819.0254
19
Service
4.
Loosen but do not remove the diaphragm shaft bolts
(21), using a 15 mm socket wrench on both bolts.
5.
Unscrew one bolt from the diaphragm shaft (24) and
remove the o-ring (25), fluid side diaphragm plate
(20), diaphragm (29), and air side diaphragm plate
(20). See Fig. 12.
6.
Pull the other diaphragm assembly and the
diaphragm shaft (24) out of the center housing (5).
Remove the bolt (21) from the shaft and disassemble
the remaining diaphragm assembly.
7.
Inspect the diaphragm shaft (24) for wear or
scratches. If it is damaged, inspect the bearings (23)
in place. If the bearings are damaged, refer to page
.
8.
Reach into the center housing (5) with an o-ring pick
and hook the u-cup packings (22), then pull them out
of the housing. This can be done with the bearings
(23) in place.
9.
Clean all parts and inspect for wear or damage.
Replace parts as needed.
Reassembly
1.
Install the shaft u-cup packings (22*) so the lips face
out of the housing (5). Lubricate the packings. See
Fig. 12.
2.
Install the diaphragm assembly on one end of the
shaft (24) as follows:
a.
Install the o-ring (25*) on the shaft bolt (21).
b.
Install the fluid side diaphragm plate (20) on the
bolt so the rounded side faces the diaphragm
(29).
c.
Install the diaphragm (29*) on the bolt. Make
certain the side marked AIR SIDE faces the
center housing (5).
d.
Install the air side diaphragm plate (20) so the
rounded side faces the diaphragm (29).
e.
Apply medium-strength (blue) Loctite or
equivalent to the bolt (21) threads. Screw the bolt
(21) into the shaft (24) hand tight.
3.
Grease the length and ends of the diaphragm shaft
(24), and slide it through the housing (5).
4.
Assemble the other diaphragm assembly to the shaft
as explained in step 2.
5.
Hold one shaft bolt (21) with a wrench and torque the
other bolt to 20 to 25 ft-lb (27 to 34 N•m) at 100 rpm
maximum.
6.
Align the fluid covers (2) and the center housing (5) so
the arrows (A) on the covers face the same direction
as the air valve (B). Apply medium-strength (blue)
Loctite or equivalent to the threads of the screws (6),
and secure the covers with the screws (6) hand tight.
See Fig. 11. Using a 10 mm socket wrench, torque
the screws oppositely and evenly to 120 to 150 in-lb
(14 to 17 N•m). See Torque Sequence on page 25.
7.
Reassemble the ball check valves and manifolds as
explained on page
