Vacuum Pump 4310-203-3057, Replacement of Springs, Vanes, or Pump Release

TM 9-6685-202-14

(4) Before replacing a seal assembly, apply a

g. Vacuum Pump 4310-203-3057, Replacement of

thin film of oil to shaft (10). Also, apply a thin film of oil

Springs, Vanes, or Pump Release. If the pump fails to

to the inner surface of shaft seal assembly (9). Exercise

function, the trouble usually can be attributed to a

care that inner surface of carbon seal ring (8) is not

broken spring, sticking vanes, or worn valve release.

damaged. Push seal back so that it contacts end plate

of shaft seal assembly (9). Force spring and retainer

(1) To inspect spring and vanes, remove four

washer over groove in shaft, and replace retaining ring

machine screws, (2) and top plate of cover assembly

(12).

(1). A broken spring will prevent vanes from riding

(5) Replace pulley (11) on shaft and install

snugly against rotor during cycle of operation, thus

belt on pulley. Adjust belt tension by moving motor on

causing inefficiency of operation.

base.

(2) To remove vanes (33 and 36) for

inspection, release spring (38) and remove spring lever

i. Vacuum Pump 4310-203-3057, Disassembly

arms (37) and stripper bolts (18). Turn pump shaft

Procedure. Perform the following steps to disassemble

several revolutions by hand and note how much of the

the vacuum pump for utilization of authorized

vane extends beyond the pump housing. In removing a

replacement parts:

vane, grasp only that portion which extends beyond the

pump housing with sharp nosed pliers. Use extreme

(1) To replace exhaust valve retainer and ball

care to be sure that any portion of the vane which fits

valve, remove pump assembly from pump platform.

into the vane slot is not scored or nicked in any way.

(2) Drain oil from case.

Remove one vane at a time, and under no

(3) Remove six machine bolts (5).

circumstances allow the vanes to become interchanged

(4) Remove pump mechanism from pump

or reversed in position. Polish vanes slightly with the

case (16).

finest grade of polish paper if they appear to be

(5) Remove valve retainer plate (20) and

corroded. No metal should be removed during polishing

valve balls (32) from exhaust ring (27).

process.

(6) To replace end plate (28) or rotor (30),

(3) Replace vanes (33 and 36) in their

remove pulley (11) and shaft seal assembly (9) from

original vane slots. Make certain that they have not

shaft (10).

been interchanged and are in their original position.

(7) Remove vane spring (38) and vanes (33

Install spring lever arms (37). Tighten stripper bolts

and 36).

(18). Bring lever arms into contact with vanes. Install

vane spring (38).

(8) Remove retaining ring (12) from exhaust

end of shaft.

(4) Rotate shaft pulley clockwise several

revolutions.

(9) Remove machine bolts (29).

(5) Observe that the vanes move freely and

(10) Remove machine bolts (26) and lift end

easily in. the vane slots and remain in contact with rotor

plate (28) from shaft. Pins should remain in exhaust

(30).

ring assembly.

(6) Check that top cover gasket (3) is in good

(11) Remove rotor (30) from shaft. Observe

condition; replace if necessary. Fasten cover assembly

and note which face of rotor is in contact with end plate

(1) and gasket to pump case assembly with four round

(28).

head screws (2).

(12) Remove shaft key (21) from shaft.

(13) To remove side plate (19) and rotor,

NOTE

remove four machine bolts (22) which secure side plate

The key numbers shown below in

to inlet tank.

parenthesis refer to figure, 4-9,

(14) Remove four machine bolts (24) which

except when otherwise indicated.

secure side plate to intake ring (25).

(15) Lift side plate off pins (23) and shaft. Pins

h. Vacuum Pump 4310-203-3057, Replacing Shaft

should remain in intake ring.

Seals. To replace shaft seal assembly (9) proceed as

(16) Remove rotor (30) from shaft. Observe

follows:

and note which face of rotor is in contact with side plate

(19).

(1) Remove belt and pulley (11) from pump.

(17) Remove shaft key (21) from shaft.

(2) Depress retaining ring (13) and remove

(18) With keys removed, shaft (10) can be

retaining ring (12).

withdrawn from either end.

(3) Remove shaft seal assembly (9).

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