Sealey vs4021 vacuum tester brake bleeding kit sealey vs4021 multi function diagnostic tool used to test a variety of essential engine and associated functions including fuel ignition transmission and emissions kit also includes reservoir hoses and adaptors for bleeding brake and clutch systems on cars commercials and motorcycles brass bodied vacuum pump features large easy to read vacuum gauge calibrated in both inches and millimetres of mercury sealey vs4021 vacuum tester brake b