Tools & consumables
- Full metric socket & wrench set (6–24 mm), extensions, swivel.
- Torque wrench (up to ~200 Nm), breaker bar.
- Harmonic balancer / crank pulley holding tool and puller.
- Crankshaft locking pin (engine-specific) or service locking tool.
- Camshaft holding/locking tool(s) for your engine (engine-specific — required on many Toyota engines).
- Timing chain tensioner compressor or pin (to compress or lock hydraulic tensioner).
- Screwdrivers, pliers, pry bar.
- Engine support bar or jack with block under oil pan (for support when engine mounts are removed).
- Gasket scraper, degreaser, lint-free rags.
- RTV sealant (as per factory spec), new gaskets.
- New timing chain kit (chain, guides, rail(s), tensioner) and any replacement sprockets if worn.
- New valve cover gasket, front timing cover gasket, crankshaft front oil seal (recommended).
- Replacement bolts if service manual calls some “one-use” (torque-to-yield) — commonly cam/crank sprocket bolts may be single-use.
- Engine oil and filter, coolant (if drained), thread locker where specified.
- Safety: gloves, safety glasses, wheel chocks, jack stands.

Safety precautions
- Work on level ground, wheels chocked, parking brake on.
- Disconnect negative battery terminal before starting.
- Support vehicle safely on jack stands; do NOT rely on a jack alone.
- If engine mounts or subframe/supports are removed, support engine from above with an engine support bar or from below with a jack and wood block under oil pan.
- Relieve fuel system pressure (diesel/petrol) and take fuel-system safety measures when removing lines.
- Drain coolant/oil into proper containers and dispose per local regs.
- Keep open hands/loose clothing away from moving parts when running engine for checks.

General notes before you start
- There are multiple Hilux engines (1TR-FE, 2TR-FE petrol; 1KD-FTV, 2KD-FTV diesel, etc.). Procedures and special tools vary. Always reference the factory service manual for your engine for specific timing marks, lock tools, and torque values.
- Replace timing chain, tensioner, guides together as a kit. Always install a new hydraulic tensioner; reusing old tensioners risks premature failure.
- Replace front crank oil seal and valve cover gasket while cover is off — inexpensive insurance.

Step-by-step procedure (typical Toyota chain install)
1) Preparation
- Park, chock wheels, disconnect negative battery terminal.
- Remove engine undertray if present.
- Drain engine oil and coolant if required by timing cover removal.

2) Remove obstructing components
- Remove intake resonator and air cleaner assembly for access.
- Remove accessory drive belts, alternator, A/C compressor (or unbolt and move aside without disconnecting hoses if space), power steering pump or bracket as needed.
- Remove radiator fan/shroud if it blocks access. Remove radiator if necessary for room.
- Remove crankshaft pulley/harmonic balancer: use holding tool to prevent rotation, remove center bolt (breaker bar). Use puller if needed.
- Remove any engine front cover components (timing belt/chains sometimes behind a plastic or metal cover). Remove valve cover if required to access cam sprockets (you will need to see cam timing marks).

3) Set engine to TDC and lock cams/crank
- Rotate engine by crank bolt to bring No.1 cylinder to Top Dead Center (TDC) on compression stroke. Verify with timing marks on crank and cam sprockets — refer to manual for exact marks.
- Install crankshaft locking pin into timing cover hole if provided for your engine to prevent rotation.
- Use camshaft holding/locking tool to lock camshafts at the specified orientation. This prevents cams from moving when chain is removed.
- DO NOT rely solely on marks; use proper locking tools where specified.

4) Decompress/remove timing chain tensioner
- Retract or compress the hydraulic/mechanical tensioner and secure it in the compressed/locked position using the tensioner tool or locking pin supplied in the kit/manual. On hydraulic types, you may need to retract the plunger and insert a pin to hold it.
- Remove timing chain guides if they obstruct removal. Note orientation and location of each guide.

5) Remove chain and sprockets (if replacing)
- Remove camshaft sprocket bolts (some are torque-to-yield — replace if specified). Use cam holding tool to prevent cam rotation while loosening bolts.
- Remove chain from cam and crank sprockets. If replacing sprockets, remove and replace per manual.
- Inspect sprocket teeth, cam lobes, guides, tensioner, and bearings. Replace any damaged/worn sprockets.

6) Install new parts
- Clean all mating surfaces. Install new timing chain, guides, and new tensioner per kit instructions. Ensure chain orientation and timing marks line up exactly per service manual.
- For multi-row or offset chains, follow manufacturer sequence marking on chain links — usually colored links align with cam/crank marks. Use the illustration in the service manual or kit instructions.
- Fit chain over crank sprocket, then cam sprockets. Install cam sprocket bolts and torque to specified value in stages while cams are held by the locking tool. Use new bolts where required and apply thread locker if specified.

7) Preload and release tensioner correctly
- If the tensioner is a hydraulic plunger type, install it in compressed state or follow the kit instructions for priming/setting. Some tensioners are self-priming; others require preloading with a pin removed only after chain is installed and engine rotated.
- Ensure guides are fitted in correct orientation and torqued to spec. Do not overtighten plastic guide bolts.

8) Verify timing
- Remove cam and crank locking tools/pins only after everything is installed and torqued.
- Rotate the engine slowly by hand two full revolutions (720°) using the crank bolt. Stop at TDC and re-check alignment of all timing marks. If marks do not align, you must remove and correct chain installation.
- Check tensioner operation: for mechanical types, ensure proper tension; for hydraulic, allow engine to build oil pressure then check.

9) Replace seals & gaskets, reassemble
- Replace valve cover gasket and front timing cover/crank seal if disturbed. Apply RTV only where specified.
- Reinstall harmonic balancer/crank pulley, torque center bolt to spec while holding pulley with holding tool.
- Reinstall accessory components, belts, radiator fan/shroud, air intake, reconnect hoses and lines. Refill engine oil and coolant. Replace oil filter if desired.

10) Start-up & testing
- Reconnect battery.
- Prime fuel system if necessary. Start engine and idle; listen for unusual noise (ticking, rattle) for a few minutes — some hydraulic tensioners need time to settle but persistent rattle indicates improper installation or failed tensioner.
- Check for leaks (oil, coolant) and re-torque any accessible bolts after initial run per manual if required.
- Road test and re-check for codes, noises, leaks. After a warm-up cycle, re-inspect tensioner/guides for movement.

How the special tools are used (practical)
- Crankshaft locking pin: inserted into the timing cover/crankcase hole to lock crank at TDC. Prevents crank from turning when cam bolts are loosened.
- Camshaft locking tool: engages camshaft sprockets or cam lobes to hold them in the exact position while removing/installing the chain and torquing bolts.
- Crank pulley/harmonic balancer holding tool: holds the crank pulley in place while loosening or tightening the central bolt.
- Tensioner compressor/locking pin: compresses a hydraulic tensioner and locks it so the chain can be installed without tension. After installation and rotation, remove the pin to allow tensioner to seat.
- Harmonic balancer puller: if pulley is tight, used to remove without damaging crank snout.
Always use the correct engine-specific versions of these tools. Using incorrect tools can damage sprockets or cams.

Replacement parts recommended
- Complete timing chain kit: chain(s), all guides, rail(s), and tensioner (hydraulic or spring).
- Camshaft/crankshaft sprocket bolts (if specified as single-use).
- Valve cover gasket, timing cover/gasket, front crankshaft oil seal.
- Engine oil and filter, coolant if drained.
- Inspect and replace worn accessory belts, idlers, water pump (optional but recommended on high-mileage jobs).

Common pitfalls & how to avoid them
- Pitfall: Not using cam/crank locking tools and losing timing alignment.
- Fix: Use OEM-specified locking tools; verify marks twice.
- Pitfall: Incorrect tensioner preload or not releasing tensioner properly.
- Fix: Follow kit/manual sequence exactly; do not start engine until tensioner is released/primed per instructions.
- Pitfall: Reusing worn guides or old tensioner.
- Fix: Replace guides and tensioner with new kit.
- Pitfall: Overlooking torque-to-yield bolts and reusing them.
- Fix: Replace bolts that the manual specifies single-use.
- Pitfall: Rotating engine from cam sprocket — damage risk.
- Fix: Rotate by crank only when checking timing. Use holding tools for cams.
- Pitfall: Dropping fasteners into timing cover/oil passages.
- Fix: Keep a magnetic tray, cover openings with clean rag when removing parts.
- Pitfall: Not supporting engine when removing mounts/brackets.
- Fix: Use engine support bar or jack under oil pan with block; follow manual.
- Pitfall: Not checking/clearing OBD codes after reassembly.
- Fix: Scan ECU; clear codes and re-test.

Final checks
- Rotate engine by hand 2–3 times and verify all marks; check for binding.
- After starting, let idle until warm and re-check timing marks per manual if required.
- Re-check torque on critical fasteners after initial run if the manual recommends.

End.
rteeqp73

### Oil Cooler on a Toyota Hilux: Detailed Explanation

**Purpose of the Oil Cooler:**
The oil cooler is designed to regulate the temperature of the engine oil. Engine oil lubricates and protects engine components, but it can break down if it gets too hot. An oil cooler prevents overheating, ensuring that the oil maintains its viscosity and continues to protect the engine effectively.

### Components of the Oil Cooler System:

1. **Oil Cooler Core:**
- **Description:** A small radiator-like device with many fins to increase surface area.
- **Function:** It allows engine oil to flow through while air passes over it, dissipating heat.

2. **Oil Lines:**
- **Description:** Hoses that carry oil to and from the oil cooler.
- **Function:** Transport hot oil from the engine to the cooler and return cooled oil back to the engine.

3. **Thermostat:**
- **Description:** A valve that controls oil flow to the cooler based on temperature.
- **Function:** It opens when the oil is hot enough to be cooled and closes when the oil is at an acceptable temperature.

4. **Mounting Bracket:**
- **Description:** Metal bracket that secures the oil cooler to the vehicle frame or engine.
- **Function:** Keeps the oil cooler in place and ensures it is positioned properly for airflow.

5. **Oil Filter:**
- **Description:** A filter that removes contaminants from the oil before it enters the cooler.
- **Function:** Protects the cooler and engine from debris that can clog the system.

### How the System Works:

1. **Hot Oil from the Engine:**
- As the engine runs, it generates heat. The engine oil absorbs this heat as it circulates through the engine.

2. **Flow to the Cooler:**
- The hot oil is pumped through oil lines to the oil cooler. If equipped, the thermostat determines when to send the oil to the cooler based on temperature.

3. **Cooling Process:**
- Inside the oil cooler, the hot oil flows through the core. Air, either from the vehicle’s movement or a fan, passes over the cooler's fins, removing heat from the oil.

4. **Return to the Engine:**
- Once cooled, the oil is returned through the oil lines back to the engine, ready to continue lubricating and protecting engine components.

### Why This Repair is Needed:

- **Overheating Oil:** If the oil cooler is malfunctioning, the engine oil can overheat, leading to decreased lubrication and potential engine damage.
- **Oil Breakdown:** High temperatures can cause oil to break down, resulting in sludge and deposits that can clog passages.
- **Engine Efficiency:** Proper temperature regulation ensures that the engine runs efficiently, improving performance and fuel economy.

### What Can Go Wrong:

1. **Clogged Cooler:**
- **Issue:** Contaminants can block the cooler, preventing proper oil flow.
- **Analogy:** Like a dirty filter in a vacuum cleaner, it can’t suck up dirt efficiently.

2. **Leaking Oil Lines:**
- **Issue:** Oil can leak out, leading to low oil levels and potential engine failure.
- **Analogy:** Think of a garden hose with holes; water leaks out instead of reaching the plants.

3. **Thermostat Failure:**
- **Issue:** If the thermostat fails, it may either not allow oil to flow to the cooler or keep it flowing continuously, not allowing the engine to reach optimal temperature.
- **Analogy:** Like a faulty thermostat in your home that doesn’t regulate temperature properly.

4. **Damaged Cooler:**
- **Issue:** Physical damage can lead to leaks or reduced cooling efficiency.
- **Analogy:** Similar to a radiator with a crack that can’t hold water; it fails to cool the engine.

### Conclusion:

Understanding the oil cooler’s function and components is crucial for maintaining your Toyota Hilux. Regular checks can prevent issues associated with overheating oil, ensuring your engine remains in good working condition. Always replace or repair faulty components promptly to avoid severe engine damage.
rteeqp73

Tools & consumables
- Floor jack and rated jack stands (2) — use factory jacking point and stands rated ≥ vehicle weight.
- Wheel chocks.
- 1/2" breaker bar and appropriate socket for lug nuts.
- Torque wrench (range to ~150 Nm / 110 ft·lb).
- Socket set (metric), ratchet, extensions.
- Hex/Allen or torx sockets (for caliper guide/slider & bracket bolts — commonly 6 or 8 mm hex or 17–19 mm bolts depending on model year).
- Combination wrenches.
- C‑clamp or dedicated caliper piston tool (for retracting piston).
- Caliper hanger or bungee/zip ties.
- Screwdriver/pry bar (flat blade).
- Hammer or rubber mallet; punch for rotor screw removal.
- Penetrating oil (PB Blaster, WD‑40).
- Wire brush, emery cloth.
- Brake cleaner.
- High‑temp brake grease / silicone‑based caliper grease and copper anti‑seize.
- Shop rags, gloves, eye protection.
- New rotors (correct OEM or quality aftermarket); brake pads strongly recommended.
- Replacement hardware if specified (caliper bracket bolts, rotor screws, pad clips, guide pin boots).
- Brake bleeding kit only if you open fluid lines or piston replacement required.

Safety precautions (non‑negotiable)
- Work on a level surface. Chock wheels opposite axle. Engage parking brake.
- Loosen lug nuts slightly before jacking. Use jack stands; never rely on the jack alone.
- Wear eye protection and gloves. Keep respirator or work outdoors for brake dust. Avoid compressed air on old pads/rotors.
- Do not let caliper hang by brake hose — support with hanger/bungee.
- If you open hydraulic lines or replace caliper/piston, properly bleed brakes and dispose of fluid safely.

Step‑by‑step rotor replacement (front discs typical)
1) Prep
- Park, chock, set parking brake, slightly loosen lug nuts on wheel to be worked.
2) Lift & remove wheel
- Jack at factory lift point, place jack stands, remove lug nuts and wheel.
3) Inspect
- Note pad thickness, hardware condition, brake hose condition, ABS wiring/sensors.
- If pads are worn unevenly, expect to replace pads and check caliper condition.
4) Remove caliper
- Locate caliper guide/slide bolts (usually on back of caliper). Spray penetrating oil if stiff.
- Remove bolts with appropriate socket/allen. Pull caliper off rotor/bracket. Do NOT let it hang by hose — hang it from suspension with a bungee or hook.
- Remove brake pads from caliper bracket.
5) Remove caliper mounting bracket (if required)
- Many Toyota Hilux setups require removing the caliper mounting bracket to free the rotor. Remove the two bracket bolts and set bracket aside.
6) Remove rotor
- If there’s a small retaining screw on the rotor hat, remove it (Phillips or hex). Often rusted — use penetrating oil, punch and hammer or impact driver.
- If rotor is seized to hub from corrosion, strike the face of the rotor near the hub with a hammer or rubber mallet, or use two bolts threaded into rotor hat holes (if present) to push it off evenly. Apply penetrating oil and work it back and forth.
7) Clean hub
- Remove rust and old material from hub face with wire brush until flat and clean. Ensure rotor sits flush — uneven hub causes runout and vibration.
8) Fit new rotor
- Clean rotor faces with brake cleaner to remove protective oil.
- Slide rotor onto hub. If a retaining screw is present, reinstall lightly (do not over‑tighten).
- Apply a thin coat of copper anti‑seize to hub center (not brake face) to ease future removal.
9) Reinstall bracket & caliper hardware
- Reinstall caliper bracket and torque to factory spec.
- Replace pad hardware clips if corroded. Fit new or old pads (new pads recommended).
- Retract caliper piston: using a C‑clamp or piston tool, slowly press piston back into caliper while monitoring brake fluid reservoir level. If vehicle has internal parking brake on rear calipers, use the correct turning tool.
- Grease guide pins lightly with high‑temp caliper grease and reinstall. Replace boots if damaged.
- Reinstall caliper over pads/bracket; torque caliper bolts to spec.
10) Wheel & torque
- Refit wheel, finger‑tighten lug nuts, lower vehicle, torque lug nuts in a star pattern to factory spec (example range: 100–120 Nm / 74–89 ft·lb — confirm exact spec for your Hilux).
11) Final checks & bed‑in
- Pump brake pedal until firm before moving vehicle (retracting piston may require pumping).
- Check brake fluid level; top off with correct DOT fluid if needed.
- Test for leaks, ensure ABS sensor wires not pinched.
- Bed new pads/rotors: perform gradual stops from ~30–40 mph several times (about 8–10 moderate stops), then allow cooling. Avoid heavy braking for first 200 km.

How specific tools are used
- Breaker bar: initial lug nut removal and stubborn bolts.
- Torque wrench: final tightening of wheel nuts, bracket bolts, caliper bolts to specified torque.
- C‑clamp/piston tool: compresses caliper piston evenly to accept new, thicker pads. Turn piston in vehicles with integrated parking brake mechanism using the special tool.
- Penetrating oil + hammer/punch or impact driver: frees rusted rotor retaining screws or stuck rotor.
- Wire brush/emery cloth: cleans hub mating surface to ensure rotor runs true.
- Caliper hanger/bungee: prevents hose damage from hanging caliper.

Parts commonly replaced / required
- New rotors (matching OEM spec — check min. thickness stamped on rotor).
- Brake pads (strongly recommended to replace whenever rotor is replaced).
- Pad hardware/clips, anti‑rattle shims if corroded.
- Caliper guide pin boots or guide pins if seized.
- Caliper mounting bolts/hardware if single‑use or damaged.
- Brake fluid if topping or bleeding needed; cleaning solvents and anti‑seize.

Common pitfalls & how to avoid them
- Not cleaning hub surface — leads to rotor runout/vibration. Always clean and deburr.
- Letting caliper hang by hose — causes brake hose damage. Always support caliper.
- Contaminating pad or rotor with grease/oil — will cause noise, poor braking. Use brake cleaner; avoid touching friction surfaces.
- Not replacing pads with rotors — new rotors on old, glazed pads reduces performance and may cause uneven wear.
- Over‑compressing piston causing fluid overflow — monitor reservoir; remove excess fluid first if required.
- Reusing seized rotor screws — strip them; use penetrating oil and appropriate driver or replace screws.
- Insufficient torquing or uneven torque on wheel studs — leads to wheel vibration; always torque in star pattern to spec.
- Failing to bed‑in brakes — leads to glazing and reduced life.
- Not checking ABS sensors/wiring — can be damaged during job; inspect before reassembly.

When to bleed brakes or replace caliper
- If you open a hydraulic line, replace the caliper, or notice spongy pedal after compressing piston, bleed the brake system.
- If caliper piston or guide pins are seized, replace or rebuild caliper.

Notes on specifications
- Torque values vary by Hilux model and year. Use factory manual for exact torque values for wheel nuts, caliper bracket bolts, and caliper bolts. Example wheel torque commonly ~100–120 Nm (74–89 ft·lb) — confirm for your vehicle.

Done.
rteeqp73