Accessing the Evaporator in the John Deere 35G: A Step-by-Step Guide

[MikePhua]

When it comes to the maintenance and repair of heavy machinery, one of the common challenges operators and technicians face is accessing hard-to-reach components. In the case of the John Deere 35G mini excavator, the evaporator, which is a crucial part of the HVAC (heating, ventilation, and air conditioning) system, can be difficult to access due to its location within the cab. In this article, we will walk you through the process of accessing the evaporator, troubleshoot common issues, and provide maintenance tips to keep the system in optimal condition.
Understanding the Evaporator in the John Deere 35G
The evaporator in an HVAC system is responsible for cooling the air inside the cab. It works by absorbing heat from the air inside the cab and releasing it outside through the condenser. If your John Deere 35G is experiencing issues such as insufficient cooling or no air conditioning, the evaporator could be clogged, leaking, or malfunctioning in some way. Proper access to this component is essential for performing diagnostic checks, repairs, or replacement.
Why Accessing the Evaporator Can Be Challenging
The evaporator in the John Deere 35G is located in a tight area within the machine, typically behind the cabin or inside the HVAC housing. This placement is designed to protect the system from dust, debris, and exposure to the elements, but it can also make it difficult to get a good look or reach the evaporator for repairs or maintenance.
The first hurdle to overcome when accessing the evaporator is removing the various panels, seats, and other components that may be in the way. These steps require careful disassembly to avoid damaging other parts of the cab.
Step-by-Step Process to Access the Evaporator
Step 1: Preparation
Before beginning the disassembly process, ensure that the machine is powered off and has been properly secured. Disconnect the battery to avoid any accidental electrical issues during the procedure.

• Wear safety gloves and goggles to protect yourself from any sharp edges or debris that may be present inside the cab.
  
• Have a set of basic hand tools ready, including screwdrivers, wrenches, and a flashlight to help you see into the tight spaces.
  

Step 2: Remove the Seat and Floor Panels
The first components that need to be removed are the seat and the floor panels. These panels can obstruct access to the HVAC system and the evaporator.

• Seat removal: Unbolt the seat from its base. The John Deere 35G seat is typically secured by four bolts that need to be removed before the seat can be lifted out of place.
  
• Floor panels: Use a wrench or screwdriver to remove the screws or bolts holding the floor panel in place. Once the fasteners are removed, carefully lift the panel to expose the underlying HVAC housing.
  

Step 3: Remove the HVAC Housing or Cover
With the seat and floor panels removed, the next step is to access the HVAC housing. This is the compartment that houses both the evaporator and the condenser components.

• Depending on the design of the John Deere 35G, you may need to remove additional panels or trim around the HVAC system. This will typically involve unscrewing several bolts or clips that secure the housing in place.
  
• Take care when removing these parts as they may be fragile or prone to breaking if forced. A gentle approach will minimize the risk of damage.
  

Step 4: Locate the Evaporator
Once the HVAC housing is removed, you will be able to see the evaporator inside. It is usually situated toward the back of the system, often just behind the air ducts.

• The evaporator is a coil-shaped component, typically made of aluminum or copper, and may be partially covered by insulation or other protective layers.
  
• Check for any signs of damage or wear, such as coolant leaks, corrosion, or clogging, which could indicate the need for repairs or replacement.
  

Step 5: Inspect and Clean the Evaporator
If the evaporator appears to be clogged or dirty, it may be preventing proper airflow or cooling. This can happen over time as dust, debris, or even mold builds up on the coils. To clean the evaporator:

• Use compressed air: Blow air through the coils to dislodge dirt and debris.
  
• Vacuum: A vacuum with a brush attachment can help remove additional dirt and dust that may have accumulated in the coils or other areas.
  
• Coil cleaner: If the evaporator is particularly dirty or has mold growth, use a non-toxic coil cleaner specifically designed for HVAC systems. Follow the manufacturer’s instructions for safe application.
  

Step 6: Check for Leaks
If the HVAC system is still not cooling properly, you may need to inspect the evaporator for any leaks. A refrigerant leak can reduce the system’s efficiency and cause inadequate cooling.

• Use a refrigerant leak detection kit or UV dye to identify any leaks in the evaporator or connected lines.
  
• If a leak is found, you will need to replace the damaged component or repair the refrigerant lines.
  

Step 7: Reassemble the Components
Once the evaporator has been inspected, cleaned, or replaced, it’s time to reassemble the HVAC system.

• Reinstall the evaporator into its housing, ensuring it is securely fastened.
  
• Reattach any ducts or hoses that connect to the evaporator.
  
• Replace the HVAC housing and secure all panels back in place, including the floor panel and seat.
  

Common Issues with the Evaporator in the John Deere 35G
While accessing the evaporator is the first step toward resolving HVAC issues, there are some common problems that owners should be aware of:
1. Clogged Evaporator Coils
Over time, the evaporator coils can become clogged with dirt, dust, or debris. This blocks airflow and reduces the system’s cooling efficiency. Regular cleaning is crucial to prevent this problem.
2. Refrigerant Leaks
Refrigerant leaks are one of the most common causes of poor cooling performance. Leaks can occur in the evaporator itself or the connected refrigerant lines. Detecting and repairing these leaks is essential to restore proper cooling.
3. Electrical Issues
The HVAC system in the John Deere 35G relies on electrical components to control the blower fan and compressor. A malfunctioning switch, relay, or wiring issue can prevent the system from working correctly.
Preventative Maintenance Tips
To keep the evaporator and HVAC system in optimal condition, consider the following preventative maintenance tips:

1. Regular Cleaning: Clean the evaporator coils regularly to remove dust and debris that can cause blockages. This can be done during routine maintenance or whenever you notice a decrease in air conditioning performance.
   
2. Check Refrigerant Levels: Monitor refrigerant levels to ensure that the system is properly charged. Low refrigerant can cause inadequate cooling and can lead to damage over time.
   
3. Inspect the Cabin Air Filter: A clogged cabin air filter can affect airflow to the evaporator. Replace the air filter regularly to ensure efficient airflow and proper system function.
   
4. Leak Detection: If you notice a reduction in cooling performance, perform a leak check to ensure the refrigerant system is intact. Catching leaks early can save you from costly repairs later.
   

Conclusion
Accessing the evaporator in the John Deere 35G may seem like a complex task, but with proper steps and careful handling, it can be accomplished efficiently. By regularly inspecting, cleaning, and maintaining the HVAC system, operators can ensure that the air conditioning remains effective and that the cab stays cool and comfortable. If you experience persistent issues with your HVAC system, it may be time to seek professional assistance to ensure the system is functioning properly.