Intermediate problem solving – Hitachi 231580 User Manual

Page 15

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15

Intermediate Problem Solving

TYPE OF PROBLEM

WHAT TO CHECK

If check is OK, go to next check

WHAT TO DO

When check is not OK, refer to this column

Low output

(continued)

3. Release gun trigger. Observe resting position of

pump rod (107).

3. If pump consistently comes to rest with

rod (107) fully extended, the piston pack-

ings and/or piston valve may be worn.

Service the pump. See page 21.

4. Check electrical supply with volt meter. Meter

should read 105–125VAC.

4. Reset building circuit breaker; replace

building fuse. Repair electrical outlet or

try another outlet.

5. Check extension cord size and length; must be

at least 12 gauge wire and less than 150 ft

(45 m) long.

5. Replace with a correct, grounded exten-

sion cord.

6. Check motor brushes. See Electrical – What To

Check, item 4, on page 13.

6. See page 19.

7. Check motor start board (47) by substituting

with a good board.

CAUTION: Do not perform this check until mo-

tor armature is determined to be good. A bad

motor armature can burn out a good board.

7. Replace board. See page 23.

8. Check motor armature for shorts by using an

armature tester (growler) or perform motor test.

See page 17.

8. Replace motor. See page 22.

Drain valve leaks

1. Check drain valve for correct torque and/or

worn parts. Check for debris trapped on seat.

9. Tighten to 185 in–lb (21 N.m). Clean

valve and replace with new gasket (42a)

and sealant (42d). See page 28.

Transducer leaks

1. Slight leakage from transducer is normal.

1. Periodically remove residue from its cyl-

inder port. See page 27.

No output: motor runs and

pump strokes

1. Check paint supply.

1. Refill and reprime pump.

2. Check for clogged intake strainer.

2. Remove and clean, then reinstall.

3. Check for loose suction tube or fittings. See

page 30.

3. Tighten; use thread sealant on npt

threads of adapter (38).

4. Check to see if intake valve ball and piston ball

are seating properly. See page 21.

4. Remove intake valve and clean. Check

ball and seat for nicks; replace as need-

ed. See page 21. Strain paint before us-

ing to remove particles that could clog

pump.

5. Check for leaking around throat packing nut

which may indicate worn or damaged packings.

See page 21.

5. Replace packings. See page 21. Also

check piston valve seat for hardened

paint or nicks and replace if necessary.

Tighten packing nut/wet-cup.

6. Release gun trigger. Observe resting position of

pump rod (107).

6. If pump consistently comes to rest with

rod (107) fully extended, the piston pack-

ings and/or piston valve may be worn.

Service the pump. See page 21.

No output: motor runs but

pump does not stroke

1. Check displacement pump connecting rod pin

(17). See Fig. 18, page 21.

1. Replace pin if missing. Be sure retainer

spring (18) is fully in groove all around

connecting rod.

7. Check connecting rod assembly (15) for dam-

age. See page 24.

7. Replace connecting rod assembly. See

page 24.

8. Be sure crank in drive housing rotates; plug in

sprayer and turn on briefly to check. Turn off

and unplug sprayer. See page 24.

8. Check drive housing assembly for

damage and replace if necessary. See

page 24.

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