z boy, if you do decide to install a vacuum canister you don't have to spend $65 for one, I use a camping propane canister. Make sure it's empty first, the safety valve is just a schrader valve like from the valve stem on a car tire, unscrew it and blow some air into the canister blow out any remaining propane gas then drill out the main valve and the safety valve hole to 5/16", slip in a couple of pieces of 5/16ths hard gas line and solder, braze, weld or even seam seal them in. If I remember right the brake booster requires less than 14lbs of vacuum to activate the diaphragm so not very much.