How to Change a 1990 Lexington RV Radiator
Changing a 1990 Lexington RV radiator is a crucial maintenance task that ensures your motorhome’s engine stays cool and prevents costly overheating issues. This process, while requiring some mechanical know-how and the right tools, is achievable for many DIY enthusiasts looking to save on labor costs and keep their vintage RV running smoothly. This guide will walk you through each step, from preparation to the final checks, making the radiator replacement process manageable and successful.
Simply put, replacing the radiator on a 1990 Lexington RV involves draining the old coolant, disconnecting hoses and the old radiator, installing the new one, refilling with coolant, and bleeding the system to remove air. Proper preparation and careful execution are key to avoiding leaks and ensuring optimal cooling performance for your vintage motorhome.
Key Takeaways
- Changing a 1990 Lexington RV radiator requires draining the cooling system, carefully removing the old unit, installing the new radiator, and properly refilling and bleeding the system.
- Gathering the correct tools and parts, including a new radiator, coolant, hoses, and basic mechanic’s tools, is essential before starting the job.
- Thoroughly flushing the cooling system before refilling can help remove debris and ensure the new radiator performs optimally.
- Bleeding the system is a critical step to remove air pockets, which can cause overheating even with a new radiator.
- Always dispose of old coolant responsibly and follow safety precautions throughout the process.
What is an RV Radiator and Why it Matters
The radiator in your 1990 Lexington RV serves the vital function of dissipating heat generated by the engine. As the engine runs, it produces a tremendous amount of heat. Coolant circulates through the engine block, absorbing this heat.
This heated coolant then flows to the radiator, where it passes through a series of fins and tubes. Air flowing through these fins, either from the vehicle’s movement or a dedicated fan, cools the coolant before it cycles back into the engine.
For a vehicle as large and often working under demanding conditions as an RV, a properly functioning radiator is non-negotiable. Overheating can lead to severe engine damage, including warped cylinder heads, blown head gaskets, and complete engine failure. For a 1990 model like the Lexington, maintaining this component is even more critical, as older cooling systems may be more prone to corrosion and wear.
Understanding the role of your radiator means appreciating the importance of regular maintenance. This includes checking coolant levels, inspecting hoses for cracks or leaks, and occasionally flushing the system to prevent buildup that can impede its efficiency. A compromised radiator can turn a dream road trip into a roadside emergency, making proactive maintenance your best strategy.
Components of the Cooling System
- Radiator: The primary heat exchanger.
- Coolant (Antifreeze): A mixture of water and ethylene glycol that absorbs and transfers heat.
- Thermostat: Regulates coolant flow to maintain optimal engine temperature.
- Water Pump: Circulates the coolant through the engine and radiator.
- Hoses: Connect the radiator, engine, and heater core, allowing coolant to flow.
- Radiator Cap: Maintains pressure within the cooling system.
- Cooling Fan: Pulls air through the radiator, especially at low speeds or idle.
- Heater Core: Transfers engine heat to the RV’s cabin for heating.
Signs of a Failing Radiator
Recognizing the signs of a failing radiator can save your engine. Keep an eye out for:
- Overheating: The most obvious sign is the temperature gauge rising into the red.
- Leaking Coolant: Puddles of green, pink, or orange fluid under your RV.
- Discolored Coolant: Rusty or murky coolant indicates internal corrosion.
- Visible Damage: Bent fins or cracks on the radiator itself.
- Sweet Smell: A sweet odor can indicate a coolant leak, often from the radiator or hoses.
What You’ll Need: Tools and Parts for the Job
Before you begin changing the radiator, ensure you have all the necessary tools and replacement parts readily available. This preparation minimizes downtime and prevents frustrating interruptions during the process. For a 1990 Lexington RV, the specific parts might vary slightly depending on the exact engine and chassis configuration, so always double-check compatibility with your vehicle’s VIN.
Having the right tools makes the job significantly easier and safer. Common automotive tools will suffice, but having specialized tools like a hose clamp plier set can be a real lifesaver. Remember to work in a well-ventilated area and wear appropriate safety gear, including gloves and eye protection, as coolant can be harmful.
Essential Tools
- Socket wrench set (metric and standard sizes)
- Pliers (including hose clamp pliers)
- Screwdrivers (Phillips and flathead)
- Drain pan (large enough for at least 5-6 gallons of coolant)
- Funnel
- Bucket
- Shop rags and paper towels
- Work gloves
- Safety glasses
- Torque wrench
- Garden hose or pressure washer (for cleaning)
- Jack and jack stands (if necessary for access)
Replacement Parts
- New Radiator: Ensure it’s specifically for a 1990 Lexington RV with your engine type.
- Coolant: The correct type and amount for your RV (check owner’s manual for capacity).
- New Radiator Hoses: Upper and lower hoses.
- Hose Clamps: It’s often best to replace old clamps with new ones.
- Thermostat and Gasket: Recommended to replace while the system is drained.
- Gallon jugs for old coolant disposal.
| Part | Why Replace | Notes |
|---|---|---|
| Radiator | Core leaks, internal corrosion, bent fins, reduced cooling efficiency. | Match vehicle specs precisely. |
| Radiator Hoses (Upper & Lower) | Cracks, swelling, hardness, leaks. Deterioration can lead to sudden hose failure. | Always replace both when replacing the radiator. |
| Thermostat & Gasket | Can fail to open or close properly, causing overheating or under-heating. | Cheap insurance for proper engine temp. |
| Hose Clamps | Corrosion, rust, or stripped threads can prevent a secure seal. | Use new, quality clamps for a reliable seal. |
Replacing critical components like hoses and the thermostat while the radiator is out is a wise practice to ensure the entire cooling system is in top shape. This proactive approach prevents future issues and ensures the longevity of your new radiator installation.
Step-by-Step: How to Change Your RV Radiator
Changing the radiator on your 1990 Lexington RV is a multi-step process that requires patience and attention to detail. Follow these steps carefully to ensure a successful replacement and a properly functioning cooling system.
Step 1: Drain the Old Coolant
Begin by locating the radiator drain plug, usually at the bottom of the radiator tank, or a lower radiator hose. Place your drain pan underneath. Open the drain plug or loosen the clamp on the lower radiator hose and allow all the old coolant to drain into the pan.
This process can take several minutes. If your RV has a separate expansion tank, drain that as well. Once drained, securely close the drain plug or reattach the hose.
Safety Note: Never drain coolant onto the ground. Collect it in a suitable container for proper disposal. Coolant is toxic to pets and wildlife and harmful to the environment.
Important: Ensure the engine is cool before starting this step. Working with hot coolant can cause severe burns.
Step 2: Remove the Old Radiator
Once the coolant is drained, disconnect the upper and lower radiator hoses from the radiator. Use pliers to loosen the hose clamps and twist or pull the hoses off. Be prepared for a small amount of residual coolant to spill.
Next, disconnect any transmission cooler lines if your radiator has integrated transmission fluid cooler lines. Carefully cap these lines to prevent dirt entry. Then, unbolt the radiator from its mounting brackets and release the fan shroud if it’s attached to the radiator.
Gently lift the old radiator out of the engine bay. This may require some maneuvering, especially if space is tight.
Step 3: Clean the Radiator Area
With the old radiator removed, take this opportunity to clean the area where the new radiator will sit. Use a hose to wash away any debris, leaves, or dirt that may have accumulated. Inspect the radiator support structure for any signs of rust or damage and address it if necessary.
Ensure the mounting points are clean and free of corrosion so the new radiator can be secured properly.
A clean environment also helps prevent debris from entering the new radiator’s fins and hindering its performance. You can use a soft brush or compressed air to clear out any stubborn buildup. This cleaning step is crucial for ensuring the new radiator has optimal airflow and is securely mounted.
Step 4: Install the New Radiator
Carefully place the new radiator into position, aligning it with the mounting brackets. Reinstall the fan shroud, ensuring it’s properly seated. Secure the radiator by bolting it into place, but do not overtighten the bolts initially.
Reconnect the transmission cooler lines if applicable, ensuring a secure connection.
Once the radiator is in place and loosely secured, you can then snug up the mounting bolts. Then, reconnect the upper and lower radiator hoses, ensuring the new hose clamps are positioned correctly and tightened firmly. Make sure the hoses are not rubbing against any engine components that could cause wear.
Step 5: Refill the Cooling System
Using a funnel, slowly fill the radiator with the recommended type and mixture of coolant. Fill it until you see the coolant level rise. Once the radiator is full, fill the expansion tank (if present) to the appropriate level.
Refer to your RV’s owner’s manual for the exact coolant capacity and mixture ratio (typically 50/50 coolant and distilled water).
It’s crucial to use distilled water, as tap water can contain minerals that can cause corrosion and clog the cooling system over time. Pouring slowly helps prevent air bubbles from getting trapped. Ensure you have enough coolant on hand, as larger RVs can hold a significant amount.
Step 6: Bleed the Cooling System
This is a critical step to remove any trapped air. Start the RV’s engine and let it run. Open the radiator bleeder screw (if equipped) or slightly loosen the radiator cap to allow air to escape.
As the engine heats up, the thermostat will open, allowing coolant to circulate. Continue to run the engine with the heater set to high to circulate coolant through the heater core. You may need to add more coolant as the air is purged.
Once no more air bubbles are seen and the coolant level remains stable, close the bleeder screw or tighten the radiator cap.
Tip: Some RVs have bleeder screws located on the engine block or heater hoses. Consult your service manual if you are unsure of their location. Monitor the temperature gauge closely during this process.
Step 7: Check for Leaks and Final Inspection
With the engine running and the cooling system bled, carefully inspect all connections for any signs of leaks. Check the radiator itself, the hoses, clamps, and any transmission cooler lines. Look for dripping coolant or any signs of moisture.
Once you’ve confirmed there are no leaks, let the engine cool down completely, then recheck the coolant level in the radiator and expansion tank. Top off if necessary. Take your RV for a short test drive, keeping a close eye on the temperature gauge to ensure it stays within the normal operating range.
Common Mistakes to Avoid
When undertaking a radiator replacement on your 1990 Lexington RV, several common pitfalls can lead to complications or premature system failure. Being aware of these mistakes can help you avoid them and ensure a successful repair.
One of the most frequent errors is not using the correct type or mixture of coolant. Using straight water or the wrong type of antifreeze can lead to corrosion, freezing, or boiling issues. Always adhere to the manufacturer’s recommendations found in your RV’s owner’s manual.
Common Errors and How to Prevent Them
- Not Draining All Coolant: Leaving old coolant in the system can dilute the new coolant and introduce contaminants. Always drain as much as possible.
- Reusing Old Hoses or Clamps: Even if they look okay, old rubber parts can fail unexpectedly. It’s best practice to replace hoses and clamps with the radiator.
- Over-Tightening or Under-Tightening Hose Clamps: Over-tightening can damage hoses, while under-tightening will lead to leaks. Aim for snug but not crushing tightness.
- Not Bleeding the System Properly: Air pockets are a major cause of overheating even with a new radiator. Ensure all air is purged.
- Using Tap Water: Minerals in tap water can cause scale buildup and corrosion in the cooling system. Always use distilled water.
- Ignoring Transmission Cooler Lines: If your radiator has integrated transmission cooler lines, failing to disconnect and reconnect them properly can lead to transmission fluid loss or contamination.
- Improper Coolant Disposal: Old coolant is toxic. Dispose of it at a local recycling center or auto shop that accepts hazardous waste.
Maintaining Your RV Cooling System After Replacement
After successfully changing your 1990 Lexington RV’s radiator, ongoing maintenance is key to ensuring its longevity and your RV’s reliability. A little preventive care goes a long way in avoiding future problems and keeping your engine running cool, especially on long journeys.
Regularly check your coolant levels. A quick visual inspection of the expansion tank each time you fuel up can alert you to potential leaks before they become major issues. Also, inspect hoses for any signs of cracking, swelling, or hardening.
Squeeze them gently; they should feel firm but pliable.
Regular Maintenance Schedule
- Check Coolant Level Weekly: Ensure the level in the expansion tank is between the ‘min’ and ‘max’ lines when the engine is cold.
- Inspect Hoses and Belts Monthly: Look for cracks, leaks, or signs of wear on all coolant hoses and the drive belts connected to the water pump.
- Flush and Refill Coolant Annually: Follow your RV’s service manual for the recommended coolant type and flush procedure. This removes debris and old coolant. According to the Coolant Manufacturers Association, a full system flush and refill every 1-2 years is recommended for optimal protection.
- Inspect Radiator Fins: Periodically check the radiator fins for damage or blockages from debris. Gently clean them with a soft brush or low-pressure water if needed.
- Test Thermostat: If you experience persistent temperature fluctuations, the thermostat might be faulty. A simple test involves placing it in hot water to see if it opens.
- Check Radiator Cap: Ensure the cap is sealing properly and the rubber gasket is in good condition. A faulty cap can lead to pressure loss and boiling.
Proper maintenance not only extends the life of your new radiator but also prevents the engine from overheating, which is critical for any RV, particularly older models like your 1990 Lexington. A well-maintained cooling system is essential for both performance and safety on the road. The U.S.
Department of Transportation estimates that vehicle breakdowns due to cooling system failures account for a significant percentage of roadside assistance calls annually.
Frequently Asked Questions
What is the typical lifespan of an RV radiator?
The lifespan of an RV radiator can vary significantly based on maintenance, driving conditions, and the quality of the original unit. However, a well-maintained radiator can typically last between 5 to 10 years, or roughly 50,000 to 100,000 miles.
How much coolant does a 1990 Lexington RV typically hold?
The coolant capacity for a 1990 Lexington RV can vary depending on the engine size and configuration. It’s essential to consult your RV’s owner’s manual for the exact capacity, but many Class A motorhomes can hold anywhere from 5 to 8 gallons or more of coolant mixture.
While universal radiators exist, it’s strongly recommended to use a radiator specifically designed for your 1990 Lexington RV model and engine. A direct-fit radiator ensures proper mounting, hose connections, and optimal cooling performance, preventing potential issues that can arise from ill-fitting universal parts.
How often should I flush my RV’s cooling system?
It’s generally recommended to flush and refill your RV’s cooling system at least once every one to two years, or according to the manufacturer’s service schedule. This process removes accumulated sediment, rust, and old coolant, ensuring the system operates efficiently and preventing potential corrosion.
What are the dangers of a leaking RV radiator?
A leaking RV radiator can lead to rapid engine overheating, which can cause severe and costly engine damage, including warped cylinder heads and blown head gaskets. Additionally, leaking coolant is toxic to animals and poses an environmental hazard if not properly contained and disposed of.
Final Thoughts
Successfully changing the radiator on your 1990 Lexington RV is a rewarding DIY project that ensures your vehicle’s reliability. By following these detailed steps, using the correct parts, and performing diligent maintenance, you can keep your engine running cool and enjoy many miles of worry-free travel. Remember, a well-maintained cooling system is fundamental to the health and longevity of your vintage motorhome.
