After changing the diaphragm, if it is necessary to
purge air from the rest of the hydraulic system, clamp a piece
of sheet metal over the diaphragm so that it cannot distend.
Remove the cap from the bleeder valve adjacent to the gage or
transducer. By means of a special device for forcing hydraulic
fluid into the system or by manually operating the hydraulic
system, force the hydraulic fluid through the system until it
emerges from the bleeder valve with an even flow and no
evidence of free air bubbles are observed. Replace the cap on
the bleeder valve before the fluid stops flowing. Remove sheet
metal from clamping device and check diaphragm height,
adjusting if necessary.