RC Car Maintenance: The Complete Guide for Performance and Longevity

📋 Optimal cleaning procedure:

1. Preliminary cleaning (2 min): Use a soft brush or paintbrush to remove dirt and debris from the suspension arms, chassis, and wheels. A can of compressed air (or compressor) is ideal for removing dust from hard-to-reach areas such as the engine compartment and wheel bearings.
2. Fine cleaning (2 min): A slightly damp microfiber cloth is sufficient for the bodywork and plastic surfaces. For stubborn stains, a diluted multi-purpose cleaner (such as Muc-Off or Simple Green) is effective.
3. Drying (1 min): Wipe the metal parts with a dry cloth to prevent corrosion, even on "waterproof" models.

🚫 Absolutely Avoid: High-pressure water jets (like Kärcher)! They can penetrate electronics (even those certified "waterproof"), bearings, and motors, causing oxidation, corrosion, and premature failure. Pressurized water puts stress on protective seals.

🔎 Critical checkpoints:

Area to be inspected	What to check	Frequency
Wheel screws	Tightening, hexagonal pins	Each exit
Suspension triangles	Cracks, dislodged ball joints	Each exit
Engine mount	Loose screws, abnormal vibrations	Each exit
Electrical cables	Pinching, stripping, excessive tension	Each exit
Bumper	Cracks, significant deformations	Every 2-3 outings

🔌 The 3 golden rules of Li-Po batteries:

1. Never store a fully charged battery: If you don't plan to ride within 48 hours , you must use the "Storage" function on your charger. This will bring each cell to an ideal storage voltage (~3.8V/cell), preventing swelling and premature chemical degradation.
2. Never store a completely discharged battery: A battery discharged below 3.0V/cell suffers irreversible damage. Always recharge after use or switch to Storage mode.
3. Systematic visual inspection: Before and after each charge, inspect the battery. Any swelling, deformation, or abnormal odor requires immediate disposal according to the safety procedure.

🛠️ Pinion and crown gear maintenance:

• Cleaning (every 5 outings): Remove the protective cover. Use a stiff brush (like a toothbrush) to clean between the teeth. Remove any embedded debris, grass, and mud that increases friction.
• Wear inspection: Check that no teeth are broken, chipped, or excessively worn (shark tooth profile). A worn pinion or chainring creates noise, vibration, and reduced efficiency.
• Checking the gap: The clearance between the pinion and crown gear should allow a sheet of paper to pass through. Too tight = rapid wear and overheating. Too loose = noise and skipping teeth.
• Lubrication: Apply a drop of silicone gear grease (not liquid oil which will splatter everywhere). Rotate manually to distribute.

🔩 Differential maintenance (every 6 months):

Differentials allow the left and right wheels to rotate at different speeds when cornering. The oil they contain degrades over time.

• Disassembly: Remove the screws from the differential housing (be careful not to lose the small satellite gears inside)
• Complete cleaning: Drain the old, blackened oil, clean all the gears with degreaser.
• Refilling: Use new silicone oil suitable for your application:
  - 3000-5000 WT: All-terrain, maximum grip, responsiveness
  - 5000-10000 WT: Track, compromise between grip and speed
  - 10000+ WT: Road race, maximum top speed

🧪 Bearing performance test:

1. Free rotation test: Lift the car, give each wheel a sharp spin by hand. It should rotate for at least 5-7 seconds without any grinding noise or stiff spots.
2. Hearing test: Slowly rotate each wheel near your ear. No rolling, squeaking, or rumbling noise should be audible.
3. If a fault is detected: Identify the defective bearing (wheel, drive shaft, shock absorber spindle) and proceed with cleaning or replacement.

🧼 Procedure for cleaning a seized bearing:

1. Remove the bearing from its housing
2. Carefully remove the protective covers (be careful, they may pop off!)
3. Immerse the bearing in a degreasing bath (white spirit, white spirit, brake cleaner).
4. Shake and brush to remove all traces of dirt
5. Rinse with isopropyl alcohol and dry with compressed air
6. Apply a single drop of bearing oil (such as WD-40 Specialist or Bones Speed ​​Cream)
7. Reattach the flanges and reinstall.

💡 Tip: If a bearing is too damaged (pitted balls, deformed cage), replace it. A complete set of bearings costs €15-30 and literally transforms performance.

🔍 Diagnosis of faulty shock absorbers:

• Leak detection: Inspect the body of each shock absorber. A trace of oil seeping out = worn seal = immediate replacement required.
• Rebound test: Press down firmly on the car and release. It should return to its original position in 1-2 bounces maximum . More bounces indicate degraded oil or the presence of air bubbles.
• Compression test: Manually compress each shock absorber. The resistance should be smooth, constant, without any hard spots or soft areas.

🔧 Shock absorber filling procedure:

1. Complete disassembly: Remove the shock absorbers from the chassis, then disassemble them (body, rod, springs)
2. Cleaning: Drain the old oil, clean the inside of the body with isopropyl alcohol.
3. Bubble-free filling: Slowly pour in fresh silicone oil (viscosity suited to your practice), gently push the rod in to expel any air, repeat until all bubbles are gone
4. Viscosity selection:
   - 200-300 WT: Soft suspension, rough terrain, big jumps
   - 300-400 WT: Versatile, good compromise between comfort and responsiveness
   - 400-500+ WT: Firm suspension, smooth track, race
5. Reassembly and final bleeding: Reassemble, compress several times, and check for leaks.

⚙️ Brushless motor (no major maintenance)

These brushless motors are virtually indestructible if used correctly. Maintenance is minimal:

• External cleaning (every 5 runs): Use compressed air to remove dust from the cooling fins. Accumulated dust reduces thermal efficiency and causes overheating.
• Checking the fixings: Check that the motor fixing screws are tight. Vibrations can gradually loosen them.
• Visual inspection: Look for any signs of overheating (discoloration, burning smell). An engine that overheats (>85°C) indicates a problem with the ventilation, an unsuitable gear ratio, or an undersized ESC.

📖 To learn more: Read our complete guide on brushless motors to understand how they work, the different KV ratings and how to optimize their performance.

🔌 Brushed/Carbon Brushed Motor (regular maintenance required)

These traditional motors require more attention because the brushes (carbon brushes) wear out in contact with the commutator:

• Collector cleaning (every 10 rides): Remove the rear cover, spray an electronic contact cleaner spray on the collector (rotating copper part), let it work and wipe with a clean cloth.
• Checking the brushes (every 20-30 outings): Inspect the brushes for wear. If they measure less than 3mm, replace them (set of brushes: €5-10).
• Initial break-in: A new brushed motor requires break-in: 3-4 batteries while driving progressively (no prolonged full throttle) to form an optimal contact surface.

🖥️ ESCs and Electrical Connections

The electronic control unit (ESC) and its connections are the nervous system of your car:

• Connector inspection (every 5 outputs): Check that the plugs (XT60, Deans, EC3, Tamiya) are not damaged, oxidized, or loose. Poor contact creates resistance, heat, and power loss.
• Solder joint check: Inspect the cable solder points. A loose solder joint can cause random breaks.
• Contact cleaning: If oxidation occurs, clean gently with a contact cleaner or isopropyl alcohol.
• ESC thermal management: If your ESC is overheating (>70°C), add a heatsink or fan (10-20€). Overheating reduces lifespan and can cause thermal cut-outs.

🌬️ The Air Filter: The Engine's Lungs (REVIEW)

A clogged filter is the number one cause of premature death of RC internal combustion engines.

• After each ride: Remove the air filter and tap it to remove coarse dust.
• Cleaning (every 3-5 outings): Wash the filter with warm soapy water, rinse thoroughly, and let it dry completely (24 hours).
• Re-oiling is mandatory: Once dry, saturate the filter with special air filter oil (such as K&N or Mugen). This allows it to capture fine particles without choking the engine.
• Replacement: Every 6 months or if the filter is torn/deformed (cost: €5-15)

💧 "After-Run" Oil: Anti-Corrosion Protection (MANDATORY)

If you are not driving the next day, this step is MANDATORY to avoid internal corrosion.

Nitro fuel contains methanol, which attracts moisture. Without protection, the engine will rust from the inside out within days.

After-run procedure:

1. After the last outing, completely empty the tank
2. Start the engine and let it run until it stops on its own (residual fuel consumption)
3. Remove the glow plug
4. Put 3-5 drops of after-run oil into the spark plug hole AND into the carburetor intake
5. Pull the starter 5-6 times to distribute the oil over all internal surfaces
6. Replace the spark plug (without tightening it fully to avoid compression).

💰 Cost vs. Benefit: A bottle of after-run oil costs €8-12 and lasts a full season. A new combustion engine costs €80-200. The math is simple.

🔌 Glow Plug: Consumable Item

• Regular inspection (every 5 outings): Remove the candle and inspect the filament. It should be bright, silvery, undamaged, and slightly glowing when you light the candle warmer.
• Signs of failure: Filament deformed, broken, blackened, oxidized = immediate replacement (cost: €8-15)
• Spark plug selection: Spark plugs are classified by "heat range" (operating temperature). Consult your engine manual to choose the correct range based on the ambient temperature and the fuel used.
• Lifespan: A well-maintained spark plug lasts 10-20 hours of engine operation

🔧 Additional Specific Thermal Maintenance

• Cleaning the cooling fins: Remove dust with a soft brush to maintain optimal cooling
• Clutch system check: Check the wear of the linings and the play in the centrifugal weights.
• Launcher check: Check the condition of the string, the return spring, and the training cone.
• Fuel system flush: Every 3 months, completely drain the tank and fuel lines to prevent deposits.

Step 1: Cleaning and Thorough Inspection (30-45 min)

• Apply all the cleaning and deep maintenance steps described previously
• Carefully inspect each component, noting the parts that need replacing for the next step.
• Clean the metal parts particularly well to prevent corrosion during storage

Step 2: Battery Management (10 min) 🔋

• Li-Po batteries: Put ALL your batteries in "Storage" mode (3.8V/cell). NEVER leave them fully or empty for an extended period.
• Monthly check: Even in storage, check the voltage every 1-2 months. If a battery drops below 3.7V/cell, recharge it slightly and put it back in storage.
• Physical storage: Place the batteries in a Li-Po fireproof bag, in a cool (15-20°C), dry place, away from sunlight and heat sources.
• NiMH batteries: Store them at approximately 50% charge, recharge them every 2-3 months to avoid complete self-discharge.

Step 3: Mechanical Protection (5 min)

• Suspension unloading: Place the car on a support (wheel chocks, foam blocks) so that the tires are not touching the ground. This prevents tire deformation (flat spots) and constant compression of the shock absorber springs.
• Corrosion protection: Spray a lubricant/moisture repellent (WD-40, CRC 6-66) on all exposed metal parts (screws, axles, bearings, universal joints). Wipe off any excess.
• Cables and connectors: Disconnect all electrical connectors to prevent oxidation of the contacts. Wrap them in absorbent paper if the environment is humid.

Step 4: Choosing the Storage Location

The storage environment is crucial to preventing corrosion and degradation:

• ✅ Ideal: Heated and dry indoors (15-25°C), away from direct sunlight, in a box or under a dust cover
• ⚠️ Acceptable: Unheated but dry garage, protected from humidity and rodents
• 🚫 To avoid: Damp cellar, overheated attic in summer, garage open to the elements, proximity to corrosive chemicals

Step 5: Thermal Specifications (Nitro/Gasoline)

For internal combustion engines, the after-run procedure is MANDATORY:

• Completely empty the fuel tank and fuel lines
• Run the engine until all the remaining fuel is consumed.
• Apply the after-run oil generously (see thermal section)
• Remove the candle and add 2-3 more drops of after-run oil, then pull the launcher 10 times.
• Replace the spark plug (without tightening it fully), and protect the air filter in a plastic bag.

🔧 Mechanical Tools

• Set of hex (Allen) screwdrivers: 1.5, 2.0, 2.5, 3.0mm minimum
• Cross wrench for wheels (17mm standard)
• Needle-nose pliers and wire cutters
• Socket wrenches (if equipped)
• Circlip pliers (for bearings)

💰 Budget: €30-60

🧴 Cleaning & Lubrication

• Compressed air bomb
• Soft brushes (various sizes)
• Microfiber cloths (×3-5)
• Degreaser (Muc-Off, Simple Green)
• Multi-purpose lubricant (WD-40)
• Light bearing oil
• Silicone grease for gears

💰 Budget: €25-40/year

🔬 Specialty Products

• Differential silicone oils (3000-10000 WT)
• Silicone shock absorber oils (200-600 WT)
• After-run oil (thermal)
• Hydrophobic spray
• Electronic contact cleaner
• Threadlocker (blue/red)

💰 Budget: €40-70

📊 Diagnostic Tools

• Multimeter (voltage, continuity)
• Li-Po battery tester
• Infrared thermometer
• Magnifying glass (for crack inspection)
• Caliper

💰 Budget: €30-80 (optional)