Toro groundsmaster 455-D - Cutting Unit(S) Drop from Raised Position with Lift Valve in Centered Position; Cutting Units will Not Drop or Follow Ground Contours

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Cutting Unit Will Not Drop or Follow Ground Contours
Cause Correction
Low engine RPM. Adjust engine RPM - use tachometer.
Lift arm or cylinder pivots binding. Lubricate bushings. Inspect for damage. Repair or
re
place damaged parts.
Lift cylinder damaged. Check lift cylinder(s) and repair or replace if
necess
ary.
Counterbalance pressure to high - TEST NO. 2, 3. Adjust counterbalance pressure or replace
co
unterbalance relief valve if necessary.
Orifice in hydraulic line plugged. Clean orifice.
Worn or damaged spool detent in lift valve. Repair or replace.
Faulty lift valve. Repair or replace lift valve.
Cutting Unit Drops From Raised Position With Lift Valve in Centered Position
Cause Correction
Improperly positioned valve. Instruct operator.
Worn detent(s) in lift valve. Repair lift valve.
Internal leakage of lift cylinder(s) Check lift cylinder(s) and repair or replace if
necess
ary.
Lift cylinder hydraulic lines or fittings leaking. Check for leaks. Correct any leaks by replacing
o
-rings and tightening connection properly. Replace
lines or fittings if necessary.
Faulty lift valve lockout assembly. Check for damaged o-rings on lockout plugs or seats
and r
epair if necessary.
Check for damaged or worn lockout poppet assembly
and replace if necessary.
Check for broken lockout spring and replace if
necessary.
Hydraulic System
Groundsmaster
®
455-D Page 4 - 17 Troubleshooting