MAINTENANCE

Maintenance must be performed on all carbon dioxide equipment on a periodic basis. These maintenance procedures are discussed in the following paragraphs.

Once Every Month

Check the level of the oil in the crankcase. See that it is within one-fourth inch of the top of the filling cup or to the upper groove in the measuring stick if the unit is so equipped. If you must add any oil, use only a good grade of SAE viscosity #30 automotive crankcase lubricating oil.

Once Every 6 Months

Lubricate the idler shaft. This shaft is equipped with a fitting of the variety that is commonly used in the automotive field. Two or three "shots" of light cup grease will be ample.

Lubricate the gear teeth with a thin coating of light cup grease.

With a small piece of wood, or preferably a small brush, apply a light coating of Vaseline to the piston rod. To do this, dip the brush in Vaseline, hold the brush against the piston rod, and manually rotate the gears until the piston rod is completely and thoroughly coated with Vaseline.

If necessary, tighten the packing at the piston stem. A special wrench is provided for this purpose. Do not tighten excessively. Because of the design of the packing, it must only fit snugly to hold tightly.

Keep the motor commutator clean and maintain a clean surface. Under normal operating conditions, the commutator will require only occasional cleaning with a dry piece of nonlinting cloth. Do not lubricate the commutator.

Every 12 Months

The oil should be drained from the crankcase and replaced with clean, fresh oil of the quality and viscosity specified.

Once Every 2 Years

The bearing housings of the electric motor should be removed and lubricated. To do this, disassemble the bearing housing. Then clean the inside of the housings, the plates or caps, and the bearings with carbon tetrachloride. Wipe off all grease and reassemble all parts except the outer caps or plates. Apply the new grease, either from a tube or by hand, over and between each ball. When you do this, do not apply more than one-half of an ounce of grease at each bearing.

Too much grease may cause excessive bearing temperature and cause the grease to leak out of the housing to the windings.

Piston Rod Packing

Piston rod packing should be replaced once every 2 years. To replace the piston rod packing, use the following steps:

1. Remove the six bolts on top of the cylinder head. Remove the cylinder head.

2. Loosen the hex nut (figure 3-2) at the bottom of the piston rod.

3. Remove the three bolts that hold the cylinder body to the crosshead guide unit.

4. Raise the cylinder body and unscrew the piston rod from the crosshead so that it clears the base.

5. The piston rod packing is now in a position to be replaced. Remove the locknut from the piston rod and then remove the piston rod packing nut.

6. When you replace the flanged-type packing, remember that the packing nut serves only to hold the packing in place. Tightening the nut excessively will not increase its efficiency; the packing nut should not be forced down tight enough to damage the packing flange.

7. After you replace the packing and packing nut, mount the cylinder body on the crosshead guide. Make certain that the locknut is replaced on the piston rod before you screw it into the crosshead.

8. Screw the piston rod into the crosshead until the top edge of the piston packing is flush with the top of the cylinder body, with the crosshead in the uppermost position (figure 3-2). To check this adjustment, rock the crank back and forth; then tighten the locknut at the bottom of the piston rod.

9. Replace the piston head and tighten all the mounting bolts.