Hitachi FD2 1590 important safety instructions Reassembly

Service

4.Loosen but do not remove the diaphragm shaft bolts (107), using a 15 mm socket wrench on both bolts. See FIG. 11.

5.Unscrew one bolt from the diaphragm shaft (24) and remove the o-ring (108), fluid side diaphragm plate (105), diaphragm (403), backer (401) used only on PTFE models, and air side diaphragm plate (104).

See FIG. 11.

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 24.

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 FIG. 11.

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).

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.

c.Install the diaphragm (403*). Make certain the side marked AIR SIDE faces the center housing (1).

d.On PTFE models only, install the backer (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 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 60-70 ft-lb (81-95 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 covers with the clamps. See FIG. 10.

7.Reassemble the ball check valves and manifolds as explained on page 18.

20 311879F