wsm L3301 - Bottom Bypass System

ENGINE
L3301, L3901, L4701, WSM
1-M5
[2] BOTTOM BYPASS SYSTEM
In addition to improving the cooling performance of
the radiator by using a bottom bypass system, the
mechanism uses a 3-stage thermostat valve that
reduces thermal shock considerably compared to
previous radiators.
When the coolant inside the engine is cool, the
thermostat (4) stays closed and coolant circulates inside
the engine via the bypass pipe.
When the temperature of the coolant exceeds the
opening temperature of the thermostat (4), the
thermostat opens in three stages, sending the now hot
coolant to the radiator. Further, when the thermostat is
fully open, it is structured so the hot coolant does not flow
into the engine via the bypass circuit, thus increasing the
cooling performance of the system.
9Y1211012ENM0006US0
(1) Coolant Temperature
(2) Time
(3) Overshoot
(4) Thermostat
(A) Bypass Opened
(B) Bypass Closed
KiSC issued 09, 2016 A