Service
20
309528L
5.
Unscrew one bolt from the diaphragm shaft (24) and
remove the o-ring (108), fluid side diaphragm plate
(105), PTFE diaphragm (403, used on PTFE mod-
els only), diaphragm (401), and air side diaphragm
plate (104). See F
6.
Pull the other diaphragm assembly and the dia-
phragm shaft (24) out of the center housing (1).
Hold the shaft flats with a 19 mm open end wrench,
and remove the bolt (107) from the shaft. Disassem-
ble 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
22.
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 bear-
ings (19) in place.
9.
Clean all parts and inspect for wear or damage.
Replace 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 F
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 dia-
phragm (401).
c.
On PTFE models only, install the PTFE dia-
phragm (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) Loctite
®
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). Secure the covers with
the screws handtight. See Fig. 13. Using a 10 mm
or 13 mm socket wrench, torque the screws oppo-
sitely and evenly to 120-150 in-lb (14-17 N•m) 1040
pump models and 190-220 in-lb (22-25 N•m) on
1590 and 2150 pump models. See Torque
Sequence, pages 24-25.
7.
Reassemble the ball check valves and manifolds as
explained on page 18
The fluid side diaphragm plate (105) is stainless
steel. This plate is not stamped with its part num-
ber. Be sure to install this plate on the fluid side of
the diaphragm.
