Function Of Radiator Cap; Specification Of Radiator Cap; Cooling Fan; Outline Of Cooling Fan - Kubota D1803-CR-E4 Workshop Manual

4. ENGINE

7.8.3 Function of radiator cap

(1) When at specified pressure inside radiator
The pressure valve and vacuum valve are fully seated
on their respective seats and maintain air-tightness.
Thus coolant is pressurized based on thermal
expansion of coolant water vapor raising the boiling
point temperature, preventing generation of bubbles,
and exhibiting full cooling effect.
(2) When the pressure in the radiator exceeds
specified pressure the pressure valve opens and
releases water vapor
maintaining a constant pressure inside the radiator
The pressure valve opens and releases water vapor to
the reserve tank maintaining a constant pressure inside
the radiator.
(3) When pressure inside radiator is below
atmospheric pressure
When the pressure in the radiator is below atmospheric
pressure, the vacuum valve opens suctioning coolant
from the reserve tank and preventing deformation of
the radiator.

7.8.4 Specification of radiator cap

Pressure valve open pressure
4-64
to the reserve tank
88 kPa
2
0.90 kgf/cm
13 psi
D1803-CR-E4,D1803-CR-TE4,D1803-CR-TIE4,V2403-CR-E4,V2403-CR-TE4,V2403-CR-TE4BG,V2403-CR-TIE4

7.9 Cooling fan

7.9.1 Outline of cooling fan

The cooling fan draws in outdoor air or allows air to
pass causing air to pass through the radiator.

7.9.2 Structure of cooling fan

Cooling fans are classified as suction type or blower
type depending on the direction the blades face.
(A) Suction type

7.9.3 Function of cooling fan

The cooling fan is rotated via the fan belt and fan
pulley.
The cooling fan causes outdoor air to pass through the
radiator core for cooling.
Cooling performance changes depending on the
number of blades, angle of the blades, outer diameter,
and rotation speed.

7.9.4 Specification of cooling fan

(Reference values)
Number of blades
Outer diameter
MECHANISM
7. Cooling system
(B) Blower type
7
380 mm
15.0 in.
KiSC issued 12, 2018 A