ENGINE HARD TO START OR WILL NOT START

Fuel in fuel tank

Leaks in fuel system

Slow starter speed

Heavy engine oil

Wrong fuel

Water, dirt, or air in fuel system

Plugged fuel filter

Injectors

ENGINE RUNS
IRREGULARLY OR STALLS FREQUENTLY

Vent on fuel tank neck

Thermostat

Fuel filter

Water, dirt, or air in fuel system

Injectors

Wrong fuel

Air cleaner

ENGINE KNOCKS

Engine oil level

Injection pump timing

Coolant temperature (thermostat)

Engine overheating

Idle speed

ENGINE HAS LITTLE POWER

Engine overload

Air cleaner

Air cleaner intake hose

Fuel filter

Wrong fuel

Engine overheating

Low coolant temperature (thermostat)

Valve clearance

Injectors

Injection pump timing

LOW OIL PRESSURE

Engine oil level

Oil filter

Wrong oil

Oil leaks

ENGINE USES TOO MUCH OIL

Wrong engine oil

Engine drain plug

Air cleaner

IF

CHECK

ENGINE OVERHEATS

Engine Overload

Coolant level

Radiator cap

Oil filter

Thermostat

Alternator belt

Radiator

Water temperature indicator or sender

EXHAUST SMOKE
IS WHITE

Wrong fuel

Thermostat

Cold engine

Injectors

Injection pump timing

Low compression

EXHAUST IS GRAY
OR BLACK

Wrong fuel

Air intake or exhaust system

Engine overloaded

Injection nozzles

Injection pump timing

IF

CHECK

ENGINE USES TOO MUCH FUEL

Wrong fuel

Air cleaner

Engine overload

Valve clearance

Injection nozzles

Injection pump timing

Low engine temperature

Fuel leaks

Crankcase vent tube

IF

CHECK

ENTIRE ELECTRICAL SYSTEM DOES NOT WORK

Water soaked connections

Fusible link

Fuse

Loose or corroded connections

Battery

BATTERY WILL NOT TAKE A CHARGE

Loose or corroded connections

Battery

Belt

IF

CHECK

STARTER DOES
NOT WORK

Loose or corroded connections

Battery

Starter

STARTER CRANKS SLOWLY

Battery

Heavy engine oil

Loose or corroded connections

DEAD BATTERY

Solenoid

Ammeter light

Ignition switch

Battery

ALTERNATOR LIGHT GOES OUT WHEN ENGINE IS RUNNING

Engine speed

Alternator belt

Battery

Alternator

Grounded wire in circuit

IF

Check

SLOW HYDRAULIC FUNCTION

Oil level

Oil filter

Wrong oil

Pump

Relief valve

NOISY PUMP

Oil level

Wrong oil

Oil filters

Suction screen

Air leaks (fittings and parts)

OIL OVERHEATS

Oil level

Oil filters

High pressure internal leak

Dirty oil

Wrong oil

Brakes engaged

FOAMING OIL

Oil level

Wrong oil

Air leaks (fitting and parts)

IF

CHECK

BRAKES DO NOT HOLD

Loose or unadjusted linkage

BRAKES DO NOT WORK

Linkage adjustment

Worn wet disks

Damaged cam

Damaged wet disk spline

Damage final pinion

BRAKES NOISY

Correct oil

Water in oil

BRAKES DRAG

Linkage adjustment

Damaged return spring

IF

Check

MACHINE WILL NOT MOVE FORWARD OR BACKWARD

Low oil level

Wrong oil

Control linkage adjustment

Drive coupling

Charge pressure

Internal pump damage

NOISY SYSTEM

Low oil level

Air in system (fittings and parts)

Oil filter

Internal pump or motor

ACCELERATES SLOWLY

Low oil level

Loose or unadjusted control linkage

Air in system (fittings or parts)

Low charge pressure

Internal pump or motor

Brakes engaged

IF

CHECK

LOW OIL LEVEL. (EXCESSIVE OIL LEAKAGE)

Wrong oil

Damaged or missing gasket

Leaking oil seals

drain plug

Loose cove or housing cap screw

Hydraulic system leak

SPEED RANGE GEARS WILL NOT ENGAGE, HARD TO SHIFT, OR EXCESSIVE GEAR CLASH

Shifting too fast

Shifting with unit in motion

shift detents, worn or broken

Bent, worn or broken fork

Damaged gears

Incorrectly assembled gears

Damaged sliding gear or shaft splines

WILL NOT STAY
IN GEAR

Quadrant Adjustment

Missing shifter detent or weak spring

Damaged gears or bearings

Bent or worn shifter fork

PUMP DRIVE WILL NOT OPERATE. (INCLUDE PUMP DRIVE CLUTCH)

Low system pressure

Modulated relief valve

Pump

Low oil level

Oil strainer

Pump drive spool

O-rings

Worn or damaged disk

Worn or damaged shaft or spline

Stuck flow divider spool stuck

Worn or damaged seal ring

PUMP DRIVE WILL NOT STAY ENGAGED

Worn or damaged pump drive interlock linkage

Damaged gear or collar

DIFFERENTIAL DOES NOT WORK

Engaged lock slider

Worn or damaged pinion shaft

Bent or damaged locked shift fork

Damaged pinions or gears

Distorted housing

IF

CHECK

NO PUMP OUTPUT

PTO engaging

Hydraulic oil

Broken drive pump

Broken drive shaft

Broken pump spline

PUMP SHAFT SPLINE CONNECTOR ON PUMP HOUSING
BROKEN

Too high pressure relief setting

Auxiliary control valve failure

PUMP NOISE

Air drawn in the pump (cavitation)

Clogged intake strainer

Oil viscosity

Misaligned, worn, or broken pump drive casing

Loosen or distorted pump casing

OTHER NOISE

Relief valves. Do not operate over relief setting.

IF

CHECK

HYDRAULIC LIFT CANNOT BE LIFTED

Oil in axle housing

Pump pressure and flow

Oil strainer

Worn or broken pump drive coupling

Bolt specifications of control valve

Mechanical check valve

Control valve spool

Damaged relief valve spring

Dirt in relief valve and safety valve

Seized piston

Actuation of link mechanism

Stop valve

HYDRAULIC LIFT WON'T LIFT OR LIFT SPEED SLOW

Mechanical interference of linkages

Stuck priority flow divider spool

Contact surfaces of seats in relief valve and safety valve

Worn or broken relief valve springs and safety valve

Specification of relief valve pressure control

HYDRAULIC LIFT WON'T LIFT OR LIFT SPEED SLOW
(CONTINUED)

Clearance of gear and gear case of hydraulic pump

Broken hydraulic pump O-ring

Stuck proportional flow divider spool

Cavitation in low temperature

Intake strainer

Worn control valve

Damaged cylinder and cylinder case

LIFT ARM DROPS

Wear of spool and other parts of control valve

Seats of check valve and hold valve of control valve

Mechanical check valve

Seat of safety valve

O-ring seals

Damage to cylinder case

HYDRAULIC LIFT
CANNOT BE
LOWERED

Actuation of link mechanism in control valve

Failure of spool and hold valve of the control valve

Broken or worn return spring

IF

CHECK

HYDRAULIC LIFT CAN NOT BE LOWERED (CONTINUED)

Seized piston

Closed slow-return valve

Closed stop valve

Seized mechanical check valve

IF

CHECK

POOR CUTTING

Reel -to-bed knife adjustment

Dull reel and/or bed knife

Tall grass

Ground speed too high engine speed too slow

Cutting units not floating

Cutting units not following ground contour

Adjustment of weight transfer system

Backlap or grind of reel

IF

CHECK

CORRUGATED OR RIBBED APPEARANCE TO TURF
(MARCELLED)

Ground speed too high or engine rpm too slow

Too few reel blades

GRASS BUILDUP ON ROLLERS

Need for roller scrapers

UNITS WILL NOT LIFT HYDRAULICALLY

Low hydraulic pressure

Liquid mercury switch on outside of units

Hydraulic oil in reservoir

Cylinder seals

Lift and lower rates with drop-lock valve

Micro switch

Toggle switch for outside units

SOME REELS OR ALL REELS RUNNING BACKWARDS

Adjustable reel motor hydraulic valves

MOWER REELS SQUEAL

Operating without grass (juice lubricates reel and bed knife)

Reel-to-bed knife adjustment

BACKLAPPING REELS

Reels turning at high rpm

Reel engage toggle switch

IF

CHECK

REELS WILL NOT RUN OR RUN AT REDUCED RPM

Adjustable reel motor hydraulic valves turned clockwise (inward) to backlapping position

Reel motors on correct side

Micro switch

Reel motor hose connected right

Electrohydraulic valves

Relief valves

Flow divider

Switch to normal position

DRIVE GEAR AND DRIVEN GEAR WEAR PREMATURELY

Drive gear centered on shaft or driven gear; or drive gear and driven gear meshing too tight

OIL LEAKS FROM
CUTTING UNIT GEAR CASE

Crushed rubber hoses, metal pipe, or kinked elbows restricting oil flow on return or leak off lines

Drain lines between motors and manifold.

PTO WILL NOT
OPERATE WITHOUT OPERATOR IN SEAT FOR BACKLAPPING

Switch under seat not pulled up