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Hydraulic System Pressure Test

NOTE: Hydraulic system pressure test information for Turbo Diesel models is not available from manufacturer.
  1. Remove pump reservoir cover and draw off fluid with syringe. Remove high pressure hose from pump. Connect High Pressure Tester (124-589-06-21-00 ) and Adapter Kit (201-589-02-63-00 for 190E and 300 Series (gasoline), 124-589-19-63-00 for 420SEL and 560 Series) inline between pump and high pressure hose. Fill reservoir to cast-in mark.
  2. With engine idling and tester valve open, measure circulating pressure. DO NOT turn steering wheel during measurement. Pressure should NOT be greater than 73 psi (5.13 kg/cm2 ).
  3. Raise engine speed to 1000 RPM. Close tester valve for maximum of 5 seconds to measure maximum pressure. See POWER STEERING PUMP MAXIMUM PRESSURE  table. If pump maximum pressure is not as specified, rebuild or replace pump assembly.
POWER STEERING PUMP MAXIMUM PRESSURE

Model psi (kg/cm2 )
190E (1)
300 Series (Gasoline) 1590-1600 (112-113)
300D Turbo Diesel & 350 Series (1)
420SEL & 560 Series 1185-1195 (83-84)
(1) Information is not available from manufacturer.