Graymills DDP .375' Pump OMI - Manual (Page 23)

23
Service
Diaphragm Repair
Tools Required
D Torque wrench
D One 7/16” (11 mm) and two 1/2” (13 mm)
socket wrenches
D Phillips screwdriver
D O-ring pick
D 13/32” EZY-OUT bearing extractor
D Rubber mallet
D Vise with soft jaws
Disassembly
NOTE: A Fluid Section Repair Kit is available. See page
27 for the correct kit. Parts included in the kit are marked
with an asterisk, for example (401*). Use all the parts in
the kit for the best results.
WARNING
To reduce the risk of serious injury whenever you are
instructed to relieve pressure, always follow the Pres-
sure Relief Procedure on page 11.
1. Relieve the pressure. Disconnect all hoses.
2. Remove the air valve from the pump (see page 16).
3. Remove the manifolds (102) and disassemble the ball
check valves as explained on page 21. Always replace
the o-rings (108) with new ones.
4. Using a 7/16” socket wrench, remove the clamp nuts
(113) and the grounding strip (112). Loosen the clamps
(111) and slip them over the housing (1). Pull the
covers (101) off the pump, then remove the clamps
from the housing. See the Detail in Fig. 16.
5. Using a 1/2” socket wrench on both outer diaphragm
plates (103), unscrew one plate from the diaphragm
shaft (23). Remove one diaphragm (401), inner dia-
phragm plate (118), and o-ring (404). Pull the opposite
diaphragm assembly and the diaphragm shaft out of the
pump housing (1). See Fig. 16. Clamp the shaft in a
vise with soft jaws and unscrew the outer plate (103),
then disassemble the remaining diaphragm assembly.
6. Inspect the diaphragm shaft (23
}) for wear or
scratches. If it is damaged, check the bearings (31
})
also. Replace parts as needed. To remove the bearings,
place a 13/32 EZY-OUT in a vise. Position the pump
housing (1) over the EZY-OUT (see Fig. 16). Turn the
housing in the direction shown by the arrows to
remove the bearing.
7. Hook the shaft seals (30
}) with an o-ring pick and pull
them out of the housing (1).
8. Clean all parts and inspect for wear or damage.
Replace parts as needed.