Cleaning and Installation

KEY to fig. 4-1:

ture failure. Any scratching or scoring of the seal faces

1. Gate valve

makes seal replacement mandatory. Always replace

18. Screw

2. Pipe nipple

19. Wear ring

the complete seal assembly, not individual parts.

3. Cap and chain

20. Impeller

(2) Clean all remaining parts with cleaning sol-

4. Gasket

21. O-ring seal

vent (fed. spec. P-D-680); dry thoroughly.

5. Coupling

22. Shaft seal

(3) Inspect the impeller for cracks, wear, bro-

6. Nut

23. Shim

ken vanes, chips, distortion and damaged threads.

7. Lock washer

24. Shim

Replace wear rings (19 and 28) if scored or damaged.

(4) Inspect the wear rings in the pump body

8. Cap screw

25. Shim

9. Flat washer

26. Sleeve

and in the intermediate coupling for scoring, wear,

10. Bushing

27. Screw

cracks, and other damage. If inspection indicates wear

11. Pipe plug

28. Wear ring

or damage, you must replace the wear rings.

12. Stud

29. Nut

(5) Inspect the pump body for cracks, distor-

13. Nut

tion, damaged threads, or other damage. If studs are

30. Lock washer

14. Lock washer

31. Intermediate coupling

damaged, replace them.

15. Pump body

(6) Inspect the intermediate coupling (31) for

32. Stud

16. Stud

33. Slinger

cracks, distortion, scoring, and other damaged;

replace a damaged intermediate coupling.

17. O-ring gasket

c. Reassembly and Installation.

(1) Install the wear rings (19 and 28) if you had

(1) Remove the cap screws (8), flat washer (9),

nuts (6), and lock washers (7) that secure the pump

removed them.

(2) Sparingly coat the end of the engine

body to the trailer frame. Remove the nuts (13) and

lock washers (14) that secure the pump body to the

crankshaft with light engine oil. Install the shaft sleeve

intermediate couplng (31) mounted on the engine.

(26) on the shaft and position the slinger (33) on the

Support the weight of the pump body with a hoist and

shaft.

pull straight forward to disengage the body from the

(3) Sparingly coat the O-ring and stationary

member of the shaft seal (22) with light engine oil.

pump. Remove the O-ring gasket (17).

Install the stationary seal parts in the bore of the inter-

(2) Place a wooden block against one of the

impeller blades and strike sharply on the end of the

mediate coupling (31). Install the intermediate cou-

wooden block to rotate the impeller (20) counterclock-

pling on the engine, taking care you do not dislodge the

wise to enable you to loosen it from the end of the

stationary seal members. Secure with nuts (20) and

lock washers (30).

engine crankshaft. You may find it necessary to block

the rotation of the engine flywheel to facilitate

impeller removal.

CAUTION

The mating faces of the shaft seal are

(3) When the impeller is removed, remove the

highly machined and are easily damaged

O-ring seals (21) from the impeller. Slide the rotating

seal members (part of item 22) from the shaft. Remove

by rough handling and careless installa-

tion. Take care when you install seal parts

the shims (23, 24 and 25) and shaft sleeve (26). Retain

or premature pump failure may result.

the shims as a set. You will want to reinsert the same

shim thickness at reassembly unless related parts are

(4) Coat the face of the rotating seal member

replaced,

with light engine oil. Install the rotating seal members

(4) Remove the nuts (29) and lock washers

(30) that secure the intermediate coupling (31) to the

on the shaft.

engine, Remove the intermediate coupling by pulling

(5) Install the O-ring seals (21) on the impeller

it straight away from the engine. Push the assembled

(20). Install the impeller on the engine crankshaft

without shims (23, 24) and (25). You will note that the

stationary seal member (part of item 22) and O-ring

gasket (17) from the intermediate coupling.

impeller has a right hand thread.

(6) With the impeller (20) firmly seated on the

(5) Remove the slinger (33) from the engine

shaft, measure the distance from the mounting flange

crankshaft.

of the intermediate coupling (31) to the near side of the

(6) You should not remove the studs (12 and

16) from the pump body unless they are damaged and

impeller discharge slot (dimension A, fig. 4-2). Mea-

require replacement. Removal of wear rings (19 and

sure the distance from the machined mounting surface

28) is not required unless your inspection indicates

of pump body to the slot in the inside diameter of the

that they require replacement.

pump body (dimension B). Subtract dimension B

b. Cleaning and Installation.

from dimension A. The remainder must be at least

(1) Replace the O-ring gasket (17) and (O-ring

0.125 inch. If it is not, remove the impeller and add

seals (21). You should replace the shaft seal (22) at

shims (23, 24, and 25) (fig. 4-1) to increase the differ-

ence to 0.125 inch when the impeller is reinstalled.

each overhaul to minimize the possibility of prema-

4-3