Leak Diagnostic Pump
- Raise and support vehicle. Disconnect leak diagnostic pump rear hose marked "A" and fit a piece of hose and plug over the hose connection. Disconnect pump front hose marked "C" and fit Pressure Regulator (999-5646) to pump. See Fig 1.NOTE: Hang manometer vertically to ensure accurate measurement.
- Connect Manometer (999-5230) to Pressure Regulator (999-5646) and connect compressed air supply. Set pressure regulator to a maximum of 3 psi (20 kPa). See Fig 1.
- Pressurize system for 5 minutes. Close regulator valve when pressure exceeds 3.7 psi (25 kPa).
- Disconnect compressed air and monitor pressure in system for 30 minutes. Pressure must not drop below 2.5 psi (17 kPa). Feel and listen for air leakage from rear pump hose (marked "A") and from around diagnostic pump. See Fig 1. If pressure drop exceeds specification, there is an internal leak in diagnostic pump. Replace entire pump. See LEAK DIAGNOSTIC PUMP in REMOVAL & INSTALLATION - S40 & V40 article. If pressure remains as specified, pump is OK. Go to next step.
- Remove manometer, regulator and plugs from diagnostic pump. Fit diagnostic pump hoses onto pump and ensure proper seal. Use a NEW clamp for front hose.