Operator
’s Manual Backhoe Series BH
- Page 61 of 91 -
Version 2.0
Problem:
Cause:
Solution:
Unable to push the
valve spool in.
Paint on valve spool; sticking
valve spool or scored valve
spool.
Clean valve spool. Binding is usually caused by an over-
tightened plug, mounting bolt, fitting in the valve body, or tie rod
bolt. If a plug or fitting in the valve body leaks, do not over-
tighten to stop the leak. It will distort body casting and cause
spools to bind. Instead, the plug and fitting should be removed
from the valve body and reconnected using a new O-ring. Do not
apply excessive pressure on mounting bolts. The rods should be
torqued to 20 ft./lbs.
Never force the spool; if binding occurs, then see the important
instruction in § 7.8.1.
Oil leakage past spool seal into
spool cap.
•
Remove the cap.
•
If it contains oil, replace spool seal O-rings.
•
Check the O-ring retainer to be sure it is flat. If it
is‘belled’,
check for restriction from outlet to reservoir of the valve,
which would cause excessive back pressure.
•
Check and replace any damaged hoses and lines. Check for
pinched hoses.
•
See important instruction § 7.8.1.
Bent spool.
Replace with new spool section.
See important instruction § 7.8.1.
Foreign particles.
Clean system and valve.
Misalignment of control handle
linkage.
Check linkage for binding conditions.
Spring-centered
spools do not
return to neutral.
Paint on valve spool; sticking
valve spool or scored valve
spool.
Clean valve spool. Binding is usually caused by an over-
tightened plug, mounting bolt, fitting in the valve body, or tie rod
bolt. If a plug or fitting in the valve body leaks, do not over-
tighten to stop the leak. It will distort body casting and cause
spools to bind. Instead, the plug and fitting should be removed
from the valve body and reconnected using a new O-ring.
Do not apply excessive pressure on mounting bolts.
The rods should be torqued to 20 ft./lbs.
Never force the spool; if binding occurs, see important instruction
§ 7.8.1.
Oil leakage past spool seal into
spool cap remove the cap.
If it contains oil, replace spool seal O-rings. Check the O-ring
retainer to be sure it is flat. If it has been
‘belled’, check for
restriction from the outlet to the reservoir of the valve, which
would cause excessive back pressure. See important instruction
§ 7.8.1. or there are restrictions on oil lines; check and replace
any damaged hoses and lines. Check for pinched hoses.
Broken return springs.
Replace springs. See important instruction § 7.8.1.
Bent spool.
•
Replace with new spool section.
•
See important instruction § 7.8.1.
Foreign particles.
Clean system and valve.
Misalignment of control handle
linkage.
Check linkage for binding conditions.
Summary of Contents for BACKHOE BH6
Page 1: ...Operator s Manual BACKHOE SERIES BH6 BH7 BH8 VERSION 2 0 EN 2022...
Page 6: ...Operator s Manual Backhoe Series BH Page 6 of 91 Version 2 0...
Page 89: ...Operator s Manual Backhoe Series BH Page 89 of 91 Version 2 0 Excavation Specifications BH6...
Page 90: ...Operator s Manual Backhoe Series BH Page 90 of 91 Version 2 0 Excavation Specifications BH7...
Page 91: ...Operator s Manual Backhoe Series BH Page 91 of 91 Version 2 0 Excavation Specifications BH8...
