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275B SER
800-00152
Oil leaks between sections.
Pinched or blown section seal.
Stud fasteners not correctly
torqued.
Mounting plate not level.
Replace seal.
Replace seals and retorque.
Loosen mounting bolts and shim
as required.
Spring - centered spools do not
return to neutral.
Broken centering spring.
Misalignment of operating linkage.
Foreign particles in system.
Replace spring.
Check linkage for mechanical
binding.
Clean valve & system.
Load will not hold.
Cylinder leaking or worn.
Port relief valve not holding.
Spool or housing scored or worn
excessively.
Check cylinder. Repair.
Remove & clean or replace.
Replace section.
Load drops when spool moved
from neutral.
Dirt or foreign particles lodged
between check valve poppet and
seat.
Scored or sticking check valve
poppet.
Disassemble, clean, &
reassemble.
Replace poppet.
No motion, slow or erratic system
operation.
Worn pump.
Defective cylinder or motor.
Low reservoir oil level.
Clogged suction strainer.
Suction line restricted.
Relief valve not properly set.
Relief valve poppet or seat scored
& sticking.
Valve spool not shifted to full
stroke.
Check flow & pressure.
Repair or replace.
Add oil to specs.
Clean or replace.
Check lines.
Check pressure setting.
Replace relief valve.
Check spool linkage travel.
TROUBLE
TROUBLE
TROUBLE
TROUBLE
TROUBLE
REMEDY
REMEDY
REMEDY
REMEDY
REMEDY
PROBABLE CAUSE
PROBABLE CAUSE
PROBABLE CAUSE
PROBABLE CAUSE
PROBABLE CAUSE
Oil leaks at either end of spool.
Correct high back-pressure
condition.
Replace seals.
Over pressurized tank core.
Worn or damaged spool seals.
A20/A35 CONTROL VALVE MAINTENANCE CONTINUED...
A20/A35 CONTROL VALVE MAINTENANCE CONTINUED...
A20/A35 CONTROL VALVE MAINTENANCE CONTINUED...
A20/A35 CONTROL VALVE MAINTENANCE CONTINUED...
A20/A35 CONTROL VALVE MAINTENANCE CONTINUED...
TROUBLESHOOTING CHART
TROUBLESHOOTING CHART
TROUBLESHOOTING CHART
TROUBLESHOOTING CHART
TROUBLESHOOTING CHART
