HomeEnginesJohn Deere 4039T

John Deere 4039T Engine

The John Deere 4039T is a 3.92 L 4-cylinder turbocharged engine rated at 1800 rpm, producing up to 76 kW. It powers generator sets from John Deere and Kohler, including the 4039 and 50ROZ. It holds 13.2 L (3.5 gal) of oil and 18 L (4.8 gal) of coolant.

Also known as: John Deere 4039T

3.92 L
Displacement
4
Cylinders
1800 rpm
Rated speed
76 kW
Gross power

Engine specifications

Oil capacity13.2 L
Coolant capacity18.0 L
Displacement3.92 L
Cylinders4
AspirationTurbocharged
Rated speed1800 rpm
Gross power76 kW

Generator sets powered by this engine

2

Shared across brands: John Deere, Kohler

How to read your John Deere engine serial & model number →

Service intervals

29
ItemActionHoursMonthsNotes
Fire ExtinguisherOther100 hrService
PTO Clutch Shaft BearingLubricate100 hr
PTO clutch shaft bearingsLubricate100 hrOne or two shots of John Deere Multipurpose Lubricant; shaft fittings lubricated at 600 Hours/1-Year
BatteryOther250 hrService
Engine Oil and FilterChange250 hrFirst service — First change after 100 hours max, then every 250 hours; extend by 50 hrs with TORQ-GARD SUPREME PLUS-50 and JD filter
Fan and alternator V-belt tensionCheck250 hrOn engines with dual belts, check tension of front belt only
PTO clutch adjustmentCheck250 hrMeasure clutch engagement force at handle grip
V-Belt TensionCheck250 hr
Engine valve clearanceAdjust1200 hr24 moFirst service — Initial valve clearance adjustment after first 400 hours of operation on new or rebuilt engines
Air Intake HosesCheck600 hr12 mo
Air cleaner elementsReplace600 hr12 moInspect and service; always replace secondary element, never clean it
Air intake hoses and connectionsCheck600 hr12 moTighten hose clamps; inspect hoses for cracks
Air intake systemCheck600 hr12 moService air intake system; inspect dust unloader valve
Coolant solutionTest600 hr12 moCoolant solution analysis (COOLSCAN); add inhibitor as needed
Cooling systemCheck600 hr12 moCheck entire cooling system for leaks; tighten all clamps securely
Crankcase vent tubeClean600 hr12 moClean at shorter intervals in dusty conditions
Fuel filter elementReplace600 hr12 moBleed fuel system after replacement
PTO clutch internal levers and linkageLubricate600 hr12 moApply one shot of John Deere Multipurpose Lubricant to pivot points and release lever shaft fittings
Cooling systemDrain1200 hr24 moFlush cooling system and replace thermostats; fill with recommended clean coolant
Cooling system and radiator capTest1200 hr24 moPressure test cooling system and radiator cap at 50 kPa (0.5 bar) (7 psi)
Crankshaft vibration damperCheck1200 hr24 moReplace damper every 4500 hours or 5 years, whichever occurs first
Engine speedsAdjust1200 hr24 moCheck and adjust engine speeds
Engine tune-upOther1200 hr24 moRecommended every 1200 hours or 2 years, whichever comes first
Fuel injection systemCheck1200 hr24 moCheck engine/injection pump timing, clean injection nozzles, adjust opening pressure
ThermostatsReplace1200 hr24 moRemove and discard thermostats and gasket material; install new gasket and thermostats; tighten cap screws to 27 N-m (20 lb-ft)
TurbochargerInspect1200 hr24 moCheck excessive radial or axial end play of compressor wheel and boost pressure on turbocharged engines
Coolant inhibitors (SCA)Check6 moCheck inhibitors between drain intervals every 6 months or 30,000 miles at low speed operation, or 12 months or 25,000 miles at normal operation; replenish with supplemental coolant additive
Coolant solution (glycol and inhibitor level)Test6 mo6 month/15,000 mile low speed operation or 12 month/25,000 mile normal operation intervals, and whenever excessive coolant is lost through leaks or overheating
Valve clearanceCheckFirst service — Recheck valve clearances after engine break-in and adjust as necessary

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Service specifications

60
TypeItemValueUnitCondition
ClearanceBalancer shaft end play (4-cylinder engines)0.05—0.26mm (0.002—0.010 in.)wear limit 0.38 mm (0.015 in.)
ClearanceBalancer shaft journal-to-bushing oil clearance0.024—0.100mm (0.001—0.004 in.)maximum allowable 0.15 mm (0.006 in.)
ClearanceCamshaft end play0.08—0.23mm (0.003—0.009 in.)wear limit 0.38 mm (0.015 in.)
ClearanceCamshaft thrust plate clearance0.08—0.23mm (0.003—0.009 in.)wear limit 0.38 mm (0.015 in.)
ClearanceConnecting rod bearing-to-journal oil clearance (new parts 3029/4039/6059)0.025—0.102mm (0.0012—0.0040 in.)wear limit 0.152 mm (0.0600 in.)
ClearanceConnecting rod bearing-to-journal oil clearance (new parts 4045/6068)0.050—0.127mm (0.0020—0.0050 in.)wear limit 0.152 mm (0.0600 in.)
ClearanceCrankshaft End Play.001" - .014"in
ClearanceCrankshaft end play (new parts, six-piece thrust bearing)0.025—0.35mm (0.001—0.014 in.)wear limit 0.50 mm (0.020 in.)
ClearanceCrankshaft end play (new parts, two-piece thrust bearing)0.05—0.25mm (0.002—0.010 in.)wear limit 0.50 mm (0.020 in.)
ClearanceCrankshaft main bearing-to-journal clearance0.025—0.102mm (0.0009—0.0040 in.)
ClearanceCrankshaft main or rod journal maximum taper / out-of-round0.010 / 0.005mm (0.0004 / 0.0002 in.)
ClearanceCrankshaft main thrust bearing-to-journal (side) oil clearance0.090—0.217mm (0.0035—0.0085 in.)
ClearanceCylinder Liner Protrusion.001" - .004"in
ClearanceCylinder head flatness - maximum acceptable out-of-flat (entire length or width)0.08mm (0.003 in.)
ClearanceCylinder head flatness - maximum acceptable out-of-flat per 150 mm (5.90 in.)0.03mm (0.001 in.)
ClearanceCylinder head thickness - new104.87—105.13mm (4.129—4.139 in.)minimum acceptable 104.24 mm (4.104 in.)
ClearanceCylinder liner height above block0.030—0.100mm (0.001—0.004 in.)maximum permissible height difference 0.05 mm (0.002 in.)
ClearanceExhaust valve - lift11.28—12.12mm (0.444—0.477 in.)at 0.00 mm (in.) clearance; wear limit 10.85 mm (0.427 in.)
ClearanceExhaust valve - recess in cylinder head1.22—1.72mm (0.048—0.068 in.)worn limit 2.26 mm (0.089 in.)
ClearanceFlywheel housing seal bore maximum permissible run-out0.152mm (0.006 in.)
ClearanceIntake valves - lift11.56—12.37mm (0.455—0.487 in.)at 0.00 mm (in.) clearance; wear limit 11.13 mm (0.438 in.)
ClearanceIntake valves - recess in cylinder head0.61—1.11mm (0.024—0.044 in.)worn limit 1.63 mm (0.064 in.)
ClearancePiston Protrusion.003" - .012"in
ClearancePiston protrusion above block deck (using JDG451 or KJD10123 gauge)0.08—0.31mm (0.003—0.012 in.)
ClearancePiston protrusion above block deck (using magnetic base dial indicator)0.15—0.38mm (0.006—0.015 in.)
ClearancePiston-to-liner clearance (naturally aspirated engines, measured at bottom of piston skirt)0.08—0.14mm (0.003—0.005 in.)
ClearancePiston-to-liner clearance (turbocharged engines, measured at bottom of piston skirt)0.08—0.15mm (0.003—0.006 in.)
ClearanceUpper and lower idler gear end play0.14—0.29mm (0.006—0.012 in.)wear limit 0.40 mm (0.016 in.)
ClearanceValve guide-to-valve stem clearance (new)0.05—0.10mm (0.002—0.004 in.)wear limit 0.15 mm (0.006 in.)
GapAir cleaning gun nozzle distance from perforated metal retainer25.4mm (1.0 in.)
GapTiming gear backlash - camshaft-to-upper idler (helical gears)0.07—0.35mm (0.003—0.014 in.)wear limit 0.51 mm (0.020 in.)
GapTiming gear backlash - injection pump-to-upper idler (helical gears)0.07—0.35mm (0.003—0.014 in.)wear limit 0.51 mm (0.020 in.)
GapTiming gear backlash - upper idler-to-crankshaft (helical gears)0.07—0.30mm (0.003—0.012 in.)wear limit 0.40 mm (0.016 in.)
OtherAir cleaning gun pressure for cleaning primary filter element, maximum210kPa (2.1 bar) (30 psi)
OtherCamshaft follower-to-bore clearance0.06—0.13mm (0.002—0.005 in.)
OtherCamshaft thrust plate thickness3.96—4.01mm (0.156—0.158 in.)wear limit 3.83 mm (0.151 in.)
OtherCrankshaft vibration damper replacement interval4500 hours or 5 years, whichever occurs first
OtherDual V-belt tension, new belt423-467N (95-104 lb force)
OtherDual V-belt tension, used belt378-423N (85-94 lb force)belts are considered used after 10 minutes of operation
OtherLeft-hand auxiliary gear drive, continuous operation30kW (40 hp)
OtherLeft-hand auxiliary gear drive, intermittent operation37kW (50 hp)
OtherOil pressure regulating valve95N·m (70 lb-ft)
OtherPTO clutch engagement force267-311N (60-70 lb force)measured at handle grip with a spring scale
OtherPoly V-belt deflection with 130 N (30 lb force) applied halfway between pulleys13mm (1/2 in.)warm belts
OtherRight-hand auxiliary gear drive, continuous operation11kW (15 hp)
OtherRight-hand auxiliary gear drive, intermittent operation19kW (26 hp)
OtherRinsing water pressure for washing primary filter element, maximum280kPa (2.8 bar) (40 psi)
OtherSingle V-belt tension, new belt578-622N (130-140 lb force)
OtherSingle V-belt tension, used belt378-423N (85-94 lb force)belts are considered used after 10 minutes of operation
OtherStandard V-belt deflection with 89 N (20 lb force) applied halfway between pulleys19mm (3/4 in.)warm belts
OtherTachometer drive gear (knurled end) OD12.88—12.92mm (0.506—0.508 in.)
OtherValve face angle29.25degrees ±0.25
PressureCooling system pressure test50kPa (0.5 bar) (7 psi)
PressureMaximum air intake restriction6.22kPa (0.06 bar) (1.0 psi) (25 in. H2O)
PressureMinimum oil pressure at 850 rpm (3-cylinder engines)140kPa (1.4 bar) (20 psi)at 850 rpm
PressureMinimum oil pressure at 850 rpm (except 3-cylinder)103kPa (1.03 bar) (15 psi)at 850 rpm
PressureNormal engine oil pressure380 +/- 103kPa (3.80 bar +/- 1.03 bar) (55 +/- 15 psi)at rated full load speed (1800-2500 rpm) with oil at normal operating temperature of 105 C (220 F)
PressureRadiator cap pressure test50kPa (0.5 bar) (7 psi)gauge should hold pressure for 10 seconds
SpeedFast idle speed (generator set governor)3-5% above rated speedrpm
SpeedFast idle speed (standard governor)7-10% above rated speedrpm

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Recommended fluids

FluidGradeStandardAmbientCapacityNotes
Coolant50/50 mixture of quality water and ethylene glycol concentrate (antifreeze) plus 3% (by volume) supplemental coolant additives (SCA's)Ethylene glycol concentrate meeting ASTM D5345 (prediluted coolant) or ASTM D4985 (coolant concentrate)John Deere Prediluted Antifreeze/Summer Coolant, John Deere Antifreeze/Summer Coolant Concentrate, John Deere Low Silicate Antifreeze, or John Deere COOL-GARD. Freeze protection limits by % concentrate: 40% = -24 C (-12 F); 50% = -37 C (-34 F); 60% = -52 C (-62 F).
CoolantWater quality specification for mixing with coolant concentrateChlorides max 40 ppm (2.5 grains/US gal); Sulfates max 100 ppm (5.9); Total dissolved solids max 340 ppm (20); Total hardness max 170 ppm (10); pH 5.5—9.0Distilled, deionized or demineralized water recommended. Water may be used as coolant in emergency situations only.
CoolantJohn Deere PREDILUTED ANTIFREEZE/SUMMER COOLANT, John Deere COOL-GARD, or John Deere ANTIFREEZE/SUMMER COOLANT CONCENTRATE (low silicate ethylene glycol + SCAs); otherwise low silicate ethylene glycol base coolantASTM D5345 (prediluted coolant) or ASTM D4985 (coolant concentrate)above -52°C40% concentrate = -24 C (-12 F); 50% = -37 C (-34 F); 60% = -52 C (-62 F). Do not use automotive-type coolants meeting ASTM D3306 or ASTM D4656. Do not use soluble oil. Coolants meeting ASTM D5345/D4985 require an initial charge of supplemental coolant additives.
CoolantJohn Deere Prediluted Antifreeze/Summer Coolant, Antifreeze/Summer Coolant Concentrate, Low Silicate Antifreeze, or COOL-GARDabove 52°C50/50 mixture of water and ethylene glycol antifreeze plus 3% by volume SCA; 60% concentrate gives -52°C (-62°F) protection
Engine oilJohn Deere ENGINE BREAK-IN OIL; if not available, API Service Classification CE or ACEA Specification E1API CE, ACEA E1Use during the first 100 hours of operation of a new or rebuilt engine. Do not use PLUS-50 or oils meeting API CG4, API CF4, ACEA E3 or ACEA E2 during break-in.
Engine oilJohn Deere Engine Break-In OilFactory fill; drain after first 100 hours of operation; do not use TORQ-GARD SUPREME PLUS-50 during the first 100 hours of operation after an engine rebuild
Engine oilJohn Deere PLUS-50 engine oil preferred; API Service Classification CG-4 or CF-4; ACEA Specification E3 or E2API CG-4, API CF-4, ACEA E3, ACEA E2Multi-viscosity diesel engine oils preferred. If PLUS-50 oil and a John Deere oil filter are used, the oil and filter service interval may be extended by 50%. If diesel fuel sulfur content is greater than 0.5%, reduce the service interval by 50%.
Engine oilJohn Deere TORQ-GARD SUPREME PLUS-50 (preferred); TORQ-GARD SUPREME; UNI-GARD; API CE or CDAPI CE / API CD / CCMC D5 / CCMC D4Break-in oil used for first 100 hours; do not use TORQ-GARD SUPREME PLUS-50 during first 100 hours after rebuild
Engine oilJohn Deere TORQ-GARD SUPREME oil also recommendedSelect oil viscosity based on the expected air temperature range during the period between oil changes. Temperature limits and service intervals apply to both conventional and synthetic oils.
Engine oilJohn Deere TORQ-GARD SUPREME PLUS-50 (preferred); John Deere TORQ-GARD SUPREME; John Deere UNI-GARD; or oil meeting API CE, API CD, CCMC D5, CCMC D4API Service Classification CE or CD; CCMC Specification D5 or D4-40°C to 50°CUse oil viscosity based on expected air temperature range. Arctic oils (MIL-L-46167B) may be used below -30 C (-22 F). If John Deere TORQ-GARD SUPREME PLUS-50 oil and a John Deere oil filter are used, oil and filter service interval may be extended by 50 hours. If diesel fuel sulfur content is greater than 0.5%, reduce engine oil and filter service interval by 50%.
FuelDiesel fuelEN 590 or ASTM D975Cetane number 40 minimum (greater than 50 preferred, especially below -20 C or above 1500 m). Sulfur content should not exceed 0.5%; less than 0.05% preferred; DO NOT use fuel with sulfur content greater than 1.0%. Cold Filter Plugging Point below expected low temperature, or Cloud Point at least 5 C (9 F) below expected low temperature. Fuel lubricity should pass a minimum of 3100 gram load level by BOCLE scuffing test. Bio-diesel meeting DIN 51606 or equivalent may be used. DO NOT mix used engine oil or any other lubricant with diesel fuel.
FuelDiesel fuel; Grade No. 1-D fuel best suited below 5 C (40 F)Military Specification VV-F-800E preferred in North America; EN 590 in most European countries; ASTM D975Cetane number 40 minimum (greater than 50 preferred, especially below -20 C or above 1500 m). CFPP below expected low temperature or cloud point at least 5 C below expected low temperature. Sulfur content should not exceed 0.5% (less than 0.05% preferred); do not use diesel fuel with sulfur content greater than 1.0%. Lubricity must pass BOCLE scuffing test at 3300 gram minimum load level.
FuelDiesel per VV-F-800E (North America) or EN 590 (Europe); ASTM D975 minimum Cetane 40VV-F-800E / EN 590 / ASTM D975Sulfur content should not exceed 0.5%; never exceed 1.0%; reduce oil/filter interval by 50% if sulfur >0.5%
GreaseJohn Deere HIGH TEMPERATURE EP GREASE, John Deere MOLY HIGH TEMPERATURE EP GREASE, or John Deere GREASE-GARDNLGI Performance Classification GC-LBUse grease based on NLGI consistency numbers and expected air temperature range during the service interval.
GreaseJohn Deere MOLY HIGH TEMPERATURE EP; John Deere HIGH TEMPERATURE EP GREASE; John Deere GREASE-GARD; John Deere BIO-GREASE-GARDNLGI Performance Classification GC and LB-30°C to 50°CArctic greases (MIL-G-10924F) may be used at temperatures below -30 C (-22 F)
GreaseJohn Deere MOLY HIGH TEMPERATURE EP GREASE, HIGH TEMPERATURE EP GREASE, GREASE-GARD, or BIO-GREASE-GARDNLGI GC and LBabove 30°CArctic grease MIL-G-10924F below -30°C (-22°F)
OtherJohn Deere Liquid Coolant Conditioner (supplemental coolant additive)non-chromate inhibitorDo not over-inhibit antifreeze solutions (causes silicate-dropout). If a system is filled with coolant that does not contain SCAs, precharge with 3% John Deere Coolant Conditioner.
OtherJohn Deere PREMIUM DIESEL FUEL CONDITIONERAdd at specified concentration if fuel of low or unknown lubricity is used. Available in winter and summer formulas.
OtherJohn Deere TY22030 All Season Diesel Fuel ConditionerTreat Grade No. 2-D fuel before temperature drops to 0 C (32 F); can also be used to treat No. 1-D fuel; reduces fuel gelling and lowers pour point of untreated fuel from 5 C (40 F) to less than -40 C (-40 F)

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Procedures

12
Check PTO Clutch Adjustment adjustment

⚠ Never attempt to service the PTO while it is in operation

⚠ Improper adjustments of the PTO clutch may shorten clutch life

Tools: Spring scale

  1. Measure clutch engagement force at handle grip using a spring scale. Engagement force should be 267-311 N (60-70 lb force).
  2. If adjustments are needed, disengage clutch and stop engine. Remove cover plate from clutch housing.
  3. Remove adjusting lock.
  4. Turn adjusting ring to adjust clutch engagement pressure.
  5. Measure engagement force at clutch handle with spring scale.
  6. Install adjusting lock and tighten screw securely.
  7. Install cover plate and recheck clutch engagement force.
Check and Adjust Engine Valve Clearance adjustment

⚠ Valve clearance must be checked/adjusted with engine cold

Tools: JD281A, JDE83, or JDG820 Engine Rotation Tool, JDE81-4 Timing Pin, feeler gauge

  1. Remove rocker arm cover and crankcase ventilator hose.
  2. Remove plugs or cover plate from flywheel housing timing holes.
  3. Rotate engine clockwise using engine rotation tool and timing pin until No. 1 cylinder is at TDC compression, insert timing pin.
  4. Adjust valve clearance per firing order for 3-, 4-, or 6-cylinder engine: Intake 0.35 mm (0.014 in.), Exhaust 0.45 mm (0.018 in.).
  5. If rocker arm has adjusting screw and jam nut, tighten jam nut to 27 N·m (20 lb-ft) after adjusting clearance.
  6. Install rocker arm cover with new gasket.
Check and Adjust Valve Clearance adjustment

⚠ To prevent accidental starting, always disconnect NEGATIVE (-) battery terminal before valve adjustment.

⚠ Valve clearance MUST be checked and adjusted with engine COLD.

Tools: JDE83 or JDG820 Flywheel Turning Tool, JDE81-4 Timing Pin, Feeler gauge, Torque wrench

  1. Disconnect NEGATIVE (-) battery terminal; remove rocker arm cover and crankcase ventilator tube.
  2. Remove plastic plug or cover plate from engine rotation/timing holes.
  3. Using JDE83 or JDG820 Flywheel Turning Tool, rotate flywheel in running direction until No. 1 cylinder is at TDC compression stroke.
  4. If No. 1 rocker arms are loose, engine is at No. 1 TDC compression; otherwise rotate one full revolution.
  5. Insert JDE81-4 Timing Pin in flywheel.
  6. Check intake clearance 0.31—0.38 mm (0.012—0.015 in.) and exhaust 0.41—0.48 mm (0.016—0.019 in.) cold.
  7. Loosen locknut on rocker arm adjusting screw; turn screw until feeler gauge slips with slight drag.
  8. Hold adjusting screw and tighten locknut to 27 N•m (20 lb-ft); recheck clearance.
  9. Adjust intake to 0.36 mm (0.014 in.) and exhaust to 0.46 mm (0.018 in.) cold.
Measure Cylinder Liner Standout (Height Above Block) adjustment

⚠ ONE LINER SHIM ONLY may be installed under each liner flange. If liner requires more than one shim, install a new liner or cylinder block.

Tools: JDG451 or KJD10123 Height Gauge, D17526CI or D17527CI Dial Indicator, KCD10001 or JDG1145 Cylinder Liner Puller

  1. Be sure liner bore in cylinder block and top deck of block are clean.
  2. Install liner without O-rings and packing; liner should rotate smoothly by hand.
  3. Locate liner mark toward front of engine; secure with cap screws and washers tightened to 68 N•m (50 lb-ft).
  4. Using JDG451 or KJD10123 Gauge and D17526CI or D17527CI Dial Indicator, measure liner height at 1, 5, 7 and 11 o'clock positions viewed from flywheel end.
  5. Record measurements by cylinder number and compare with specification.
  6. If liner height is no more than 0.08 mm (0.003 in.) below top deck of block, install one liner shim under liner flange.
  7. Remove and shim or replace any liner that does not meet height specifications.
Check Crankshaft End Play diagnostic

⚠ Do not apply too much pressure with the bar, as this could damage bearings.

Tools: Dial indicator, Prybar

  1. Position dial indicator on contact face of flywheel, front crankshaft nose, damper or front pulley assembly.
  2. Using a prybar, gently push crankshaft as far to rear of engine as possible.
  3. Zero the dial indicator.
  4. Gently pry the crankshaft as far forward as possible.
  5. Note indicator reading; if end play is not within specifications, install new thrust bearing.
Measure Valve Lift diagnostic

⚠ Measure valve lift at 0.00 mm (in.) rocker arm-to-valve tip clearance for accuracy.

Tools: JDG820 or JDE83 Flywheel Turning Tool, JDE81-4 Timing Pin, Dial indicator, Feeler gauge

  1. Remove rocker arm cover.
  2. Lock No. 1 piston at TDC compression stroke.
  3. Set rocker arm-to-valve tip clearance to 0.00 mm (in.) for the specified valves.
  4. Place dial indicator tip on top of valve spring retainer or rotator; preload and set dial at 0.0 mm.
  5. Remove timing pin and rotate engine one full revolution (360°) in running direction.
  6. Observe dial indicator reading at full open; record maximum and compare with specifications.
  7. Repeat for remaining valves after rotating one revolution to the appropriate TDC.
Pressure Test Cooling System and Radiator Cap diagnostic

⚠ Do not apply excessive pressure to cooling system; doing so may damage radiator and hoses

Tools: Approved cooling system tester, Gauge and adapter

  1. Remove radiator cap and attach to an approved tester.
  2. Pressurize cap to 50 kPa (0.5 bar) (7 psi). Gauge should hold pressure for 10 seconds within the normal range if cap is acceptable.
  3. If gauge does not hold pressure, replace radiator cap.
  4. Remove the cap from gauge, turn it 180 degrees, and retest cap.
  5. For cooling system test: allow engine to cool, then carefully remove radiator cap.
  6. Fill radiator with coolant to the normal operating level.
  7. Connect gauge and adapter to radiator filler neck. Pressurize cooling system to 50 kPa (0.5 bar) (7 psi).
  8. With pressure applied, check all cooling system hose connections, radiator, and overall engine for leaks.
Bleed the Fuel System maintenance

⚠ Escaping fluid under pressure can penetrate the skin causing serious injury. Relieve pressure before disconnecting fuel or other lines

⚠ If any fluid is injected into the skin, it must be surgically removed within a few hours

Tools: Two wrenches

  1. Loosen the air bleed plug or air bleed screw on fuel filter base.
  2. When equipped, operate supply pump primer lever or switch on the ignition (electric supply pumps).
  3. Wait until fuel flow is free from air bubbles. Tighten bleed plug or screw securely, continue operating hand primer until pumping action is not felt. Push hand primer inward.
  4. If engine will not start, slightly loosen fuel supply line connector at injection pump.
  5. Pump hand primer lever until fuel without air bubbles flows from fuel supply line connection.
  6. Tighten supply line connector to 27 N-m (20 lb-ft).
  7. Leave hand primer in the inward position toward cylinder block.
  8. If engine still will not start, move speed control lever to slow idle.
  9. While cranking engine, loosen one fuel line connector slightly using two wrenches until fuel free of air bubbles flows. Tighten connector while cranking.
  10. Repeat procedure for remaining injection nozzles until engine starts and air has been removed.
Change Engine Oil and Filter maintenance

⚠ Do not overtighten filter element

  1. Run engine approximately 5 minutes to warm up oil, then shut off.
  2. Drain oil while warm from crankcase.
  3. Remove and discard oil filter element; clean filter mounting pad.
  4. Oil new packing and install new filter element; hand tighten per values on filter, or approximately one turn after packing contacts housing.
  5. Install drain plug with new seal if equipped.
  6. Fill crankcase with correct John Deere engine oil.
Cleaning Primary Filter Element maintenance

⚠ Do not blow air from outside portion of filter with air nozzle. Wear safety glasses and remove bystanders

⚠ Only a special air cleaning gun should be used

Tools: Special air cleaning gun

  1. Gently pat sides of element with palm of hand to loosen dirt. Do not tap element against a hard surface.
  2. Insert the cleaning gun into element, hold air nozzle about 25.4 mm (1.0 in.) from perforated metal retainer.
  3. Force air through filter from inside to outside and move air gun up and down pleats to remove as much dirt as possible.
  4. Repeat steps 1 and 2 to remove additional dirt.
  5. Inspect element for damage after cleaning. Replace element if any damage is found.
Fan and Alternator Belts Tension or Replacement maintenance

⚠ Do not pry against the alternator rear frame

⚠ Do not tighten or loosen belts while they are hot

Tools: JDG529 Tension Gauge, Belt tension tester, Straightedge

  1. Inspect belts for cracks, fraying, or stretched out areas. Replace if necessary.
  2. Using JDG529 Tension Gauge or belt tension tester and straightedge, check tension of warm belts.
  3. If adjustment is necessary, loosen alternator bracket cap screw and nut on mounting bolt. Pull alternator frame outward until belts are correctly tensioned.
  4. Tighten alternator bracket cap screw and nut firmly.
  5. After a new or used belt has run for 10 minutes, recheck belt tension.
Flush Cooling System and Replace Thermostats maintenance

⚠ Explosive release of fluids from pressurized cooling system can cause serious burns. Only remove filler cap when cool enough to touch with bare hands

⚠ Air must be expelled from cooling system when system is refilled

  1. Slowly open the cooling system filler cap or radiator cap to relieve pressure.
  2. Open radiator drain valve. Drain all coolant from radiator.
  3. On left side of engine, open drain valve or remove drain plug from engine block. Drain all coolant from engine block.
  4. Close all drain valves after coolant has drained.
  5. Fill the cooling system with clean water. Run the engine about 10 minutes to stir up possible rust or sediment.
  6. Stop engine and immediately drain the water before rust and sediment settle.
  7. Fill the cooling system with clean water and TY15979 John Deere Heavy Duty Cooling System Cleaner or equivalent cleaner.
  8. Fill with water to flush the system. Run engine about 10 minutes, then drain flushing water.
  9. For thermostat replacement, remove cap screws and thermostat cover.
  10. Remove and discard thermostats and all gasket material.
  11. Install new gasket, new thermostats and cover. Tighten all cap screws to 27 N-m (20 lb-ft).
  12. Add coolant to radiator until coolant touches bottom of filler neck.
  13. Run engine until it reaches operating temperature; normal coolant temperature range is 82-94 C (180-202 F).
  14. After running engine, check coolant level and entire cooling system for leaks.

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Aftermarket parts that fit this engine

37

Parts listed by aftermarket suppliers as fitting this engine — leads compiled from supplier catalogs; verify the exact part for your serial number.

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  • John Deere 6300 — Tractor
  • John Deere 6500 — Sprayer
  • Vermeer T450 — Trencher

Other equipment known to use this engine, via filter-application cross-reference — useful for sourcing parts even when your exact machine isn't listed elsewhere on this page.

Common questions

What is the oil capacity of the John Deere 4039T?

The John Deere 4039T engine has an oil capacity of 13.2 liters.

What is the displacement of the John Deere 4039T?

The John Deere 4039T has a displacement of 3.92 liters with 4 cylinders.

Which generators use the John Deere 4039T engine?

The John Deere 4039T powers 2 generator set(s), including John Deere 4039, Kohler 50ROZ.