2
Description of components
COOLING SYSTEM XE ENGINE
3-1
3. DESCRIPTION OF COMPONENTS
3.1 DESCRIPTION OF COOLING SYSTEM PRESSURE CAP
The pressure cap on the header tank is attached
to the header tank via a screw thread. To fill the
cooling system, remove this pressure cap or the
filler cap at the front of the header tank.
The pressure cap has two valves. Normally, both
valves are closed.
Overpressure in the cooling system
If the pressure (P1) in the cooling system rises
to 0.7 bar, however, the overpressure valve
opens.
The overpressure in the cooling system makes it
possible to allow a higher temperature in the
cooling system, without the coolant boiling.
Underpressure in the cooling system
If the pressure (P1) in the cooling system drops
to approximately 0.1 bar below the outside air
pressure (P2), the underpressure valve opens.
M200445
P1
P2
6
ǹ 0008