Parts and Service Guide
Sentry
™
Washfountain
Bradley Corporation • 215-1472 Rev. F; EN 06-915
27
2/12/07
Troubleshooting Air Valve Metering Hand Control (AST4)
....Continued
Problem: An individual operating station won't turn off and drips.
Cause:
There is debris trapped between the diaphragm and valve seat.
Solution: Remove debris between the diaphragm and valve seat.
1. Remove the three Phillips-head screws that hold the air valve together. Be careful not to lose the
armature or spring (see Page 25).
2. Remove the diaphragm. Remove any debris trapped between the diaphragm and the valve seat.
3. Rinse off the diaphragm and inspect for damage. Make sure the center orifice and the two small
side orifices are open.
4. Reassemble in reverse order, being careful not to over tightening the Phillips-head screws or you
may crack the plastic valve body. Tighten until the armature plate makes contact with the plastic
body.
Problem: An individual station will not shut off.
Cause:
Timing mechanism is clogged.
Solution: Clear the timing mechanism.
1. If the timer cover has been sprayed with water, wait at least two minutes. It will shut off and
return to normal operation once it dries off.
2. If it doesn't turn off remove the timer cover. If the valve shuts off the cover is clogged and
needs to be replaced.
3. If the valve still doesn't turn off, turn the adjusting screw counter clockwise until it can be
removed from the valve body.
4. Wipe adjusting screw thoroughly with a lint-free towel making sure that there is no water or
debris on the adjusting screw.
5. Use a pipe stem cleaner to wipe the inside of the timer body if possible.
6. Replace timer-screw and adjust valve timing.
7. Replace timer cover.