Purpose, Function
Ensures vacuum required for braking force to compensate for the decrease in intake manifold vacuum applied to the power brake unit caused by the retard intake valve closing.
Construction
The vacuum pump is installed to the rear housing.

For smooth vane rotation, a single-vane type vacuum pump has been adopted which is equipped with an engine oil lubrication passage.

Operation
Because the vacuum pump is directly engaged with the exhaust camshaft, the vane in the vacuum pump rotates together with the exhaust camshaft, and the vacuum chamber is expanded and vacuum is generated.

Vacuum generation mechanism

Vacuum Pump Removal/InstallationEngine SST
1: Mazda SST number
2: Global SST number
Example
1:49 UN20 5072
2:205–072
Holder
1:–
2:AKS042808
Adapter
1: 49 UN20 5072
2: 205–072
Holder
1: 49 B011 105
2: –
...
R 3 5 Brake [Fw6 A EL, Fw6 Ax EL]
Purpose/Function
The R-3-5 brake operates in 3GR, 5GR and in reverse to lock the reduction
internal gear against rotation.
Construction
The R-3-5 brake consists of the following parts shown in the figure.
The driven plate of the R-3-5 brake does not rotate be ...
Heater Core
Purpose
The heater core heats passing air.
Function
A portion of the engine coolant is taken into the heater core to heat the
air passing through the heater core.
Construction
The heater core consists of a tube which passes engine coolant, and the heat
ra ...