Accumulator Charge Troubleshooting - JLG sky trak mmv Service Manual

9.13.4

Accumulator Charge Troubleshooting

Problem
1. Accumulator charging cycle
repeats frequently when
accumulator is not normally
being discharged
2. Accumulator starts to charge
but does not reach high limit
3. Accumulator charging time
too long
Model MMV Rev. 12/04
Cause
1. Leaking accumulator lines or
fittings.
2. Incorrect settings of
accumulator gas charge.
3. Line to accumulator plugged.
4. Inoperative accumulator
charging valve.
1. No oil or low oil level in hydraulic
reservoir.
2. Pump worn or inoperative and
not delivering full flow or
pressure.
3. Inoperative relief valve in
accumulator charge valve. Valve
leaking or has low setting so full
flow and pressure are not
available.
4. Inoperative accumulator
charging valve.
1. No oil or low oil level in hydraulic
reservoir.
2. Relief valve setting to low.
3. Pump worn or inoperative and
not delivering full flow or
pressure.
4. Inoperative accumulator
charging valve.
Hydraulic System
Remedy
1. Check lines and fittings for leaks
and correct.
2. Check accumulator gas charge.
Refer to Section 9.13.2, Pre-
Charging Accumulator .
3. Replace line.
4. Replace accumulator charging
valve.
1. Check oil level and add oil as
needed.
2. Check pump flow and pressure.
Refer to Section 9.7, Hydraulic
System Testing .
3. Check relief valve and/or
replace. Refer to Section
9.12.10, Accumulator Charge
Valve .
4. Replace accumulator charging
valve.
1. Check oil level and add oil as
needed.
2. Check relief valve setting. Refer
to Section 9.7, Hydraulic
System Testing .
3. Check pump flow and pressure.
Refer to Section 9.7, Hydraulic
System Testing .
4. Replace accumulator charging
valve.
9.139