Centrifugal Pump Overhaul - TM-5-4320-234-340091

TM 5-4320-234-34

b. Use a hoist or other lifting device to support the

WARNING

weight of the pump body (5). Remove the capscrews

(6, fig. 2-1), nuts (4), and lockwashers (5), that secure

Clean all parts in a well-ventilated area.

the feet of the pump body to the chassis frame.

Avoid inhalation of solvent fumes and

c. Remove the nuts (3, fig. 5-1) and lockwashers (4)

prolonged exposure of skin to cleaning

that secure the pump body (5) to the bearing housing;

solvent. Wash exposed skin thoroughly.

slide the pump body straight out to disengage it from the

Dry cleaning solvent (Fed. Spec. P-D-680)

remainder of the pump which is secured to the engine.

used to clean parts is potentially dangerous

d. Remove the capscrews (12), and lockwashers (13),

to personnel and property. Do not use near

that secure the assembled volute (18) and wear plate

open flame or excessive heat. Flash point of

(17) to the seal plate (29); remove the assembled parts.

solvent is 100 F. to 138 F. (38 C. to 59 C.).

e. Remove the cone nut (19) that secures the impeller

(20) to the impeller shaft. Use a puller to pull the

(2) Clean all parts with cleaning solvent (Fed.

impeller from the shaft and remove the key (21).

Spec. P-D-680) and wipe dry.

Temporarily install a plain hexagonal nut on the impeller

(3) Inspect the pump body for cracks, loose

shaft to protect the threads while pulling the impeller.

or damaged studs, and for damaged threads. Clean up

Remove the shims (22 and 23), seal spring (24), and

damaged threads with a thread die Replace any

seal rotating member (25) from the shaft.

damaged studs. Replace the housing if damaged

f. Remove the nuts (27) and lockwashers (28) that

beyond repair.

secure the seal plate (29) to the bearing housing;

(4) Inspect the wear plate for wear, scoring,

remove the seal plate with the assembled seal

and distortion. If any damage is evident, replace the

stationary member (26). Remove the seal stationary

wear plate.

member from the seal plate.

(5) Inspect the volute for cracks, distortion,

internal scoring, and wear; replace if damaged.

NOTE

(6) Inspect the impeller for cracked, chipped,

The seal members are not replaceable

worn or broken vanes, damaged or distorted bore or

individually. When replacing the seal, be

keyway, and other damage; replace a defective

sure to replace all parts that are provided in

impeller.

the seal kit.

c. Reassembly. Reassemble the pump by reversing

the disassembly sequence. Refer to figure 5-1. Note

g. Install the seal stationary member (26) into the seal

the following:

plate (29); install the seal plate on the bearing housing

(1) Press the seal stationary member (26)

with nuts (27) and lockwashers (28).

into seal plate (29) before installing the plate. Lubricate

h. Lubricate the inside diameter of the seal rotating

the impeller shaft lightly with oil and slide the seal

member (25). Install the rotating member onto the

rotating member (25) and spring into place on the shaft.

shaft, and install the seal spring (24). Take care to

(2) If the same impeller (20) and wear plate

prevent damage to the interior of the seal member

(17) are reassembled and no clearance change is

during assembly, or premature failure will result. Also

indicated, use shims (22 and 23) of the same thickness

use extreme care to prevent damage to the contact

as those removed. If a new impeller and/or wear plate

faces, both the stationary and rotating seal members.

is installed, determine the shim thickness required to

i. When installing the impeller (20), be sure you install

obtain a clearance of 0.010 to 0.020 inch (0.025 to

shims (22 and 23) of the same thickness as those

0.050 cm) between the impeller and wear plate as

removed.

follows:

j. Reassemble the remainder of the pump by reversing

(a) Install impeller (20) on shaft without

the disassembly procedure.

When installing the

shims. Be sure that impeller is seated firmly against the

impeller nut (19) onto the impeller shaft, tighten the nut

shaft shoulder.

to 95 to 110 foot-pounds (13,138 to 15.213 kgm) torque.

(b) Install volute (18) with wear plate (17)

Block the impeller with a block of wood to prevent its

assembled, and secure with screws (12) and

rotation when you install the nut (19).

lockwashers (13).

5-3. Centrifugal Pump Overhaul

opening of the volute and measure from the face of the

a. Disassembly. Disassemble the pump following the

impeller (20) to the face of the wear plate (17).

sequence of index numbers in figure 5-1.

(d) Select shims (22 and 23) to equal the

b. Cleaning and Inspection.

dimension obtained less 0.010 to 0.020 inch (0.025 to

(1) Discard and replace all seals, gaskets,

0.050 cm) for clearance.

and packings.

5-3