Figure 2.17. Reverser.
with soapy water. If bubbles form, the lower seat must be reground. To test the upper valve seat, press
down the button on the cover of the magnet valve housing. This has the same effect as though the
magnet coil were energized. While holding the button down, again cover the air ports with soapy water.
If bubbles appear, the upper seat must be reground. If bubbles do not appear while making the above
test, both seats fit properly.
b. Grinding valve seats. If the upper seat must be ground, coat the end of the valve stem with
grinding compound. Replace the stem in the valve housing, insert screwdriver in the slot of the
adjusting screw on the valve stem, and move it back and forth. To grind the lower seat, insert the needle
valve after coating it with