HYDRAULICS
SECTION 8B. FAILURE ANALYSIS
8B-2
PROBLEM PROBABLE CAUSE REMEDY
7. No differential lock. a. Faulty cartridge valve. a. Replace (Section 8K).
Check LED in differential b. Faulty 4 wheel drive control valve b. Repair/replace (Section 8F).
lock solenoid plug: spool.
ON — Switch solenoid c. Insufficient charge pressure to c. Test (Section 8R).
with 4 wheel drive activate 4 wheel drive valve.
solenoid. Still no
d. Faulty differential lock valve d. Replace (Section 8K).
differential lock,
spool.
see a to e.
e. Faulty differential lock cylinder. e. Repair (Section 4E).
OFF — See f,
f. Faulty electrical circuit. f. See Section 10B.
8. Differential lock not a. Differential collar sticks in axle. a. Let up on traction pedal.
disengaging. Tractor should not be in a turn.
b. Differential solenoid valve spool b. Replace (Section 8K).
sticks.
c. Differential solenoid does not c. See Section 10B.
de-energize.
d. Insufficient charge pressure to d. Test (Section 8R).
activate differential lock.
e. Differential collar return spring e. Repair (Section 4E).
broken.
LIFT SYSTEM
1. Mowers will not lower. a. Engine RPM must be 2000 or a. Increase engine RPM to 2000.
greater.
b. Valve detent spool sticks. b. Repair (Section 8H).
c. Faulty lift valve main relief. c. Test/adjust (Section 8R).
d. Insufficient oil supply, priority d. Test (Section 8R).
valve.
e. Mechanical binding of lift arm. e. Lubricate/repair (Sections
11B, 9F).
f. Faulty pump. f. Test (Section 8R).
2. Mowers lower too slow. a. Flotation control set too high. a. Adjust (see Operator’s Manual.
b. Restriction in oil return line. b. Check (Section 8S).
3. Right wing will not lower. a. Mechanical binding of lift arm. a. Lubricate/repair (Sections
11B, 9F).
b. Valve detent spool sticks. b. Repair (Section 8H).
c. Restriction in oil return line. c. Test (Section 8R).
4. Left wing will not lower. a. Mechanical binding of lift arm. a. Lubricate/repair (Sections
11B, 9F).
b. Valve detent spool sticks. b. Repair (Section 8H).
c. Restriction in oil return line. c. Test (Section 8R).