### Gearbox Torque Converter Clutch Repair on Mitsubishi 4G6 4G6-EW

#### Tools Required:
- **Basic Hand Tools:**
- **Socket Set:** Use to remove and tighten bolts. Common sizes include 10mm, 12mm, and 14mm. Ensure they fit the bolts securely.
- **Ratchet Wrench:** Works with the socket set to provide leverage for loosening/tightening bolts.
- **Torque Wrench:** Required to ensure bolts are tightened to manufacturer specifications. Important for preventing over-tightening which can damage components.
- **Screwdrivers (Flathead & Phillips):** Useful for removing clips and covers.

- **Specialized Tools:**
- **Torque Converter Clutch Tool:** If available, this tool will help in the disassembly and reassembly of the torque converter clutch assembly. It can simplify the process.
- **Transmission Fluid Pump:** To remove old transmission fluid without making a mess. Necessary for maintaining cleanliness and proper fluid levels during reassembly.

- **Additional Tools:**
- **Pliers:** For gripping and pulling components that may be difficult to remove by hand.
- **Oil Catch Pan:** To collect old transmission fluid during the process. Prevents spills and keeps your workspace clean.

#### Steps for Repair:
- **Preparation:**
- Park the vehicle on a level surface and engage the parking brake.
- Disconnect the negative battery terminal to prevent electrical shorts.

- **Fluid Removal:**
- Use the transmission fluid pump to drain old transmission fluid into the oil catch pan.
- Ensure you dispose of the old fluid following local regulations.

- **Accessing the Torque Converter:**
- Remove any underbody panels or covers that obstruct access to the transmission.
- Locate the torque converter, typically found at the front of the transmission.

- **Removing the Torque Converter:**
- Disconnect any electrical connectors or hoses attached to the torque converter.
- Use the socket set to remove the bolts securing the torque converter to the flex plate.
- Gently pull the torque converter away from the transmission.

- **Inspecting the Torque Converter Clutch:**
- Check for signs of wear, such as cracks or excessive scoring. If found, replacement is necessary.
- Replacement parts may include the torque converter itself or the clutch assembly if damaged.

- **Replacing the Torque Converter Clutch:**
- If replacement is needed, install the new torque converter clutch according to the manufacturer’s instructions.
- Make sure all seals and gaskets are replaced to prevent leaks.

- **Reinstallation:**
- Align the torque converter with the flex plate and secure it with bolts using the torque wrench to the specified settings.
- Reconnect any electrical connectors and hoses that were previously removed.

- **Refilling Transmission Fluid:**
- Refill the transmission with new fluid, following manufacturer specifications for type and amount.
- Start the engine and let it idle, checking for leaks and ensuring the fluid circulates properly.

- **Final Checks:**
- Reinstall any underbody panels or covers.
- Reconnect the negative battery terminal.
- Test drive the vehicle to ensure proper operation of the torque converter clutch.

#### Replacement Parts:
- **Torque Converter Clutch:** If the clutch is slipping or damaged, it needs to be replaced to restore proper function.
- **Seals and Gaskets:** Always replace these to avoid future leaks.

#### Conclusion:
Ensure you follow all safety precautions while working on the vehicle. If unsure about any step, consult a professional or refer to a repair manual specific to your Mitsubishi model.
rteeqp73

### Brake Line Replacement on a Mitsubishi 4G6 (4G6-EW)

#### **Theory Behind Brake Line Replacement**

**Purpose of Brake Lines:** Brake lines are essential components of your vehicle's braking system, which transfers brake fluid from the master cylinder to the brake calipers at each wheel. This fluid creates hydraulic pressure, enabling the brakes to function effectively.

**Why Replacement is Needed:**
- **Corrosion:** Over time, brake lines can corrode due to exposure to moisture, salt, and other environmental factors.
- **Leaks:** Damaged or worn-out lines can develop leaks, leading to a loss of brake fluid, which compromises braking performance.
- **Safety:** A malfunctioning brake system can lead to brake failure, posing a severe safety risk.

#### **How the Brake System Works**

Think of the brake system as a water hose. When you press the brake pedal, you push on the master cylinder, which sends brake fluid through the brake lines (like water through a hose) to the brake calipers. The calipers then squeeze the brake pads against the brake rotors, slowing down or stopping the vehicle.

#### **Components Needed for Brake Line Replacement**

1. **New Brake Line:** Ensure it’s the correct length and material (usually steel or copper).
2. **Brake Line Fittings:** These connect the lines to the brake components.
3. **Brake Fluid:** Make sure you have the correct type (check your manual).
4. **Wrenches/Sockets:** To remove old lines and install new ones.
5. **Brake Line Tool:** A pipe cutter and flare tool for cutting and flaring the new line.
6. **Ratcheting Wrench:** For tight spaces.
7. **Brake Cleaner:** To clean any spilled fluid and parts.
8. **Safety Glasses:** For eye protection.
9. **Jack and Jack Stands:** To lift the vehicle safely.
10. **Pliers and Screwdrivers:** For various tasks.

#### **Steps to Replace Brake Lines**

1. **Preparation:**
- Park the vehicle on a flat surface and turn off the engine.
- Wear safety glasses and gloves.
- Gather all tools and materials.

2. **Lifting the Vehicle:**
- Use a jack to lift the front or rear of the vehicle, depending on where the brake line needs replacing.
- Secure the vehicle with jack stands.

3. **Removing the Old Brake Line:**
- Locate the damaged brake line. Follow it from the master cylinder to the wheel.
- Use a wrench to loosen the fittings at both ends of the line (master cylinder and brake caliper). Keep a pan underneath to catch any leaking brake fluid.
- Remove the line completely.

4. **Preparing the New Brake Line:**
- Measure the old line to cut the new line to the same length.
- Use a pipe cutter to cut the new line.
- Use a flare tool to create a proper end on the new line that fits the fittings.

5. **Installing the New Brake Line:**
- Attach one end of the new line to the brake caliper and tighten the fitting with a wrench.
- Route the line carefully along the same path as the old line, avoiding any moving parts or heat sources.
- Attach the other end to the master cylinder and tighten.

6. **Bleeding the Brake System:**
- Fill the master cylinder with brake fluid.
- Start bleeding the brakes to remove any air trapped in the lines. This usually requires a helper:
- Have your assistant press the brake pedal several times and hold it down.
- Open the bleeder valve on the caliper to allow fluid and air to escape. Close the valve before your assistant releases the pedal.
- Repeat this process until no air bubbles are seen in the fluid.

7. **Testing the System:**
- Check all connections for leaks.
- Press the brake pedal; it should feel firm. If it feels spongy, repeat the bleeding process.
- Lower the vehicle and do a test drive to ensure brakes are functioning properly.

#### **What Can Go Wrong**

- **Improper Fitting:** If the line isn't tightly connected, it can leak fluid, leading to brake failure.
- **Air in the System:** If not bled properly, it can cause a spongy brake feel.
- **Incorrect Length of Line:** Too short or too long can lead to improper routing or stress on the line.

### Final Thoughts

Replacing brake lines is a critical maintenance task that keeps your vehicle safe. Always prioritize safety when working on your brakes, and don’t hesitate to seek professional help if you feel uncertain about any step in the process.
rteeqp73

Replacing the gearbox seal on a Mitsubishi 4G6 4G6-EW involves a systematic approach rooted in understanding the seal's function and the gearbox's operation. Here's an explanation of the theory and the repair process:

### Theory:

1. **Function of Gearbox Seals**: Gearbox seals prevent the leakage of transmission fluid and protect internal components from contaminants. They maintain pressure and lubrication, ensuring the smooth operation of gears and bearings.

2. **Fault Cause**: Over time, seals can wear, become brittle, or be damaged due to heat, pressure, or contaminants. This can lead to fluid leaks, which can cause low fluid levels, overheating, and ultimately gearbox failure.

3. **Repair Objective**: The goal of seal replacement is to restore the integrity of the gearbox, ensuring proper sealing to maintain lubrication and prevent leaks.

### Replacement Process:

1. **Preparation**:
- Gather tools: seal puller, socket set, torque wrench, and replacement seals.
- Ensure the vehicle is on a level surface and secure it with jack stands.

2. **Drain Fluid**:
- Remove the drain plug and allow transmission fluid to fully drain. This prevents fluid from spilling during seal replacement and reduces the risk of contamination.

3. **Access the Seal**:
- Depending on the seal location (front, rear, or side of the gearbox), you may need to remove associated components (like the driveshaft or transmission mount) to gain access.

4. **Remove Old Seal**:
- Use a seal puller or a similar tool to carefully extract the old seal without damaging the gearbox housing. Inspect the seal surface for wear or scoring.

5. **Clean Seal Housing**:
- Thoroughly clean the seal seat in the gearbox to remove debris, old sealant, or fluid residues. A clean surface ensures a proper fit for the new seal.

6. **Install New Seal**:
- Lubricate the new seal’s lip with clean transmission fluid. Align the seal properly and press it into the housing evenly to avoid distortion.

7. **Reassemble Components**:
- Reinstall any components removed for access, ensuring all bolts are torqued to manufacturer specifications.

8. **Refill Gearbox Fluid**:
- Replace the drain plug and refill the gearbox with the correct type and amount of transmission fluid.

9. **Test Drive**:
- Start the vehicle and take it for a short drive. Check for leaks and ensure smooth operation.

### Conclusion:

By replacing the worn or damaged seal, you restore the gearbox's ability to maintain fluid levels and pressure, preventing leaks and protecting internal components. This repair ultimately enhances the gearbox's reliability and longevity, addressing the fault that led to the need for replacement.
rteeqp73

- Safety first (read and follow every item before starting)
- Wear eye protection and gloves; brake dust can contain harmful material.
- Work on a flat, level surface with good lighting.
- Chock wheels that remain on the ground and set the parking brake.
- Never rely only on a jack to hold the car — always use properly rated jack stands on the manufacturer jacking points.
- Keep a fire extinguisher nearby if you will be handling brake fluid.

- Tools — what they are, why you need each, and how to use them
- Hydraulic floor jack
- Description: low-profile jack with a pump handle; lifts the car safely with less effort than a scissor jack.
- Why: lifts the vehicle high enough so you can put jack stands and remove the wheel.
- How to use: position the saddle under the vehicle's jacking point (check door sill/jack point), pump handle to raise slowly, never go under vehicle while supported only by the jack.
- Pair of jack stands (rated for vehicle weight)
- Description: adjustable metal stands with a locking pin or ratchet.
- Why: to support the vehicle safely while you work.
- How to use: set to the same height on both sides, lower the car onto stands slowly, check stability before removing jack.
- Wheel chocks
- Description: rubber or plastic wedges placed behind wheels.
- Why: prevent the car from rolling.
- How to use: place behind/forward of tires not being lifted.
- Lug wrench or breaker bar with appropriate sockets (carry a 17 mm and 19 mm socket; full metric set 10–24 mm recommended)
- Description: cross wrench or long-handled breaker/ratchet and sockets.
- Why: to remove and reinstall wheel lug nuts.
- How to use: loosen lug nuts slightly while the car is on the ground (use your body weight), fully remove after car is raised.
- Ratchet and metric socket set (10–24 mm), deep sockets helpful
- Description: 3/8" or 1/2" drive ratchet with a range of sockets.
- Why: to remove caliper bolts, bracket bolts, and other fasteners.
- How to use: pick the correct socket, pull to break loose, keep bolts and parts organized.
- Torque wrench (range covering lug nut torque)
- Description: calibrated wrench that clicks or displays when target torque reached.
- Why: to tighten lug nuts and caliper/bracket bolts to spec (safety and to prevent warping).
- How to use: set desired torque, tighten in correct pattern (wheel lug nuts in a star/cross pattern).
- C-clamp or dedicated brake piston compressor (large, flat jaws)
- Description: large clamp or tool that pushes the caliper piston back into the caliper bore.
- Why: create space for new, thicker pads so the caliper can reassemble.
- How to use: place old pad over piston as protection, close clamp slowly until piston is fully compressed flush with caliper.
- Flat-blade screwdriver and small pry bar
- Description: hand prying tools.
- Why: to lever off pads, remove retaining clips, and gently free stuck parts.
- How to use: apply steady pressure; avoid prying on flexible rubber parts.
- Wire brush and shop rags
- Description: metal brush and lint-free rags.
- Why: clean caliper bracket grooves, pad contact surfaces, remove rust.
- How to use: brush away rust and deposits, wipe clean with rags.
- Brake cleaner spray
- Description: solvent aerosol designed to remove grease and brake dust.
- Why: cleaning rotors and caliper surfaces safely and quickly.
- How to use: spray onto parts and wipe; avoid breathing vapors.
- High-temperature brake grease (silicone/ceramic based) and small brush or applicator
- Description: paste designed for pad backing, shims, and slide pins.
- Why: prevent noise and ensure smooth sliding of caliper pins.
- How to use: apply thin layer to metal-on-metal contact points (not to friction surface).
- Rubber gloves and drain pan
- Description: gloves and container to catch fluid or debris.
- Why: protect hands and collect any fluid displaced to avoid spills.
- Caliper slide pin grease (lubricant) and new rubber boots if needed
- Description: grease formulated for brake slide pins.
- Why: to ensure the caliper slides freely.
- How to use: remove pins, clean, apply grease, reassemble with intact boots.
- Brake pad spreader or piston retraction tool (optional, for twins and some rear calipers)
- Description: a tool that pushes the piston back evenly.
- Why: sometimes required instead of a C-clamp for even pressure.
- How to use: follow tool instructions to retract piston squarely.
- Small digital caliper or micrometer (optional but recommended)
- Description: measuring tool for rotor thickness.
- Why: determine if rotors are above minimum thickness or need replacement.
- How to use: measure rotor at multiple spots; compare to minimum thickness stamped on rotor or service spec.
- Brake fluid syringe or turkey baster (optional)
- Description: pump or baster to remove excess fluid from master cylinder reserve.
- Why: prevents overflow when compressing pistons; also used when changing fluid.
- How to use: remove cap and siphon out some fluid before compressing piston.
- Bleeder wrench or line wrench, clear tubing and bottle (only if doing brake bleeding)
- Description: small wrench that fits bleeder nipple and tubing to capture fluid.
- Why: to bleed air out of brake lines if needed after replacement.
- How to use: attach tubing to nipple, open slightly, have helper press brake pedal, close nipple, repeat until clear fluid.
- Special tools you may need (why they might be required)
- Electronic parking brake (EPB) service tool or manufacturer procedure
- Why: many modern Mitsubishis with EPB require a specific tool or diagnostic software to retract the rear caliper piston electronically. If your car has an EPB, a simple C-clamp may not work and forcing it can damage the mechanism.
- Rotor puller or gentle mallet
- Why: rotors sometimes seize to the hub; a rotor puller or controlled hammer taps on the rotor hub face will free it.
- Bench vise (optional)
- Why: useful for compressing pistons off-vehicle using a piston compressor plate.

- Parts — what you likely need, why, and when replacement is required
- Brake pads (front and/or rear)
- Why: friction material wears; pads are the normal wear item and must be replaced when below manufacturer thickness or causing poor braking, noise, or vibration.
- What to buy: OEM or reputable aftermarket pads specified for your Mitsubishi 4G6 model and year. Buy full set for an axle (both pads on the same axle).
- Brake rotors/discs (may be required)
- Why: scoring, grooving, excessive runout (warp), or thickness below minimum requires rotor resurfacing or replacement. Thin rotors overheat easily and are unsafe.
- What to buy: OEM-spec rotors or quality aftermarket. If rotors are within spec and surface is good, you can reuse them; otherwise replace or have machined if within min. thickness.
- Caliper hardware kit (shims, anti-rattle clips)
- Why: old clips can be corroded and cause noise or uneven wear; new hardware ensures pads sit correctly.
- What to buy: hardware kit matched to caliper/pad set.
- Caliper slide pins or guide bolts (if worn)
- Why: seized or corroded pins cause uneven pad wear and sticking calipers.
- What to buy: new pins or rebuild kit with boots and grease.
- Brake fluid (DOT specification from owner's manual)
- Why: if you need to bleed the system or fluid level was high when compressing pistons, top up or flush. Old fluid absorbs moisture and reduces boiling point.
- What to buy: DOT 3/4/5.1 as specified in manual (do not mix DOT 5 silicone with DOT 3/4/5.1).
- Pad wear sensors (if equipped on your vehicle)
- Why: sensors alert you when pads are low; if broken during removal, replace.
- What to buy: sensor compatible with your model.

- Step-by-step procedure (high-level but complete — follow each bullet in order)
- Prepare
- Park on level ground, chock wheels, loosen lug nuts while car is on the ground (break them a half-turn each).
- Open hood, remove master cylinder cap and check fluid level; remove a small amount if it is close to max to prevent overflow when compressing pistons.
- Lift and secure vehicle
- Use the floor jack to lift the vehicle at the correct jacking point, install jack stands, lower the car onto stands and remove the jack.
- Remove the wheel lug nuts and wheel; keep lug nuts safe.
- Expose the brake caliper and pads
- Spray brake cleaner on caliper area to remove surface grime.
- Identify caliper mounting bolts (may be 2 bolts on back of caliper or sliding pins depending on design).
- Remove caliper from bracket
- Use the correct socket to remove caliper guide/slide bolts; support the caliper with a bungee cord or hang from suspension—do not let it hang by the brake hose.
- If bolts are stubborn, use penetrating oil, heat carefully with a torch only if you know what you're doing.
- Remove old pads and hardware
- Slide the pads out of the bracket; note orientation and any shims/clips for correct reinstallation.
- Remove old anti-rattle clips/shims and clean the bracket grooves with wire brush.
- Inspect rotors and caliper components
- Look for deep grooves, heavy rust, cracks, or blue discoloration on rotors — these are signs of overheating or damage.
- Measure rotor thickness at several points; compare to the minimum thickness stamped on the rotor or in a service manual. Replace if below min, if scored deeply, or if you get pedal pulsation.
- Inspect caliper piston and boots for leaks or damage; inspect flexible brake hose for cracks. Replace caliper or hose if leaking or badly damaged.
- Retract the caliper piston
- Place old pad over piston to protect it, position the C-clamp across the caliper and slowly tighten to push the piston back into the bore until flush.
- If piston must be rotated (some rear calipers with parking brake have a screw-in piston), use the correct turning adapter or follow the rotor/vehicle-specific method; for EPB, use service tool or procedure — do not force.
- Fit new hardware and pads
- Install new anti-rattle clips/shims into the caliper bracket grooves.
- Lightly coat the metal contact points (where pad slides) with high-temp brake grease — do not contaminate the pad friction surface or rotor with grease.
- Install new pads into the bracket in the same orientation as removed.
- Refit caliper and torque bolts
- Slide the caliper over the new pads and rotor; reinstall slide pins or caliper bolts and torque to manufacturer specs (if you don’t have the manual, torque caliper guide bolts snugly and check a reliable source for the correct torque).
- Make sure the caliper slides freely after greasing pins and reinstalling boots.
- Reinstall wheel and lower vehicle
- Refit wheel, hand-tighten lug nuts, lower the car to the ground, then torque lug nuts in a star pattern to the proper torque.
- Final steps and bleed/check
- With car still off, pump the brake pedal several times until you get a firm pedal — this seats the pads against the rotor.
- Check brake fluid level and top up to the correct level with the correct type.
- If the pedal feels spongy or you opened a bleeder, bleed the brake line(s) until firm. Follow the correct sequence for your vehicle (normally farthest wheel to nearest).
- Test drive and bed-in procedure
- Start with low-speed stops to confirm normal braking and no pulling, noise, or leaks.
- Perform a pad bed-in procedure: several moderate stops from 30–40 mph to about 5–10 mph (do not lock wheels), with cooling intervals — follow pad manufacturer instructions for best results.
- Re-check everything after first 50–100 miles: retorque lug nuts, inspect for leaks, check fluid.

- Common problems and how to address them
- Squeal/noise after replacement
- Ensure shims/clips are installed, grease contact points, and that pads are clean of grease/contaminants. Some pads require a thin layer of anti-squeal compound.
- Soft or spongy pedal
- Air in the lines — bleed brakes. Also check master cylinder level and for leaks.
- Car pulls to one side
- One caliper may be sticking; verify slide pins move freely and caliper piston returns properly. Check pad wear for unevenness.
- Rotor runout/pedal pulsation
- Check rotor for lateral runout; if excessive, replace rotor or have it resurfaced if within thickness spec.

- Disposal and environmental/legal notes
- Dispose of old pads, brake fluid, and contaminated rags according to local hazardous waste regulations — do not throw used fluid down drains.
- Keep receipts and part numbers in case of warranty or returns.

- Quick checklist of parts to buy before starting
- Brake pads (complete axle set)
- Hardware kit (clips/shims) for that axle
- New rotor(s) if rotors are below min thickness or damaged
- Brake grease and caliper pin grease
- Brake fluid (correct DOT type) if topping up or bleeding
- Pad wear sensors if your vehicle uses them and any are damaged

- Final safety reminder
- If at any point you are unsure, cannot compress the piston, encounter an electronic parking brake that will not retract, see leaking components, or do not get a firm pedal after bleeding, stop and consult a professional mechanic. Improper brake work is dangerous.

(Performing brake service correctly requires attention to detail and adherence to torque and safety specs. If you want, I can give model-year–specific torque numbers and recommended pad/rotor part numbers if you provide the exact Mitsubishi model and year — otherwise use the general guidance above.)
rteeqp73