vacuum reservoir

Since twin Weber manifolds have no Plenum, there is no place to get a steady vacuum signal. The reservoir is usually connected to all four intake runners and acts as a Plenum for vacuum. Connect the brake booster and vacuum gauge to the reservoir.

Larger ones also function as a Vacuum Reserve Canister. So when pulling a long hill you don't run out of vacuum for the brakes. Because vacuum is not made at heavy throttle it stores a little extra as a reserve.

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