Castle AT-8 OB - Manual (Page 26)

6.5 Tightening the PEM Nut
Note: This procedure requires two people to remove the arm assembly from the table.
The cylinder lever is held against the body of the cylinder with a PEM nut. If you notice that the
cylinder lever has come loose or that your clamp cylinder does not hold pressure the PEM nut
may have come loose. This nut can be tightened by first removing the cylinder and then
tightening up the nut.
1. Turn off the air and remove the airline for the cylinder with the loose lever. The line is
connected to the cylinder by a push-in fitting. Simply push the outer ring in as you pull
the airline.
2. Remove the arm from the upper bracket by removing the bolts in the bracket. This can
be done with the arm on the machine, but will require a second person to hold the
bottom bracket firmly against the table.
3. Loosen the tension screw on the side of the cylinder
channel.
4. Take out the two Wear Strip Attachment screws on each
side of the cylinder channel and pull the clamp cylinder
assembly off the arm.
5. Tighten the PEM nut at the top of the cylinder using a
5/16 socket and check the action of the lever. It should
be relatively difficult to move when it is off the arm.
6. Slide the cylinder(s) back onto arm.
7. Replace the cylinder assembly including the cylinder channel back onto the arm.
Replace the wear strip attachment screws and tighten.
8. Tighten the bracket tension screw until the desired slight resistance is achieved.
6.6 Rebuilding the Cylinder
The cylinders have several rings and gaskets that help maintain pressure within the cylinder.
Over time these seals can become worn or damaged and may need to be replaced. Refer to the
parts clamp cylinder detail and parts list in Appendix A & B for specific part identification.
Note: This procedure requires two people.
CASTLE, INC AT‐8 OB OWNERS MANUAL V2.1 Page 26 of 32