Plastic fuel tank – Toyota Land Cruiser 100 – dizel/petrol

Step-by-Step Guide to Replacing the Fuel Tank on a Toyota Land Cruiser 100 – dizel/petrol

Safety first: If you’re not comfortable working with fuel systems or heavy lifting, hire a professional.

Below is a clear, workshop-style step-by-step guide for removing and replacing the fuel tank on a Toyota Land Cruiser 100 series (both petrol and diesel). I include safety cautions, the common tools/parts, practical tips (what’s usually the hard part), and testing steps.

Quick overview (what this job involves)

Remove fuel from the tank (or isolate the system), disconnect electrical and fuel/vent lines (often via an access panel under the rear seat), support the tank with a jack, unbolt the 2 straps, lower the tank enough to disconnect the sending-unit connector and hoses, remove the tank, fit the replacement tank, then reassemble and test.

Safety first (don’t skip these)

• Work outdoors or in a very well-ventilated area. No open flames, sparks, or smoking.
• Have a rated fire extinguisher and absorbent pads handy.
• Wear eye protection, gloves, and protective clothing.
• Relieve fuel system pressure before disconnecting fuel lines (follow the vehicle service manual or the procedure below).

Tools & consumables (typical)

• Floor jack + wood block under the tank for protection
• Jack stands (support vehicle safely)
• Socket set: ratchet, extensions, breaker bar (commonly 10mm / 12mm / 14mm sockets; strap bolts often accessed with 14mm — use the correct size).
• Torque wrench (for reinstallation to spec)
• Fuel siphon pump and approved fuel container (if you need to drain fuel)
• Fuel line quick-disconnect tool (Toyota-style) or pick set for clamps
• Penetrating oil (PB Blaster / WD-40), hammer, pry bars for stuck straps/bolts
• Hose clamps, new rubber fuel hoses, new O-rings/sealing gasket for fuel pump/sender (recommended), replacement strap bolts/nuts (use OEM parts if possible).

What’s different: petrol vs diesel (short)

• Procedure (unbolt straps, lower tank, disconnect sending unit) is the same for both engines on the LC100.
• Specific lines you’ll see on each vehicle can differ: petrol models tend to have EVAP/charcoal canister plumbing and smaller quick-disconnect lines; diesel models may have additional return lines and pre-filters. Always identify and label hoses before removing.

Step-by-step: remove the old tank

(Do each step carefully; read the whole procedure once before starting.)

1. Park & prepare

• • Park on level ground, chock wheels. Put transmission in Park (auto) or reverse (manual) and set the parking brake.

  • Disconnect the negative battery terminal. Wait a few minutes.

2. Relieve fuel system pressure

• • Locate and remove the fuel pump relay (or fuse). Turn the ignition to ON (do NOT start) — the pump will prime briefly then stop. Crank the engine until it stalls to remove remaining pressure. (Alternatively follow the service manual’s bleed procedure.)

3. Access the top of the tank

• • Remove the rear seat or access panel and locate the fuel pump/sender electrical connector and fuel lines. Disconnect the electrical connector and any accessible hoses from above — freeing what you can makes the tank removal easier. Many LC100 owners recommend disconnecting as much as possible from above first.

4. Lower the spare tire & remove obstacles (if required)

• • Depending on year/fitment you may remove spare wheel, heat shields or tailpipe hangers to gain clearance. Some procedures recommend removing the tailpipe clamp/bolt in the removal path.

5. Support the tank

• • Place a floor jack under the tank (use a wood block to spread load and protect the tank). Slightly lift to take weight off the straps before undoing bolts.

6. Disconnect filler, vent, and fuel hoses

• • From underneath, loosen and remove the filler hose and vent hoses near the rear cross member. Use hose clamp pliers or cut if replacing later. Label hoses.

7. Unbolt the tank straps

• • Most LC100s have two straps (each with 2 main bolts). Remove the strap bolts (penetrating oil helps if rusted). Keep an eye on any bracket bolts that mount close to the tank. Important: don’t fully drop the tank yet — lower it a little and double-check for any remaining connections.

8. Lower tank partially & disconnect the sender/lines

• • Slowly lower the tank until you can reach the sending unit/fuel pump electrical connector and the main fuel lines that couldn’t be reached earlier. Disconnect the electrical connector and fuel lines now (cover open ports with clean rags or caps to prevent contamination).

9. Remove the tank

• • Carefully maneuver the tank around the drive shaft and exhaust — the LC100 tank is awkward and often requires a helper and some gentle twisting and tilting to clear. Keep fuel sloshing to a minimum (if tank is >50% full, siphon some fuel into an approved container first).

Preparing & installing the replacement tank

1. Prep the sender/pump

• • If re-using the fuel pump/sender, clean the top area before removing it from the old tank. Replace the sender gasket (O-ring) with a new one. If using a new tank that requires adapting the sender or lengthening hoses/wires, do that on the bench per the kit instructions.

2. Fit tank, raise into place

• • With the jack, lift the replacement tank into position. Start the strap bolts by hand (do not torque yet). If your tank kit supplied new reinforcing brackets or longer bolts, follow the kit instructions.

3. Reconnect hoses & electrical

• • Reconnect the filler/vent hoses, fuel lines, and sender electrical connector. Ensure EVAP lines and vent hoses are correctly routed and not kinked.

4. Torque hardware to spec

• • Tighten strap bolts and other fasteners to OEM torque specs. (If you don’t have the service manual at hand, use OEM torque specs — replacing rusted bolts with new OEM hardware is strongly recommended.)

5. Lower vehicle & test

• • Reconnect battery. Add a small amount of fuel (enough to cover the pump pickup). With someone monitoring for leaks, turn the ignition to ON (pump will prime). Check for leaks at all hose connections and the sender flange. If all good, top up the tank and do a short engine run to final-check.

Practical tips & common problems

• Rusted bolts/straps: soak overnight with penetrating oil, use impact tools, or cut and replace the bolt if necessary. Many owners replace strap bolts with OEM replacements as part of the job.
• Tank won’t clear the driveshaft/exhaust: use a helper, slowly tilt/rotate tank while watching hoses — patience and small adjustments beat brute force.
• Keep contaminants out: cover open ports immediately after disconnecting and clean the top of the sending unit before bench work.

Final checklist before driving

• All hoses reconnected and clamped.
• Electrical connector to sender firmly clipped.
• No fuel smell / no visible leaks.
• Strap bolts tightened to spec, extra nuts installed if required.
• EVAP/vent lines reconnected and routed correctly.
• Test drive with caution; recheck for leaks after the drive.