Transmission Cooler Lines

Replace transmission cooler lines on a 2017 Maserati Levante 3.0L V6 Twin Turbo, including draining transmission fluid, removing old lines, installing new lines, and refilling with ZF Lifeguard 8 fluid.

Warnings

Tools required

Parts

• Transmission cooler line set (inlet and outlet) × 1 — Use OEM specification
• Transmission cooler line O-rings/seals × 1 — Usually included with line set
• Transmission drain plug crush washer × 1 — Use OEM specification
• Undertray clips and fasteners × 1 — Replace any damaged clips

Fluids

• ZF Lifeguard 8 — 10 qt

Preparation

1. Park vehicle on level surface and allow to cool completely for at least 2 hours
2. Disconnect negative battery terminal to prevent electrical faults
3. Raise vehicle securely on jack stands at all four corners to provide adequate working clearance
4. Remove engine undertray and protective covers to access transmission and cooler lines
5. Place large drain pan under transmission drain plug area
6. Locate transmission cooler lines running from transmission to radiator-mounted cooler (passenger side of vehicle)

Procedure

1. 1

   Drain transmission fluid
   Position drain pan under transmission drain plug located on bottom of transmission pan. Remove drain plug using appropriate socket and allow fluid to drain completely. Inspect drain plug and washer for damage. Install new crush washer on drain plug and reinstall drain plug hand-tight initially.
   Torque spec

   Drain Plug35 Nm (26 lb-ft)
2. 2

   Access transmission cooler line connections at transmission
   Locate the two cooler line connections on the driver's side of the transmission housing. Clean the area around the fittings with brake cleaner and shop rag. These are quick-connect style fittings on the Levante ZF 8HP transmission. Identify the supply (hot) line coming from transmission and return (cooler) line going back to transmission.
3. 3

   Disconnect cooler lines at transmission
   Using appropriate quick-connect line disconnect tool, depress the locking collar on each transmission cooler line fitting while pulling the line away from the transmission. Allow any residual fluid to drain into pan. Mark or photograph line positions to ensure correct reinstallation. Inspect the transmission-side fittings for damage or debris.
   ⚠Do not use excessive force or pliers on quick-connect fittings as this will damage the locking mechanism and cause leaks.
4. 4

   Trace and disconnect lines at radiator cooler
   Follow both cooler lines from transmission to the transmission cooler section integrated into the radiator assembly (lower passenger side). Remove any clips or brackets securing lines to chassis or subframe. At the radiator cooler, use line wrenches to loosen the threaded fittings. Have a drain pan positioned as residual fluid will drain. Cap or plug radiator cooler ports to prevent contamination.
5. 5

   Remove old transmission cooler lines
   Carefully extract both cooler lines from the vehicle, noting the routing path, bracket locations, and any grommets or mounting points. Check for interference points or areas where lines may have rubbed. Take photographs of routing for reference during installation. Inspect old lines for signs of damage, chafing, or leaks to determine root cause of failure.
6. 6

   Prepare and install new cooler lines
   Unpack new cooler line set and verify all O-rings and seals are included and properly positioned on fittings. Lubricate O-rings lightly with clean ZF Lifeguard 8 fluid. Route new lines following the same path as original lines, ensuring proper clearance from exhaust components, suspension parts, and sharp edges. Install all mounting brackets and clips loosely to allow final positioning adjustment.
7. 7

   Connect lines at radiator cooler
   Thread cooler line fittings into radiator cooler ports hand-tight, ensuring correct line identification (supply vs return). Use line wrenches to tighten fittings securely. Typical specification for these flare fittings is snug plus 1/6 turn (60 degrees) after hand-tight, but do not over-tighten aluminum fittings. Verify fittings are seated properly without cross-threading.
   ⚠Aluminum cooler fittings in radiator can strip if over-torqued. Tighten carefully by feel, not excessive force.
8. 8

   Connect lines at transmission
   Push each cooler line quick-connect fitting straight into the corresponding transmission port until an audible click is heard. Tug gently on each line to verify it is locked in place. The fitting should not pull free with moderate force. Ensure correct line routing (supply to supply, return to return) based on your earlier marking or factory routing diagram.
9. 9

   Secure all mounting points and verify clearances
   Tighten all line mounting brackets and clips securely. Verify cooler lines have at least 15mm clearance from exhaust components, driveshaft, and suspension members through full range of motion. Ensure lines do not contact sharp edges. Manually cycle steering lock-to-lock while verifying no interference with cooler lines.
10. 10

    Refill transmission with ZF Lifeguard 8 fluid
    Using fluid transfer pump, add approximately 9 quarts of ZF Lifeguard 8 fluid through the transmission fill tube located under the hood (driver's side of engine bay). This is preliminary fill; final level will be checked at operating temperature. Verify drain plug is torqued properly before filling.
    ⚠Only use genuine ZF Lifeguard 8 fluid. Generic ATF will cause irreversible transmission damage and void warranty.
    Torque spec

    Drain Plug35 Nm (26 lb-ft)
11. 11

    Reinstall underbody protection and lower vehicle
    Reinstall engine undertray and all protective covers removed during disassembly, replacing any damaged clips. Verify all fasteners are secured. Lower vehicle from jack stands to ground level. Reconnect negative battery terminal.
12. 12

    Check fluid level and test for leaks
    Start engine and allow to idle. Shift through all gear positions (P-R-N-D-Manual modes), pausing 3 seconds in each position. Return to Park. With engine idling and transmission at operating temperature (80-90°C, approximately 15-20 minutes of idling), check fluid level according to Maserati procedure using dipstick or scan tool level check procedure. Add fluid as needed to bring to proper level. Inspect all cooler line connections for leaks while engine is running.
    ⚠️Keep hands and tools clear of moving engine components and hot exhaust during fluid level check procedure.

Reassembly

1. Torque transmission drain plug to specification with new crush washer installed
2. Ensure all cooler line quick-connect fittings are fully seated and locked at transmission
3. Verify proper clearance of cooler lines from all heat sources and moving components
4. Final fluid level must be checked at operating temperature per manufacturer procedure

Verification

• Start engine and verify no transmission fluid leaks at cooler line connections (transmission and radiator ends)
• With vehicle at operating temperature, confirm transmission fluid level is within specification using proper checking procedure
• Test drive vehicle through all gears and verify smooth transmission operation with no slipping or delayed engagement
• After test drive, re-inspect all cooler line connections for signs of seepage or leaks while engine is warm
• Verify no transmission warning lights or fault codes are present using diagnostic scan tool

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