Pneumatic Circuit System Problems Repair and Troubleshooting
5 - 32 046-006272-00 A7â„¢ Service Manual
FIGURE 5-20
Before using the negative pressure ball, make sure that it is not leaky. Check if the front sealing cover
is tightened. Then flatten the negative pressure ball to remove the gas inside. Install the gas outlet
plug properly. Block the front gas inlet with your finger then release the ball. Ball should not visibly
inflate for at least 30 seconds. If it does, replace the ball.
5.3.2 Gas Supplies and Drive Gas
The following table lists gas supplies and drive gas related failures.
Failure description Possible cause Recommended action
Leak
The gas supply tube is
damaged or the seal at the
connection is damaged.
Replace the gas supply tube or the seal at the
connection.
The quick plug-in
connector leaks.
Replace the quick plug-in connector or PU tube
(when the PU tube is not damaged, if the tube is
long enough, cut off a small segment of the tube
where the quick plug-in connector is met, and
then insert the tube into position).
The pipeline gas supply
inlet assembly leaks.
Check if the check valve of the pipeline gas
supplies inlet assembly leaks in the reverse
direction. Replace it if necessary. Check and
replace the damaged seal of the pipeline gas
supplies inlet assembly. If the problem persists,
replace the pipeline gas supplies inlet assembly.
The drive gas pipeline
leaks.
Check and repair the expiratory valve assembly as
per the procedures described in ‘‘Leak Test of Low-
pressure Pneumatic Circuit System’’ on page 5-57,
Pipeline pressure gauge
shows inaccurate
readings or no readings.
The pipeline pressure
gauge is damaged.
Replace the pipeline pressure gauge.