| 1. |
Place the mast horizontally on a pair of saw horses or similar supports. Secure the base tube to the supports to insure that the mast does not roll off. To disassemble the mast, start with the top section and work toward the base section. |
| 2. |
To remove the top mast section, pull firmly on the yoke assembly of the top collar while pulling the top section out. Pull the top section out several inches away from the collar. Remove the set screw from the end of each latch pin lug (ears on each side of the collar). Refer to the illustration below. Slide out the latch pin spring from the end of each lug. Using a hammer and a punch, drive out the roll pin on each lug just far enough to remove the yoke assembly. Slide the latch pin out of the latch pin lug using a small screwdriver inserted into the slot located on the underside of each lug. Remove the collar bolts and slide the collar over the end of the mast section. Slide the top mast section out. Be careful not to drop it as it comes out. |
| 3. |
Remove the orifice bolt, lockwasher, back-up washer, expander and seal from the bottom of the mast section. Thoroughly clean and inspect all parts. The mast section should be cleaned inside and outside with a solvent such as lacquer thinner. Do not use anything that might scratch the honed inside surface of the mast section. Repeat this procedure for each subsequent mast section. |
| 4. |
Refer to service sheets #'s 422 and 423 for replacement of bumpers, collar Delrin and wear rings. |
| 5. |
Reassemble the orifice bolt, lockwasher, back-up washer, new expander and new seal on the bottom of the mast section. Refer to the illustration. As the orifice bolt is being tightened, center the seal on the butt plate. Torque the orifice bolt to 16 lbs-ft. Repeat this procedure for each mast section. |
| 6. |
Before reassembling the mast, lightly oil the lip of the seal and the inside honed surface of each mast section with TMD Mast Lubricant or lightweight machine oil such as SAE 10. When reassembling the mast, start with the base section and work toward the top section. |
| 7. |
Secure the base section of the mast horizontally on the saw horses. Hold the next mast section so that the top end of the section is at a lower elevation than the seal end. Next, rest the lip of the seal on the inside of the receiving section. Slowly raise the lower end of the mast section to horizontal while carefully pressing the lip of the seal into the receiving section. Use your thumbs and forefingers on both sides of the seal to simultaneously press both sides of the seal in an upward motion. Work this way until your fingers meet at the top. Make sure that the seal is in correctly. If not, the mast will eventually leak air. If the seal has not been inserted into the receiving tube correctly, remove the mast section and try again. Once the seal is inserted, guide the wear ring into position within its groove, and slide in the mast section. Be careful not to damage the seal as it slides past the collar bolt holes which are located near the insertion end of the receiving section. |
| 8. |
Slide the section in leaving several inches protruding. Rotate the section so that the match mark "O" stamped on one of the keys at the end of the section is in line with the "O" stamped on the end of the base section. |
| 9. |
Replace the collar on the mast section. Line up the match mark "O" on the collar with the "O" on the mast section. The "O" will be stamped on the collar just above one of the latch pin ears. Make certain that all the bolt holes in the collar align exactly with the holes in the mast section. Install and hand-tighten the collar bolts and lockwashers. Torque the collar bolts to 80 lbs-in maximum. |
| 10. |
Replace the latch pins with the flats on the ends perpendicular to the key on the mast section. Replace the yoke assembly. Make sure that the hole in the lever lines up with the hole in the latch ear. Drive in the roll pin while holding it in place with a punch. Make sure that the lever does not get jammed. Install the latch pin spring and set screw. Turn the set screw all the way in until it stops. Then, back out the screw approximately 1/4 to 1/2 turn. Repeat this procedure for the other latch ear. Check the yoke assembly for smooth operation. It may be necessary to readjust the set screw as much as one full turn. If the set screw is too tight, it may not allow the latch pin to retract fully when the yoke assembly is pulled. If the set screw is too loose, spring tension may not adequately load the latch pin. |
| 11. |
While pulling the yoke assembly, slide the mast section through the collar several times. Check for smooth operation. Observe the flat surface on the keys of the mast section for wear marks. If wear marks exist, the latch pin is causing friction and the set screw must be loosened. |
| 12. |
Repeat steps 6 through 11 for each subsequent mast section. |
