Hydraulic Power Unit (2)

Hydraulic power unit comprises an electrically driven pump and a pressure switch. The pressure switch incorporates 3 electro-mechanical switches: one for pump, another, at a different pressure setting, to illuminate pressure warning light. The latter switch plus third switch inform ECU of low pressure and that ABS function should cease whilst pressure remains low. The pump also incorporates a non-return valve, a low pressure inlet filter, and a pressure relief valve to protect system.