The inflatable ribs of the extractor have about 3.5 to 4.5 inches of air pressure applied when inflated. They do not see full line pressure because the hose that leads to the shaft to fill the ribs is vented to atmosphere through a check valve. The system relies on air volume to properly inflate the ribs.
There is a pipe "T" in line with the check valve. We install a plug in the "T" which can be removed to allow measurement of the air pressure. When the inflation pressure is checked, the manometer should show between 3.5 and 4.5 inches (water column) when the check valve is working properly.
If higher pressure is seen, the air system should be inspected and the problem resolved. Check the muffler installed on the check valve for debris and rust which may block the exhaust.

GLL 052703