WABCO MICO ACV-DMO-RV, Product Explanation, Operating Information, And Service Instructions

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MICO, Inc.
(6)
Form No. 81-463-019 Revised 2017-06-01
SERVICE CHECKS FOR HYDRAULIC SYSTEMS
ACCUMULATOR CHARGING
CYCLE REPEATS FREQUENTLY
WHEN ACCUMULATOR IS NOT
NORMALLY BEING DISCHARGED
IN SERVICE
1. Leaking accumulator lines or fittings
1. Check lines and fittings for leaks
and correct
2. Incorrect setting of accumulator gas
charge
2. Check accumulator gas charge
3. Line to accumulator plugged
3. Replace line
4. Inoperative charging valve
4. Replace charging valve
ACCUMULATOR STARTS TO
CHARGE BUT DOES NOT REACH
HIGH LIMIT
1. No oil or low oil level in tank
1. Check oil level
2. Pump worn or inoperative and not
delivering full flow or pressure
2. Check pump
3. Inoperative system relief valve (valve
leaking or has low setting so full flow
and pressure are not available)
3. Check relief valve
4. Inoperative charging valve
4. Replace charging valve
ACCUMULATOR CHARGING TIME
TOO LONG
1. No oil or low oil level in tank
1. Check oil level
2. Relief valve setting too low
2. Check valve setting
3. Pump worn or inoperative and not
delivering full flow or pressure
3. Check pump
4. Inoperative charging valve
4. Replace charging valve
ACCUMULATOR FAILS TO START
CHARGING
1. No oil or low oil level in tank
1. Check oil level
2. Worn or inoperative pump
2. Check pump pressure and flow
3. Inoperative relief valve
3. Check relief valve setting
4. Air in accumulator line
4. Bleed accumulator line
5. Inoperative charging valve
5. Replace charging valve
VERY RAPID CYCLING OF
CHARGING VALVE
1. Incorrect setting of accumulator gas
charge
1. Check accumulator gas charge
2. Inoperative charging valve
2. Replace charging valve
LACK OF ADEQUATE FLOW
THROUGH VALVE
1. Inoperative pump
1. Check pump pressure and delivery
2. Inoperative relief valve
2. Check relief valve setting
3. Blocked lines
3. Replace lines
4. Inoperative charging valve
4. Replace charging valve
SERVICE DIAGNOSIS
(Refer to Figure 1)
ACCUMULATOR CHARGING
CYCLE REPEATS FREQUENTLY
WHEN ACCUMULATOR IS NOT
NORMALLY BEING DISCHARGED
IN SERVICE
1. Poppet or ball (28) leaking.
2. O-ring (9) next to seat (27) leaking.
3. O-ring (17) leaking.
4. Ball (20) leaking.
5. Inoperative seat on insert (18).
ACCUMULATOR STARTS TO
CHARGE BUT DOES NOT REACH
HIGH LIMIT
1. O-ring (16) leaking.
2. Seal (4) on spool (3) has been
damaged or worn.
ACCUMULATOR CHARGING TIME
TOO LONG
1. Dirt in filter/screen (25).
2. Poppet or ball (28) or poppets
(34 or 38) stuck, partially closed.
3. Seat (27) partially plugged.
ACCUMULATOR FAILS TO START
CHARGING
1. Broken spring (12).
2. Broken spring (5).
3. Spool (3) stuck.
4. Dirt in filter/screen (25).
VERY RAPID CYCLING OF
CHARGING VALVE
1. Insert (18) worn.
2. Poppets (34 or 38) stuck,
partially closed.
ACCUMULATOR PRESSURES
ARE NOT ISOLATED FROM ONE
ANOTHER
1. O-rings (35 or 37) leaking.
2. Inoperative poppets (34 or 38).
ACCUMULATOR CHARGING
CYCLE REPEATS FREQUENTLY
WHEN ACCUMULATOR IS NOT
NORMALLY BEING DISCHARGED
IN SERVICE
1. Ball (27) leaking.
2. O-ring (9) next to seat (26) leaking.
3. O-ring (17) leaking.
4. Ball (20) leaking.
5. Inoperative seat on insert (18).
ACCUMULATOR STARTS TO
CHARGE BUT DOES NOT REACH
HIGH LIMIT
1. O-ring (16) leaking.
2. Seal (4) on spool (3) has been
damaged or worn.
ACCUMULATOR CHARGING TIME
TOO LONG
1. Ball (27) or poppet (34 or 38) stuck,
partially closed.
2. Seat (26) partially plugged.
ACCUMULATOR FAILS TO START
CHARGING
1. Broken spring (12).
2. Broken spring (5).
3. Spool (3) stuck.
VERY RAPID CYCLING OF
CHARGING VALVE
1. Insert (18) worn.
2. Poppets (34 or 38) stuck,
partially closed.
ACCUMULATOR PRESSURES
ARE NOT ISOLATED FROM ONE
ANOTHER
1. O-rings (35 or 37) leaking.
2. Inoperative poppets (34 or 38).
SERVICE DIAGNOSIS
(Refer to Figure 2)