Danfoss Series 42 User manual

MAKING MODERN LIVING POSSIBLE
Service Manual
Series 42
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Property of American Airlines

Service Manual Series 42 Axial Piston Closed Circuit Pumps
Initial Start-Up Procedure
General
Start-up procedure
Follow this procedure when starting-up a new Series 42 installation or when restarting an installation in
which the pump has been removed.
,.S Warninq
Unintended mcvement of the rnachine or mechanism may cause injury to the technician or bystanders.
To protect against unintended movement, secure the machine or disable/disconnect the mechanism
while servicinq.
Prior to installing the pump, inspect for damage incurred during shipping. Make certain all system
components (reservoir, hoses, valves, fittings, heat exchanger, etc.) are clean prior to filling with fluid.
1. Connect the pump to the prime mover. Ensure that pump shaft is properly aligned with the shaft of
the prime mover.
r& fautior.r
Incorrect sltaft alignment may result in damage to drive shaft, bearings, or seal which can caLtse
external oil leakage.
2. Fill the reservoir with recommended hydraulic fluid. Always filter fluid through a 10 micron absolute
filter pouring into the reservoir. Never reuse hydmulic fluid.
3. Fill the main pump housing with clean hydraulic fluid. Pour filtered oil directly into the upper most
case drain port.
4. Fill the inlet line leading from the pump to the reservoir. Check the inlet line for properfy tightened
fittings and be certain it is free of restrictions and air leak.
5. To ensure the pump stays filled with oil, install the case drain line in the upper most case drain port.
6. Install a gauge at port M2 to monitor system pressure during start up.
Follow recommendations in the vehicle/machine operator's manualfor prime mover start up
procedures.
7. While watching the pressure gauge at M2, jog the prime mover or run at the lowest possible speed
until system pressure builds to normal levels (minimum 1 1 bar tl60 psil). Once system pressure is
established, increase to full operating speed. lf the pump does not maintain system pressure, shut
down the prime mover, determine cause, and take corrective action. Refer to Troubleshooting.
8. Operate the hydraulic system for at least fifteen minutes under light load conditions.
9. Check and adjust control settings as necessary after installation. Refer to Adjustments.
10. Shut down the prime mover and remove the pressure gauge. Replace plug at port M2.
11. Check the fluid level in the reservoir add clean filtered fluid if necessary.
The pump is now readyfor operation.
52010638 . Rev 0300 . July 20'15
Property of American Airlines

Service Manual Series 42 Axial Piston Closed Circuit Pumps
Adjustments
Frame size cm3 28132 4v51
Control MDC/EDC/HC-EDC NFP MDC/EDC/HC-EDC NFP
Lock nut mm 13 17 t7 17
Servo adjust screw mm [in] 5777
Lock nut torque N.m flbf.ft ]231171 40 [30] 40 [30] 40 [30]
Control n€ullal adjustment for MDC and EDC/HC-EDC
Control neutral adjustment aligns the pump swashplate andthe controlspoolso that a zeto angle
contfolsetting provides a zero degree swashplate setting. Perform this adjustment wheneveryou adjust
or move any part of the control or swashplate mechanlsm or afEr you adJust the pump neutral settlng.
,A wurn,no
The following proceciure requires the vehicle/nrachine to be cjisabled (wheels raised off the ground, work
functiotr discannected, etc.) r,nrhile performing the 6rrocedure in order to prevent injury to the technician
and llvstanders.
1. Disconnect the externalcontrol linkage (for MDC) or controlsignalinput (for EDC and HC-EDC)from
the pump,
2. Install pressure gauges in the servo gauge ports M4 and M5 to measure pressure on the pump servo
piston.
3. Startthe prime mover and run at normaloperating speed.
4. Loosen the control neutral adjustment seal lock nut (D015).
5. Turn the adjustment screw (D014) clockwise untilone of the gauges registers an increase in pressure
on the servo piston. Mark the position of the adjustment screw.
Turn the screw counterclockwise until the other gauge registers an increase in pressure on the servo
piston. Mark the position of the adjustment screw.
Turn the adjustment screw clockwise so that it is midway between the marks. Adjustment screw
movement produces constant change for both directions, so both the pressure gauges should
indicate nearly equal pressures.
6. While holding the adjustment screw (D014) in position, torque the seal lock nut (D015) to 04 N.m [30
tbf.ft].
7. Stop the prime mover and remove the pressure gauges. Remove the plugs in the gauge ports.
8. Connect the external control linkage (for MDC) or control signal input (for EDC and HC-EDC) to the
pump. Reconnect the work function.
520L0638 . Rev 0300 'July 201 5
Property of American Airlines

Service Manual Series 42 Axial Piston Closed Circuit Pumps
Adjustments
Control n e utral a dj u st m ent s crew
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Equalization of pressure gouges using pump neutral adjustment screw
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34 520L0638 . Rev 0300. July 201 5
Property of American Airlines

Service Manual Series 42 Axial Piston Closed Circuit Pumps
Troubleshooting
Overyiew
This section provides generalsteps to follow if you observe certain undesirable system conditlons, Some
ofthe items are system speclflc. Always observe the safety precautlons listed in the introduction of this
manual. lf5tandard troubleshooting procedures do not remedythe problem, contact a Danfoss Global
Service Panner.
System opelating hot
Item' Description Action
Oil level in reservoir Insufficient hydraulic fl uid will not
meet the cooling demands of system. Fill the reservoir to the proper level
with clean hydraulic oil.
Heat exchanger (if equipped) The heat exchanger is not sufficiently
cooling the system. Check the air flow and input air
temperature for the heat exchanger.
Clean, repair, or replace the heat
exchanger as necessary.
Bypass valve A partially activated bypass valve may
result in heat generation within the
system.
Verify that the bypass valve is fully
closed and that the valve is seating
properly. Repair or replace it as
necessary.
SCR (System Check/ Reliefl Valves A partially activated SCR valve or SCR
valves with relief settings too low may
result in heat generation within the
system.
Verifli that the SCR valve is seating
properly and is at the correct relief
setting. Repair or replace it as
necessary.
Oilfilters Clogged oil filters may result in an
insufficient supply of cool oilto the
system.
Inspect the oil filters and verify that
they are still operable. Replace them if
necessary.
Machine load Excessive loads or extreme duty rycles
could result in the pump and/ or motor
operating at speeds and pressures
beyond system design limitations.
Veriff that the machine is operating
within the parameters for which it was
designed. lf necessary, reduce the load
on the machine.
System response is sluggish
Item Description Action
Reservoir oil level There is an insufficient amount of
hydraulic fluid, resulting in an
inadequate supply for the system loop.
Fill the reservoir to the proper level
with clean hydraulic fluid.
Input control signal (linkage,
current, or pressure) The pump is receiving a faulty control
signal: (MDC - binding or broken
linkage; EDC - faulty or inadequate
electrical signal; HDC' blocked or
incorrectly orificed control lines).
Veriff that the input signal is correct
and identical in both directions.
Pump control A damaged pump control or control
spoolwill not correctly transmit the
control input signalto the pump.
Verify that the pump's control is
operating properly and that the
controlspool is not damaged orworn
and moves freely within its bore. Clean,
repair, or replace it as necessary.
Bypass valve A partially activated bypass valve will
cause cross port leakage. Veriff that the bypass valve is closed
and that the valve is seating properly.
Clean, repair, or replace it as necessary.
SCR (system check / reliefl valves One or both of the SCR valves may be
binding within their bores. Veriff that the SCR valves operate
freely. Repair or replace them as
necessary.
520L0638 . Rev 0300 . July 201 5
Property of American Airlines

Service Manual Series 42 Axial Piston Closed Circuit Pumps
Troubleshooting
System will not operate in either direction
Item Descfiption Action
Charge pressure (in neutral) The is low charge pressure resulting
from a damaged charge pump or low
charge pressure relief valve setting.
Inspect the charge pump for damage
and verifiTthe charge pressure relief
valve setting. Repair or replace it as
necessary.
Charge pressure (in stroke) There is low charge'pressure resulting
from internalleakage within the
system.
Repair or replacethe component or
components within the system causing
the internal leakage.
Servo pressure There is insufficient pressure
differential across the servo piston. Check servo pressures at port M4 and
M5 to veriff sufficient pressure delta.
Veriff that the servo supply and drain
paths are unobstructed and that any
orifices are of the correct size and free
of debris. Clean, repair, or replace as
necessary.
Charge pump The charge pump has been damaged
or installed with the incorrect
rotational orientation.
Verifo that the charge pump is in good
working order and that it is correctly
installed. Repair or replace it as
necessary.
Item Description Actioh
Oillevelin reservoir There is insufficient hydraulic fluid to
supply the system loop. Fill the reservoir to the proper level
with clean hydraulic oil.
Input controlsignal
(linkage, current, or pressure) The pump is receiving a faulty control
signal: (MDC - binding or broken
linkage; EDC - faulty or inadequate
electrical signal; HDC - blocked or
incorrectly orificed control lines).
Veriry that the input signal is correct
and identical in both directions. Adjust,
clean, repair, or replace the input
device as necessary.
Oilfilters Clogged oilfilters may result in an
insufficient supply of oil to the system. Inspect the oil filters and verifi7 that
they are still serviceable. Replace them
as necessary.
Bypass valve A partially activated bypass valve may
result in a cross port leakage. Verifi7 that the bypass valves are closed
and that the valves are seating
properly. Clean, repair, or replace them
as necessary.
Charge pressure
{in neutral) Charge pressure may be insufficient to
recharge the system loop. Inspect the charge pump for damage
and verifi7 that the charge pressure
relief rralve is at the proper setting.
Repair or replace it as necessary.
Charge pressure
(in stroke) There is low charge pressure resulting
from internal leakage within the
system.
Repair or replace the component or
componenls within the system causing
the internalleakage.
Servo pressure There is an insufficient pressure
differential across the servo piston. Check servo pressures to verifi7
sufficient pressure delta. Verifi7 that the
servo supply and drain paths are
unobstructed and that any orifices are
of the correct size and free of debris.
Clean, repair, or replace them as
necessary.
Charge pump The charge pump is damaged or has
been installed with the incorrect
rotational orientation. a
Veriff that the charge pump is in good
working order and that it is correctly
installed. Repair or replace it as
necessary.
520L0638 . Rev 0300 . July 201 5
Property of American Airlines

Service Manual series 42 Axial Piston closed circuit Pumps
Troubleshooting
System will not operate in one direction
Neutral difficult or impossible to find
Item Description Action
SCR (system check/ reliefl valves The SCR valves are malfunctioning or
improperly set. Verify that the SCR valves are operating
and properly set. Repair or replace
them as necessary.
Displacement limiters Displacement limiters may be
improperly adjusted such that the
servo piston is locked in place.
Veri[t that the displacement limiters
are adjusted to the proper setting.
Item Description Action
Input control signal (linkage,
current, or pressure) The pump is receiving a faulty control
signah (MDC - binding or broken
linkage; EDC - faulty or inadequate
electricalsignal; HDC - blocked or
incorrectly orificed control lines).
Verifu that the input signal is correct
and identical in both dlrections. Adjust,
clean, repair, or replace the control
module as necessary.
SCR (System Check/Relie0 valves The SCR valves are malfunctioning or
improperly set. Veriff that the SCR valves are operating
properly. Repair or replace them as
necessary.
Pump control A damaged or biased pump control
may be sending a signal commanding
the pump to stroke only in one
direction.
Veri$r that the pump's control is
functioning properly. Repair or replace
it as necessary.
Servo pressure The drain or supply path to one side of
the servo piston may be bfocked. Veriff that the servo supply and drain
paths are unobstructed and that any
orifices are of the correct size and free
of debris. Clean or repair them as
necessary.
Displacement limiters (if
equipped) The displacement limiters may be
improperly adjusted such that the
servo piston is prevented from moving
in one direction.
Verifu that the displacement limiters
are adjusted properly.
Item: Description Action
Input control signal (linkage,
current, or pressure) The pump is receiving a faulty control
signal: (MDC - binding or broken
linkage; EDC -faulty or inadequate
electricalsignah HDC - blocked or
incorrectly orifi ced control lines).
Veriff that the input signal is correct
and identical in both directions. Adjust,
clean, repair, or replace control module
as necessary.
System pressure With no input signal to the control, a
pressure delta may exist between the
two sides of the working loop.
Readjust pump neutral setting. Refer to
adjustment procedure.
Servo pressure With no input signalto the control, a
pressure delta may exist across the
seruo piston.
Readjust the controf neutral setting.
Refer to adjustment procedure.
PCP pressure (EDCs only) Wth no input signalto the control, a
pressure difference may exist across
the controlspool.
Replace the EDC.
52010638 . Rev 0300 . July 201 5
Property of American Airlines