Kobalt VT6389 - User Manual

Questions and Answers

J
johnsonjeffreyAug 16, 2025
What to do if the reset mechanism cuts out repeatedly on my Kobalt VT6389?
- N
  Nicole WalkerAug 16, 2025
  If the reset mechanism of your Kobalt Air Compressor cuts out repeatedly, or the circuit breaker trips repeatedly, it could be due to several reasons. It may be caused by a lack of proper ventilation or a room temperature that is too high, in which case you should move the compressor to a well-ventilated area. Also, ensure that the circuit is limited to only the air compressor. Other potential causes include restricted air intake, loose electrical connections, or a pressure switch shut-off pressure set too high. Clean or replace the filter element, check all electrical connections, or replace the pressure switch.
V
vduncanAug 19, 2025
Why does the tank on my Kobalt Air Compressor not hold pressure?
- K
  klinedustinSep 12, 2025
  If your Kobalt Air Compressor tank does not hold pressure when the compressor is off and the shut-off valve is closed, it could be due to air leaks in the fittings or tubing. Check all connections with soap and water solution, then tighten or apply sealant to the threads before reassembling. It could also be caused by a worn check valve, in which case you should replace it. In addition, inspect the tank for cracks or pinholes, and replace the tank if any are found; never attempt to repair a damaged tank.
J
Jennifer HarrisAug 22, 2025
Why is the discharge pressure low on my Kobalt VT6389 Air Compressor?
- K
  katherine93Aug 22, 2025
  Low discharge pressure in your Kobalt Air Compressor can be caused by several factors. The air demand might exceed the pump capacity, in which case you should reduce the air demand or use a compressor with more capacity. A restricted air intake can also cause this issue, so clean or replace the air filter element. Air leaks in fittings or tubing can also lead to low pressure; listen for escaping air and apply a soap solution to identify leaks, then tighten or replace the leaking components. Blown gaskets or leaking/damaged valves can also be culprits; replace any faulty gaskets or defective valve parts.
L
Lindsay WestAug 25, 2025
How to fix excessive knocking noise in my Kobalt VT6389?
- T
  teresafosterAug 26, 2025
  Excessive noise (knocking) in your Kobalt Air Compressor can stem from several issues. Start by checking for loose components, such as a loose motor pulley or flywheel, and tighten the pulley/flywheel clamp bolts and set-screws. Also, check for loose fasteners on the pump or motor and tighten them. Lack of oil in the crankcase can also cause knocking, so check for the proper oil level and inspect for possible damage to bearings. Other causes include a worn connecting rod or piston pin bores, piston hitting the valve plate, or a noisy check valve in the compressor system. Replace the worn parts, maintain the oil level, and replace the check valve if needed.
B
Brian BrewerAug 28, 2025
What to do if the pressure switch on my Kobalt VT6389 Air Compressor continuously blows air out the unloader valve?
- G
  Glenda SnyderAug 28, 2025
  If your Kobalt Air Compressor's pressure switch continuously blows air out of the unloader valve, it is likely due to a malfunctioning check valve. Replace the check valve if the unloader valve on the pressure switch constantly bleeds off when the unit shuts off.
X
xlinAug 31, 2025
What to do if the pressure switch on my Kobalt VT6389 does not release air when the unit shuts off?
- T
  tcabreraAug 31, 2025
  If the pressure switch on your Kobalt Air Compressor does not release air when the unit shuts off, it is likely due to a malfunctioning unloader valve on the pressure switch. Replace the unloader valve if it does not release the pressure for a short period of time when the unit shuts off.
M
Mr. Vincent GonzalesSep 3, 2025
Why does my Kobalt VT6389 Air Compressor motor hum and run slowly or not at all?
- B
  brandon26Sep 3, 2025
  If your Kobalt Air Compressor motor hums and runs slowly or not at all, it could be due to several reasons. It could be due to low voltage, in which case you should check the incoming voltage (it should be approximately 230 volts). Avoid using an extension cord and ensure that the circuit is limited to the compressor only. Other potential causes include loose electrical connections, a malfunctioning pressure switch or check valve, a defective unloader valve or motor capacitor(s), or a defective motor. In such cases, you should replace the pressure switch, check valve, unloader valve, capacitor(s), or the motor.
A
Andrew HughesSep 5, 2025
How to reduce excessive vibration in my Kobalt VT6389 Air Compressor?
- J
  James HicksSep 6, 2025
  If your Kobalt Air Compressor is experiencing excessive vibration, it could be due to loose fasteners on the pump or motor, so tighten them. Another cause could be that the belt needs to be replaced, so replace it with the correct size. Finally, check the belt alignment and align the flywheel and pulley if necessary.
D
danielshahSep 9, 2025
Why is there a large quantity of oil in the discharge air from my Kobalt VT6389 Air Compressor?
- D
  Debra MorrisSep 9, 2025
  If you notice a large quantity of oil in the discharge air of your Kobalt Air Compressor, it could be due to worn piston rings. Replace them with new rings and maintain the oil level, changing the oil more frequently. Another cause could be a restricted compressor air intake, so clean or replace the filter and check for other restrictions in the intake system. Also, check for excessive oil in the compressor and drain it down to the full level. Finally, ensure you are using the correct oil viscosity, using Mobil 1® 10W-30 or full synthetic.
N
Nicholas OwenSep 12, 2025
Why is there water in the discharge air of my Kobalt VT6389?
- R
  Rachel SanchezSep 12, 2025
  Water in the discharge air or tank of your Kobalt Air Compressor is a normal part of operation, especially in humid weather. To address this, drain the tank more often, at least daily, and consider adding a filter to reduce the amount of water in the air line.

Summary

Product Specifications

Safety Guidelines and Hazard Symbols

Understanding Hazard Symbols

Explains hazard symbols like DANGER, WARNING, CAUTION, NOTICE.

General Safety Rules

Lists essential safety practices for operating the compressor.

Specific Safety Warnings and Warranty Disclaimer

Continued General Safety Practices

Covers safety points 6 through 15 for safe compressor operation.

Hazard-Specific Operational Warnings

Details risks of explosion, fire, injury, and equipment damage from specific situations.

Warranty Disclaimer Information

Outlines limitations and exclusions for product warranties.

Additional Safety Precautions and Operating Notices

Operational Safety Warnings

Covers belt guards, relief valves, operating pressure, and hot components.

Unit Care and Maintenance Notices

Highlights daily draining of the tank for maintenance.

Spraying Operation Safety

Provides precautions for spraying operations with the compressor.

Package Contents

Key Included Components

Details the pressure switch, safety valve, and discharge tube included in the package.

Package Contents and Hardware

Additional Compressor Parts

Lists parts D through K, including valves, gauges, filters, and regulators.

Included Hardware and Accessories

Details included hardware like nuts, washers, and rubber feet.

Preparation and Initial Assembly

Installation Requirements and Tools

Lists required tools and additional parts for assembly and use.

First Assembly Steps

Covers unbolting the unit from the skid and installing rubber feet.

Air Compressor Assembly Steps

Pump Cap Removal

Instructions for removing the pump cap before assembly.

Filter and Breather Installation

Guides on installing the air filter and breather components.

Lubrication and Oil Management

Oil Level Check Procedure

Instructions for checking and maintaining the correct oil level before operation.

Recommended Oils and Capacity

Lists suitable oil types and the required oil capacity for the compressor.

Electrical Safety and Requirements

Electrical Hazard Warnings

Details risks associated with shock, explosion, and property damage from electrical issues.

Voltage and Circuit Operation

Specifies conditions for operating the 120V, 15A unit on a standard circuit.

Grounding and Electrical Connections

Grounding Requirements for Safety

Explains the importance of grounding for electrical safety and shock prevention.

Voltage Compatibility and Outlets

Discusses operating on 120V or 240V circuits and proper outlet connections.

Start-Up and Break-In Procedure

Initial Operation Setup

Covers oil check, drain valve, and plugging in the unit.

Break-In Process and Timing

Details running the compressor at 0 psi for 30 minutes to break in pump parts.

Post Break-In Oil Change

Specifies the first oil change and subsequent maintenance schedule.

Recommended Operating Environment

Advises on ideal conditions for compressor operation.

Compressor Operation Modes and Moisture Control

Automatic Cycling Explained

Explains how the compressor automatically cycles on and off based on tank pressure.

Daily Tank Draining Procedure

Details the process for safely draining moisture from the tank daily.

Moisture Effects and Filtering

Discusses how moisture affects air quality and methods to reduce it.

Routine Care and Maintenance Tasks

Basic Cleaning and Checks

Outlines basic cleaning and checks for motor, tank, and filters.

Oil Change and Filter Maintenance

Provides step-by-step instructions for changing the compressor oil and checking the air filter.

Tank Draining and Air Filter Check

Details draining the tank and inspecting the air filter for cleanliness.

Advanced Maintenance and Troubleshooting Guide

Safety Valve and Belt Inspection

Instructions for testing the safety valve and checking belt condition.

Maintenance Schedule Summary

A table outlining daily, weekly, monthly, and quarterly maintenance tasks.

Troubleshooting Low Discharge Pressure

Identifies causes and solutions for low air pressure output.

Troubleshooting Common Operational Issues

Addressing Noise and Oil Contamination

Solutions for excessive noise, worn parts, and oil in air.

Correcting Low Pressure and Oil Issues

Diagnoses and fixes for low pressure, oil contamination, and worn components.

Troubleshooting Performance and Electrical Problems

Resolving Water and Motor Issues

Solutions for water in air, slow motor operation, and circuit tripping.

Addressing Circuit Breaker Trips

Diagnoses and fixes for repeated circuit breaker trips or reset mechanism cut-outs.

Troubleshooting Pressure and Vibration Issues

Pressure Switch and Tank Integrity

Solutions for pressure switch air bleeding and holding tank pressure.

Correcting Excessive Vibration Causes

Addresses causes of excessive vibration and their corrective actions.

Warranty Information and Coverage

Pressure Switch Function and Warranty Terms

Covers pressure switch air release and general warranty terms.

Warranty Coverage and Exclusions

Details what is covered and not covered under the product warranty.

Warranty Responsibilities and Service Procedures

Warranty Exclusions and Purchaser Duties

Lists additional exclusions and buyer's responsibilities for warranty claims.

Warrantor Duties and Repair Scheduling

Outlines the warrantor's duties and conditions for repair or replacement.

Replacement Parts Diagram

Replacement Parts List - Components

Key Unit Components

Lists essential parts like tank, valves, gauges, switches, and motor with part numbers.

Hardware and Small Parts List

Details screws, nuts, washers, and other smaller hardware items with part numbers.

Replacement Parts Visual Guide

Replacement Parts List - Additional Items

Motor and Pump Assembly Parts

Lists replacement parts for the electric motor, pump, and related assemblies.

Filter and Connector Replacements

Details replacement filters, connectors, nipples, and reducers.

Pump Assembly Components Diagram

Detailed Pump Component Replacement Parts

Internal Pump Part Numbers

Lists parts like crankcase, cylinder, piston, bearings, and valve plates with part numbers.

Replacement Parts Kits Availability

Identifies available kits, such as gasket kits, for replacement.

Notes and Printing Information

Summary

Product Specifications

Safety Guidelines and Hazard Symbols

Understanding Hazard Symbols

Explains hazard symbols like DANGER, WARNING, CAUTION, NOTICE.

General Safety Rules

Lists essential safety practices for operating the compressor.

Specific Safety Warnings and Warranty Disclaimer

Continued General Safety Practices

Covers safety points 6 through 15 for safe compressor operation.

Hazard-Specific Operational Warnings

Details risks of explosion, fire, injury, and equipment damage from specific situations.

Warranty Disclaimer Information

Outlines limitations and exclusions for product warranties.

Additional Safety Precautions and Operating Notices

Operational Safety Warnings

Covers belt guards, relief valves, operating pressure, and hot components.

Unit Care and Maintenance Notices

Highlights daily draining of the tank for maintenance.

Spraying Operation Safety

Provides precautions for spraying operations with the compressor.

Package Contents

Key Included Components

Details the pressure switch, safety valve, and discharge tube included in the package.

Package Contents and Hardware

Additional Compressor Parts

Lists parts D through K, including valves, gauges, filters, and regulators.

Included Hardware and Accessories

Details included hardware like nuts, washers, and rubber feet.

Preparation and Initial Assembly

Installation Requirements and Tools

Lists required tools and additional parts for assembly and use.

First Assembly Steps

Covers unbolting the unit from the skid and installing rubber feet.

Air Compressor Assembly Steps

Pump Cap Removal

Instructions for removing the pump cap before assembly.

Filter and Breather Installation

Guides on installing the air filter and breather components.

Lubrication and Oil Management

Oil Level Check Procedure

Instructions for checking and maintaining the correct oil level before operation.

Recommended Oils and Capacity

Lists suitable oil types and the required oil capacity for the compressor.

Electrical Safety and Requirements

Electrical Hazard Warnings

Details risks associated with shock, explosion, and property damage from electrical issues.

Voltage and Circuit Operation

Specifies conditions for operating the 120V, 15A unit on a standard circuit.

Grounding and Electrical Connections

Grounding Requirements for Safety

Explains the importance of grounding for electrical safety and shock prevention.

Voltage Compatibility and Outlets

Discusses operating on 120V or 240V circuits and proper outlet connections.

Start-Up and Break-In Procedure

Initial Operation Setup

Covers oil check, drain valve, and plugging in the unit.

Break-In Process and Timing

Details running the compressor at 0 psi for 30 minutes to break in pump parts.

Post Break-In Oil Change

Specifies the first oil change and subsequent maintenance schedule.

Recommended Operating Environment

Advises on ideal conditions for compressor operation.

Compressor Operation Modes and Moisture Control

Automatic Cycling Explained

Explains how the compressor automatically cycles on and off based on tank pressure.

Daily Tank Draining Procedure

Details the process for safely draining moisture from the tank daily.

Moisture Effects and Filtering

Discusses how moisture affects air quality and methods to reduce it.

Routine Care and Maintenance Tasks

Basic Cleaning and Checks

Outlines basic cleaning and checks for motor, tank, and filters.

Oil Change and Filter Maintenance

Provides step-by-step instructions for changing the compressor oil and checking the air filter.

Tank Draining and Air Filter Check

Details draining the tank and inspecting the air filter for cleanliness.

Advanced Maintenance and Troubleshooting Guide

Safety Valve and Belt Inspection

Instructions for testing the safety valve and checking belt condition.

Maintenance Schedule Summary

A table outlining daily, weekly, monthly, and quarterly maintenance tasks.

Troubleshooting Low Discharge Pressure

Identifies causes and solutions for low air pressure output.

Troubleshooting Common Operational Issues

Addressing Noise and Oil Contamination

Solutions for excessive noise, worn parts, and oil in air.

Correcting Low Pressure and Oil Issues

Diagnoses and fixes for low pressure, oil contamination, and worn components.

Troubleshooting Performance and Electrical Problems

Resolving Water and Motor Issues

Solutions for water in air, slow motor operation, and circuit tripping.

Addressing Circuit Breaker Trips

Diagnoses and fixes for repeated circuit breaker trips or reset mechanism cut-outs.

Troubleshooting Pressure and Vibration Issues

Pressure Switch and Tank Integrity

Solutions for pressure switch air bleeding and holding tank pressure.

Correcting Excessive Vibration Causes

Addresses causes of excessive vibration and their corrective actions.

Warranty Information and Coverage

Pressure Switch Function and Warranty Terms

Covers pressure switch air release and general warranty terms.

Warranty Coverage and Exclusions

Details what is covered and not covered under the product warranty.

Warranty Responsibilities and Service Procedures

Warranty Exclusions and Purchaser Duties

Lists additional exclusions and buyer's responsibilities for warranty claims.

Warrantor Duties and Repair Scheduling

Outlines the warrantor's duties and conditions for repair or replacement.

Replacement Parts Diagram

Replacement Parts List - Components

Key Unit Components

Lists essential parts like tank, valves, gauges, switches, and motor with part numbers.

Hardware and Small Parts List

Details screws, nuts, washers, and other smaller hardware items with part numbers.

Replacement Parts Visual Guide

Replacement Parts List - Additional Items

Motor and Pump Assembly Parts

Lists replacement parts for the electric motor, pump, and related assemblies.

Filter and Connector Replacements

Details replacement filters, connectors, nipples, and reducers.

Pump Assembly Components Diagram

Detailed Pump Component Replacement Parts

Internal Pump Part Numbers

Lists parts like crankcase, cylinder, piston, bearings, and valve plates with part numbers.

Replacement Parts Kits Availability

Identifies available kits, such as gasket kits, for replacement.

Notes and Printing Information

Kobalt VT6389 Specifications

General

Maximum Pressure	150 PSI
Pump Type	Oil-Free
Voltage	120V
Tank Size	6 gallons
SCFM at 90 PSI	2.6 SCFM

Related product manuals

Kobalt Air compressor

24 pages

Kobalt VT6389 - User Manual

Table of Contents

Questions and Answers

Summary

Product Specifications

Safety Guidelines and Hazard Symbols

Understanding Hazard Symbols

General Safety Rules

Specific Safety Warnings and Warranty Disclaimer

Continued General Safety Practices

Hazard-Specific Operational Warnings

Warranty Disclaimer Information

Additional Safety Precautions and Operating Notices

Operational Safety Warnings

Unit Care and Maintenance Notices

Spraying Operation Safety

Package Contents

Key Included Components

Package Contents and Hardware

Additional Compressor Parts

Included Hardware and Accessories

Preparation and Initial Assembly

Installation Requirements and Tools

First Assembly Steps

Air Compressor Assembly Steps

Pump Cap Removal

Filter and Breather Installation

Lubrication and Oil Management

Oil Level Check Procedure

Recommended Oils and Capacity

Electrical Safety and Requirements

Electrical Hazard Warnings

Voltage and Circuit Operation

Grounding and Electrical Connections

Grounding Requirements for Safety

Voltage Compatibility and Outlets

Start-Up and Break-In Procedure

Initial Operation Setup

Break-In Process and Timing

Post Break-In Oil Change

Recommended Operating Environment

Compressor Operation Modes and Moisture Control

Automatic Cycling Explained

Daily Tank Draining Procedure

Moisture Effects and Filtering

Routine Care and Maintenance Tasks

Basic Cleaning and Checks

Oil Change and Filter Maintenance

Tank Draining and Air Filter Check

Advanced Maintenance and Troubleshooting Guide

Safety Valve and Belt Inspection

Maintenance Schedule Summary

Troubleshooting Low Discharge Pressure

Troubleshooting Common Operational Issues

Addressing Noise and Oil Contamination

Correcting Low Pressure and Oil Issues

Troubleshooting Performance and Electrical Problems

Resolving Water and Motor Issues

Addressing Circuit Breaker Trips

Troubleshooting Pressure and Vibration Issues

Pressure Switch and Tank Integrity

Correcting Excessive Vibration Causes

Warranty Information and Coverage

Pressure Switch Function and Warranty Terms

Warranty Coverage and Exclusions

Warranty Responsibilities and Service Procedures

Warranty Exclusions and Purchaser Duties

Warrantor Duties and Repair Scheduling

Replacement Parts Diagram

Replacement Parts List - Components

Key Unit Components

Hardware and Small Parts List

Replacement Parts Visual Guide

Replacement Parts List - Additional Items

Motor and Pump Assembly Parts

Filter and Connector Replacements

Pump Assembly Components Diagram

Detailed Pump Component Replacement Parts

Internal Pump Part Numbers

Replacement Parts Kits Availability