HYDRAULIC UNITS
CONTROL VALVE
IV-53
TB53FR
TROUBLESHOOTING
The following items are a list of all the problems that
might occur individually, but in actual practice, 2 or
3 of these problems might occur simultaneously to
compound the trouble. It is therefore desirable to
proceed so that the causes can be eliminated one at a
time.
Symptom
Probable Causes
Remedy
• Replace with a new part.
• Repair or replace the spool.
• Return to the correct shape and check
for eccentric wear of the seal lip.
• Remove paint with paint thinner or re-
move it mechanically. However, at this
time, be careful not to damage the spool
surface or the seal lip.
• Eliminate the factors causing excessive
flow resistance.
Oil leaks from spool seal. • Seal is scratched or the seal lip is worn
due to long use.
• Spool’s seal sliding portion was dam-
aged by some external cause (bruise,
scratch, etc.).
• Seal bulged out and the cover was in-
stalled in a warped state.
• Paint adhered to the sliding portion of
the spool’s seal portion during painting.
• Tank circuit’s pressure became high
and exceeded the pressure level that the
seal was capable of withstanding.
• Foreign matter is biting into the spool’s
sliding surface.
• Oil film between the spool and body
disappears due to abnormally high oil
temperature.
• Lubrication is improper due to deterio-
rating oil.
• Spool is worn from long use or due to
pressure bearing on one side only.
• Spool is bent from externally applied
pressure.
• Entire valve is strained due to strain in
the installation face.
• Valve was used at a pressure or a flow
volume which was out of specification.
• Bolts used to assemble the valve were
tightened excessively.
• Oil is accumulating in the cover (the
side with a spring or a detent) opposite
the side where the spool operates.
• Overhaul and repair or replace.
• Use some method to lower the oil tem-
perature or if the relief valve is operat-
ing frequently, investigate the cause
and reduce the frequency.
• This could be alleviated by simply re-
placing the hydraulic oil, or it could
require an overhaul of the circuit.
• Check the spool’s diameter and con-
sider the necessity of replacement.
• Check the spool’s straightness and other
factors, then repair or replace.
• Loosen the installation bolts, then cut
the installation face and edge and check.
• In the case of pressure, check with a
pressure gauge. In the case of flow
volume, check by the actuator’s speed
of movement and the capacity.
• Check if the assembly bolts are tight-
ened to the specified torque. If the torque
deviates markedly from the specified
torque, tighten them again.
• The spool is leaking oil, so when the
spool moves, oil leaks from the cover.
After confirming this, replace the seal.
• Foreign matter is biting into the load
check valve seat or large scratches were
made by foreign matter biting into the
valve's seat previously.
• Disassemble and check, then overhaul
or replace.
Spool’s sliding is not
smooth.
Cylinder drops while
shifting to a lift operation.
Summary of Contents for TB53FR
Page 1: ...0 1 TB53FR...
Page 2: ...0 2 TB53FR...
Page 3: ...0 3 TB53FR...
Page 6: ...0 6 TB53FR...
Page 8: ...0 8 TB53FR...
Page 9: ...I 1 TB53FR I GENERAL...
Page 24: ...GENERAL I 16 TB53FR...
Page 25: ...I 17 TB53FR II SPECIFICATIONS II 1...
Page 53: ...II 29 TB53FR III MACHINE CONFIGURATION III 1...
Page 60: ...MACHINE CONFIGURATION DRIVE SYSTEM III 8 TB53FR...
Page 68: ...MACHINE CONFIGURATION TRAVEL SYSTEM III 16 TB53FR...
Page 74: ...MACHINE CONFIGURATION UPPER FRAME III 22 TB53FR...
Page 80: ...MACHINE CONFIGURATION CONTROL SYSTEM III 28 TB53FR...
Page 86: ...MACHINE CONFIGURATION ATTACHMENTS III 34 TB53FR...
Page 88: ...III 36 TB53FR HYDRAULIC SYSTEM MACHINE CONFIGURATION...
Page 92: ...TB53FR MACHINE CONFIGURATION ELECTRICAL SYSTEM III 40...
Page 94: ...MACHINE CONFIGURATION ELECTRICAL SYSTEM III 42 TB53FR...
Page 110: ...MACHINE CONFIGURATION INTERFERENCE PREVENTION SYSTEM III 58 TB53FR...
Page 111: ...III 59 TB53FR IV HYDRAULIC UNITS IV 1...
Page 144: ...HYDRAULIC UNITS HYDRAULIC PUMP IV 34 TB53FR...
Page 166: ...HYDRAULIC UNITS CONTROL VALVE IV 56 TB53FR...
Page 186: ...HYDRAULIC UNITS PILOT VALVE IV 76 TB53FR INSPECTION AND ADJUSTMENT IV 71 TROUBLESHOOTING IV 72...
Page 267: ...IV 157 TB53FR V TROUBLESHOOTING V 1...
Page 313: ...V 47 TB53FR VI ENGINE...
Page 314: ......
Page 315: ......
Page 316: ......
Page 317: ......
Page 318: ......
Page 319: ......
Page 320: ......
Page 321: ......
Page 322: ......
Page 323: ......
Page 324: ......
Page 325: ......
Page 326: ......
Page 327: ......
Page 328: ......
Page 329: ......
Page 330: ......
Page 331: ......
Page 332: ......
Page 333: ......
Page 334: ......
Page 335: ......
Page 336: ......
Page 337: ......
Page 338: ......
Page 339: ......
Page 340: ......
Page 341: ......
Page 342: ......
Page 343: ......
Page 344: ......
Page 345: ......
Page 346: ......
Page 347: ......
Page 348: ......
Page 349: ......
Page 350: ......
Page 351: ......
Page 352: ......
Page 353: ......
Page 354: ......
Page 355: ......
Page 356: ......
Page 357: ......
Page 358: ......
Page 359: ......
Page 360: ......
Page 361: ......
Page 362: ......
Page 363: ......
Page 364: ......
Page 365: ......
Page 366: ......
Page 367: ......
Page 368: ......
Page 369: ......
Page 370: ......
Page 371: ......
Page 372: ......
Page 373: ......
Page 374: ......
Page 375: ......
Page 376: ......
Page 377: ......
Page 378: ......
Page 379: ......
Page 380: ......
Page 381: ......
Page 382: ......
Page 383: ......
Page 384: ......
Page 385: ......
Page 386: ......
Page 387: ......
Page 388: ......
Page 389: ......
Page 390: ......
Page 391: ......
Page 392: ......
Page 393: ......
Page 394: ......
Page 395: ......
Page 396: ......
Page 397: ......
Page 398: ......
Page 399: ......
Page 400: ......
Page 401: ......
Page 402: ......
Page 403: ......
Page 404: ......
Page 405: ......
Page 406: ......
Page 407: ......
Page 408: ......
Page 409: ......
Page 410: ......
Page 411: ......
Page 412: ......
Page 413: ......
Page 414: ......
Page 415: ......
Page 416: ......
Page 417: ......
Page 418: ......
Page 419: ......
Page 420: ......
Page 421: ......
Page 422: ......
Page 423: ......
Page 424: ......
Page 425: ......
Page 426: ......
Page 427: ......
Page 428: ......
Page 429: ......
Page 430: ......
Page 431: ......
Page 432: ......
Page 433: ......
Page 434: ......
Page 435: ......
Page 436: ......
Page 437: ......
Page 438: ......
Page 439: ......
Page 440: ......
Page 441: ......
Page 442: ......
Page 443: ......
Page 444: ......
Page 445: ......
Page 446: ......
Page 447: ......