Humboldt H-4210A Portable, Static Cone Penetrometer - Manual (Page 5)

4. Using a long screw driver, or similar tool, press the Piston (Item 6) out of the
bottom of the Head.
5. Replace the “0” ring (Item 5), being careful not to damage it.
6. Replace the Piston from the bottom of the Head, with the drilled hole facing
outward.
CAUTION: The Piston must be inserted from the BOTTOM of the Head to prevent
damage to the “0” ring and should not be pushed above the Gauge opening.
7. Reinstall the Insert in the bottom of the Head Assembly, using the bolt and nut.
NOTE: Loctite ® thread fastener is recommended to insure the Insert does not
unthread during use.
8. Using a long screw driver or similar tool, press the Piston from the top (or
Adjustment Screw end) of the Head down against the Insert, being careful not to
damage the bore.
9. Refill the Head with Automatic Transmission oil until flush with the top.
10. Drop in the brass Adjustment Screw and thread clockwise until flush with the top.
NOTE: Oil will run out during this step, preventing air from being trapped inside.
11. Screw the Outer Rod Assembly into the Head Assembly, watching the needle of
the Gauge. If the Gauge needle begins to move, back out the Adjustment Screw to
allow the excess oil to escape.
CAUTION: Failure to allow excess oil to escape will over-pressurize and damage
the Gauge.
12. Once the Outer Rod Assembly is tight, the Adjustment Screw is turned clockwise
until the needle on the Gauge begins to move. At this time, back off the Screw
until the Gauge reads zero.