Kubota M108S, Workshop Manual

Page: 486 / 523

10-S11
M108S, WSM CABIN
(3) Vacuum Pump Adaptor
Objective of the Vacuum Pump Adaptor
1. After vacuum has been created in the air conditioning cycle,
when the vacuum pump is stopped, since there is vacuum in
hoses within the gauge manifold, the vacuum pump oil flows back
into the charging hose. If the refrigerant is refilled with the system
still in this state, the vacuum pump oil left in the charging hose
enters the air conditioner cycle together with the refrigerant.
Vacuum pump adaptor with a solenoid valve is used to prevent
this back-flow of oil from the vacuum pump. The role of the
solenoid valve is that when the current passes through the
solenoid valve, the valve closes to keep out the outside air and
allow the vacuum to build up, but when the current stops, the
valve opens to allow in air and end the vacuum.
2. Attaching this adaptor to the R12 vacuum pump currently being
used allows the pump to be used with both R134a and R12.
W1014539
(4) Electric Gas Leak Tester
The current R12 gas leak tester has poor sensitivity for R134a
and cannot be used. Therefore, a new electric gas leak tester with
greater sensitivity has been designed and can be used with both
R134a and R12.
(Reference)
Leak tester with halide torch
• Since the reaction with chlorine within the refrigerant is used to
detect gas leaks, R134a, which contains no chlorine, cannot be
detected.
W1014905
(1) Vacuum Pump Adaptor
(2) Vacuum Pump
(3) Magnetic Valve
(4) Blind Cap (5) Air
(6) For R134a
(7) For R12
(1) Electric Gas Leak Tester
KiSC issued 06, 2007 A