Manual

19
Service
4. Loosen but do not remove the diaphragm shaft bolts
(107), using a 15 mm socket wrench (1” on stainless
steel models) on both bolts.
5. Unscrew one bolt from the diaphragm shaft (24) and
remove the o-ring (108), fluid side diaphragm plate
(105), TeflonR diaphragm (403, used on TeflonR
models only), diaphragm (401), and air side diaphragm
plate (104). See Fig. 13.
6. Pull the other diaphragm assembly and the diaphragm
shaft (24) out of the center housing (1). Hold the shaft
flats with a 19 mm socket wrench, and remove the bolt
(107) from the shaft. Disassemble the remaining
diaphragm assembly.
7. Inspect the diaphragm shaft (24) for wear or scratches.
If it is damaged, inspect the bearings (19) in place. If
the bearings are damaged, refer to page 21.
8. Reach into the center housing (1) with an o-ring pick
and hook the u-cup packings (402), then pull them out
of the housing. This can be done with the bearings (19)
in place.
9. Clean all parts and inspect for wear or damage. Re-
place parts as needed.
Reassembly
1. Install the shaft u-cup packings (402*) so the lips face
out of the housing (1). Lubricate the packings. See Fig.
13.
2. Install the diaphragm assembly on one end of the shaft
(24) as follows:
a. Install the o-ring (108*) on the shaft bolt (107).
b. Install the fluid side diaphragm plate (105) on the
bolt so the rounded side faces the diaphragm
(401).
c. On TeflonR models only, install the TeflonR
diaphragm (403*). Make certain the side marked
AIR SIDE faces the center housing (1).
d. Install the diaphragm (401*) on the bolt. Make
certain the side marked AIR SIDE faces the center
housing (1).
e. Install the air side diaphragm plate (104) so the
rounded side faces the diaphragm (401). This plate
is used on all models, and is stamped with its part
number.
f. Apply medium-strength (blue) LoctiteR or equiv-
alent to the bolt (107) threads. Screw the bolt into
the shaft (24) hand tight.
3. Grease the length and ends of the diaphragm shaft (24),
and slide it through the housing (1).
4. Assemble the other diaphragm assembly to the shaft as
explained in step 2.
5. Hold one shaft bolt (107) with a wrench and torque the
other bolt to 20–25 ft-lb (27–34 N.m) at 100 rpm
maximum.
6. Align the fluid covers (101) and the center housing (1)
so the arrows (A) on the covers face the same direction
as the air valve (B). Apply medium-strength (blue)
LoctiteR or equivalent to the threads of the screws
(106). Secure the covers with the screws handtight.
See Fig. 12. Using a 10 mm socket wrench, torque the
screws oppositely and evenly to 120–150 in-lb (14–17
N.m).
7. Reassemble the ball check valves and manifolds as
explained on page 17.