Troubleshooting guide



Air Motor and Throat Service
Before you start:
1. Be sure you have all necessary parts on hand. Air
Motor Repair Kit 206–728 includes repair parts
for the motor . Use all the parts in the kit for the
best results. Parts included in the kit are marked
with one asterisk, for example (28*), in the t ext
and drawings. See the Parts List for your pump
model number .
2.
Displacement Pump Repair Kit 237–498 in -
cludes repair parts for the pump throat and piston.
Use all the parts in the kit for the best results.
Parts included in the kit are marked with a symbol,
for example (6  ), in the text and drawings. See the
Parts List
for your pump model number .
3.
Three accessory tools should be used. Padded
Pliers, 207–579, are used to grip the trip rod with -
out damaging its surface. Gauge, 171–818 , is
used to ensure the proper clearance between the
poppets and seat of the transfer valve. Guide Col -
lar T ool, 168–085, is used to install the piston in
the displacement pump cylinder during pump serv -
icing.
Disassembly
1. Flush the pump. Follow the Pressure Relief Pro -
cedure on page 9 before proceeding.
2. Disconnect the hoses, remove the pump from its
mounting, and clamp the air motor base in a vise.
3. Use a strap wrench on the displacement cylinder
(16) to screw it out of the air motor base (52).
4. Pull the connecting rod (15) down as far as it will
go.
5.
Use a hammer and punch to remove the roll pin
(4) from the piston rod (44), and then screw the
connecting rod (15) out of the piston rod. See
Fig. 4.
CAUTION
Do not damage the plated surface of the trip rod
(51). Damaging the surface of the trip rod can re -
sult in erratic air motor operation. Use the special
padded pliers, 207–579, to grasp the rod.
6. Manually push up on the piston rod (44) to move
the piston assembly (53) up as far as it will go. Un -
screw the cylinder cap nut (45). Pull the nut up.
Grip the trip rod (51) with padded pliers 207–579
and screw the nut of f the rod. See Fig. 4.
7. Remove the six screws (22) holding the cylinder
(31) to the base (52). Carefully pull the cylinder
straight up of f the piston (53).
CAUTION
T o avoid damaging the cylinder wall, lift the cylinder
straight up of f of the piston. Never tilt the cylinder
as it is being removed.
Fig. 4
52
16
15
4
44
51
53
45
31
04117