Air Motor and Throat Service
Air Motor and Throat Service
Before You Start
•Be sure you have all necessary parts on hand. Pump Repair Kit 246918 includes repair parts for the pump and air motor. Use all the parts in the kit for the best results. Parts included in the kit are marked with one asterisk, for example (17*), in the text and drawings. See Parts, page 14.
•Two accessory tools should be used: Padded Pliers, 248198, are used to grip the trip rod without damaging its surface. Gauge, 15E796, is used to ensure the proper clearance between the poppets and seat of the transfer valve.
Disassembly
1. Flush the pump, and relieve the pressure.
To reduce the risk of serious injury whenever you are instructed to relieve pressure, always follow the Pressure Relief Procedure on page 6.
2.Disconnect the ground wire from the grounding screw (28a), disconnect the hoses, remove the pump from its mounting, and clamp the air motor base in a vise horizontally by closing the vice jaws on the flange.
3.Use a strap wrench on the fluid cylinder (105) to screw it out of the air motor base (28). See Parts, page 14.
4.Pull the displacement rod (29) down as far as it will go. See FIG. 3.
5.Using wrenches on the flats of the displacement rod (29) and on the flats of the fluid piston (107), unscrew the fluid piston from the displacement rod. Remove the ball (100) from the end of the displace- ment rod, and remove the packing
6.Clamp the air motor upright in the vice by closing the vice jaws below the flange.
7.Unscrew the cylinder cap nut (39) from the top of the air motor cylinder (35).
8.Pull up on the cylinder cap nut (39) to expose the trip rod, grasp the trip rod with padded pliers (Part No. 248198), and unscrew the cylinder cap nut from the trip rod.
CAUTION
Do not damage the plated surface of the trip rod (40). Damaging the surface of the trip rod can result in erratic air motor operation. Use the special padded pliers to grasp the rod.
9.Remove the six screws (9) holding the air motor cylinder (35) to the air motor base (28), and care- fully pull the cylinder straight up off of the piston (34).
CAUTION
To avoid damaging the cylinder wall, lift the cylinder straight up off of the piston. Never tilt the cylinder while you are removing it.
10.Pull the air motor piston/displacement rod assembly (29, 34) clear of the air motor base (28) by pulling up on the air motor piston.
11.Remove the
packing (16*) from the air motor base (28). Use nee-
39
35
40
18* | 32* |
19 | 34 |
13* | 28a |
|
9
16*
flange 
29
28
05725B
FIG. 3
8 | 309868D |