Kubota ZD28 - User Manual

Questions and Answers

J
James ThompsonAug 20, 2025
What to do if Kubota ZD28 has low oil pressure?
- C
  Christopher KempAug 20, 2025
  If you're experiencing low oil pressure, you can replenish the engine oil, clean the oil strainer, change the engine oil filter cartridge, clean or replace the relief valve, replace the relief valve spring, replace the main bearings, metals, or crankshaft, replace the crankpin bearings, replace the rocker arms, rocker arm brackets, or rocker arm shaft, clean the oil passage, use the specified type of oil, or repair or replace the oil pump.
C
Crystal CarsonAug 23, 2025
What to do if Kubota ZD28 engine overheated?
- P
  Paul NorrisAug 23, 2025
  If your engine is overheating, try these solutions: Replenish engine oil, replace the fan belt or adjust the fan belt tension, replenish coolant, clean the radiator net and radiator fin, clean inside of radiator or replace radiator, clean or replace coolant flow route or replace the radiator cap. Also, loosen the load, replace the head gasket, adjust the injection timing, or use the specified fuel.
J
Jennifer GarrettAug 26, 2025
What to do if Kubota ZD28 has deficient output?
- J
  Jessica PriceAug 26, 2025
  If you notice deficient output, you can adjust the injection timing, repair or replace the engine’s moving parts, repair or replace the injection pump, repair or replace the nozzle, or replace the head gasket and tighten the cylinder head screws, glow plugs, and nozzle holders.
C
christine68Aug 28, 2025
What to do if Kubota Lawn Mower engine revolution is not smooth?
- M
  Matthew LaraAug 28, 2025
  If the engine revolution isn't smooth, try replacing the fuel filter, cleaning or replacing the air cleaner element, tightening the retaining nut, repairing or replacing the injection pump, adjusting the nozzle injection pressure, repairing or replacing the injection nozzle, or repairing the governor.
A
alvarezericAug 31, 2025
Why Kubota Lawn Mower has excessive lubricant oil consumption?
- B
  brookstimothyAug 31, 2025
  If there is excessive lubricant oil consumption, consider shifting the ring gap direction, replacing the oil ring, replacing the piston, replacing the valve and valve guide, or replacing defective seals or packing.
M
markrodriguezSep 2, 2025
What to do if Kubota Lawn Mower emits black or dark gray exhaust gas?
- M
  Michael BowenSep 2, 2025
  If you observe black or dark gray exhaust gas, you can lessen the load, use the specified fuel, replace the fuel filter, clean or replace the air cleaner element or repair or replace the nozzle.
G
Gina KeithSep 5, 2025
What to do if Kubota ZD28 has fuel mixed into lubricant oil?
- J
  Jeffrey DaySep 5, 2025
  If fuel is mixed into the lubricant oil, you can replace the pump element or injection pump, repair or replace the nozzle, or replace the injection pump.
C
Courtney SolisSep 8, 2025
What to do if Kubota ZD28 emits white or blue exhaust gas?
- A
  Anthony CastilloSep 8, 2025
  If you observe white or blue exhaust gas, you can reduce to the specified engine oil level, repair the piston ring and bore oversize piston, adjust the injection timing, or replace each bearings.
T
tcruzSep 12, 2025
What to do if Kubota Lawn Mower has high oil pressure?
- M
  Mark Martinez Jr.Sep 12, 2025
  If there is high oil pressure, you can use the specified type of oil or replace the relief valve.
M
Melinda BurnettSep 14, 2025
What to do if Kubota ZD28 Lawn Mower has water mixed into lubricant oil?
- E
  Erica GreeneSep 14, 2025
  If water is mixed into the lubricant oil, you can replace the head gasket or replace the cylinder block or cylinder head.

Summary

SAFETY INSTRUCTIONS

SAFETY FIRST

General safety symbol explanation and importance of reading instructions.

BEFORE SERVICING AND REPAIRING

Pre-servicing checklist including area cleanup and safety precautions.

SAFETY STARTING

Safety precautions for starting the engine and operating the machine.

SAFETY WORKING

Safety measures during work, including clothing and tool usage.

G GENERAL

4. LUBRICANTS, FUEL AND COOLANT

5. TIGHTENING TORQUES

Specified torque values for screws, bolts, and nuts.

6. MAINTENANCE CHECK LIST

Overview of scheduled maintenance intervals and items.

7. CHECK AND MAINTENANCE

Detailed procedures for routine checks and maintenance.

[1] DAILY CHECK

Essential checks to perform before each operation.

[2] CHECK POINTS OF INITIAL 50 HOURS

ENGINE

SERVICING

Procedures for servicing the engine and its components.

4. TIGHTENING TORQUES

Specified torque values for engine assembly fasteners.

5. CHECKING, DISASSEMBLING AND SERVICING

Detailed procedures for engine checks, disassembly, and assembly.

[2] ENGINE BODY

Procedures for checking and servicing engine body components.

[5] FUEL SYSTEM

TRANSAXLE

2. TRAVELLING SYSTEM

[1] HYDROSTATIC TRANSMISSION

Explanation of the hydrostatic transmission system.

(6) Power Trains Operation

4. CHECKING AND ADJUSTING

Procedures for checking and adjusting transaxle functions.

Adjusting Neutral

Adjusting Maximum Speed

5. DISASSEMBLING AND ASSEMBLING

Steps for disassembling and assembling the transaxle.

[1] SEPARATING TRANSAXLE

HYDRAULIC SYSTEM

1. HYDRAULIC CIRCUIT

3. HYDRAULIC CONTROL VALVE AND VALVE ADAPTOR

3. CHECKING, DISASSEMBLING AND SERVICING

Maintenance of hydraulic system components.

[1] HYDRAULIC CONTROL VALVE, PUMP AND CYLINDER

(1) Checking and Adjusting

Relief Valve Setting Pressure

ELECTRICAL SYSTEM

1. WIRING DIAGRAM

2. STARTING SYSTEM

Description of how the engine starts.

[1] STARTER

[3] SAFETY SWITCH (LIMIT SWITCH)

3. CHARGING SYSTEM

How the battery is charged and charging system components.

4. CHECKING, DISASSEMBLING AND SERVICING

Maintenance of electrical system components.

[1] BATTERY

(1) Checking

Battery Specific Gravity

[2] STARTING SYSTEM

Checks and servicing of the starting system components.

(A) Safety Switches

(B) Main Switch

(C) Starter

[3] CHARGING SYSTEM

Checks and servicing of the charging system components.

(1) Checking

Battery Charging Current

ROTARY MOWER

1. POWER TRANSMISSION

2. LIFTING MECHANISM

SERVICING

1. TROUBLESHOOTING

Diagnosing and resolving common mower issues.

4. CHECKING, DISASSEMBLING AND ASSEMBLING

Maintenance of mower components.

[1] CHECKING AND ADJUSTING

Adjusting Anti-scalp Rollers

Adjusting Left and Right Cutting Height

Adjusting Front and Rear Cutting Height

[2] DISASSEMBLING AND ASSEMBLING

Mower Blades (Center Blade and Outer Blades)

Disassembling Gear Box

Kubota ZD28 Specifications

General

Engine Type	Diesel
Horsepower	28 HP
Transmission	Hydrostatic
Cutting Width	60 inches
Type	Zero-turn mower
Cutting Height	1 - 5 inches
Engine Model	Kubota D1105
Displacement	68.5 cu in