice onto your cold trap to get the vapor
coming off of your sample into liquid phase so you can drive more vapor
off of you sample.