11
309407
Service
Displacement Pump Repair
WARNING
To reduce the risk of serious injury whenever you
are instructed to relieve pressure, always follow the
Pressure Relief Procedure
on page 7.
Before you start:
D
To reduce down time, be sure you have all
necessary repair parts available.
D
Repair Kit 237498 is available. If you have a repair
kit, use all the new parts for the best results. Parts
included in the kit are marked with an asterisk (*).
D
When cleaning parts, use a compatible solvent.
Inspect parts for wear or damage and replace as
necessary. Scoring or irregular surfaces on the
priming rod (8) or polished inner wall of the riser
tube (2) causes premature packing wear and
leaking. Check these parts by rubbing a finger on
the surface and by holding the parts up to the light
at a slight angle.
Use light, waterproof grease wherever grease is
mentioned.
Disassembly
1.
Follow the
Pressure Relief Procedure
on page
7.
2.
Remove nut (10) and priming plate (9) from
priming rod (8).
3.
Unscrew the foot valve housing (7) from cylinder
(2).
NOTE:
Poppet check (6) foot valve packings and
bearings (5) slide off priming rod (8) when
removing foot valve housing.
4.
Unscrew bearing (5) from foot valve (7).
5.
Remove the poppet check (6) and inspect foot
valve packings (30).
6.
Unscrew riser tube (2) from pump base. Clean the
tube and inspect it for wear by holding it up to a
light at a slight angle. If you see wavy lines or
scratches where the piston travels, replace the
tube as it will not seal well with the new piston
packings and the pump will perform poorly.
7.
Loosen the lock nut (4) and unscrew the valve
housing (14) from the connecting rod (3), unscrew
valve housing (14) from piston housing (16).
8.
Remove washers (35*), spreaders (34*), cup
packings (36*), o–ring (33*), and cup spacer (20)
from the piston housing (16).
9.
Clean and inspect all the parts.
Reassembly
1.
Reassemble the piston, using all the new parts
from the kit and any other new parts needed. Oil
the leather cup packings (36*) first. Then assemble
the parts on the piston housing (16) in this order:
backup washer (35*), spreader (34*), leather
packing (36*), cup spacer (20) with new o–ring
(33*) installed in it, another leather packing (36*),
spreader (34*), and backup washer (35*).
NOTE
: To replace the throat packings, follow the
procedure given in your separate air motor manual
(306982) before continuing with the procedure.
2.
Screw the piston assembly onto the connecting
rod (3) and adjust the ball travel as instructed in
Check Valve Adjustment
on page 12. Tighten the
locknut (4).
3.
Check the o–ring (13) in the pump base and
replace it, if necessary.
4.
Lubricate the piston packings and the inner wall at
the top of the riser tube (2). Wrap the packings
with with a guide collar made of 1/64 in. maximum
thickness shim stock or metal sheeting. Using a
turning motion, work the first leather packing into
the riser tube. Remove the guide collar and push
the riser tube up and screw it into the base. Torque
the tube to 100–150 ft.–lb. (135–204 N–m).
5.
Slide bearing (5) onto priming rod (8) with the step
side facing the bottom of the pump.
6.
Insert foot valve packings (30) into poppet check
(6) replace if necessary.
7.
Slide poppet check containing foot valve packings
onto priming rod (8) with beveled edge facing the
bottom of the pump.
8.
Slide foot valve over poppet check and screw
bearing (5) into the foot valve (7).
9.
Push foot valve up to the riser tube.
10. Inspect o–ring (11) for damage and replace if
necessary.
11. Screw foot valve (7) onto riser tube (2).
