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MajorCommonFluid Leaks

Ford Explorer: U502 6F55 Transmission Cooler Line Leak

U502 6F55 Transmission Cooler Line Leak is a common fluid leaks fault on the Ford Explorer on the 2011–2019 cars, and we rate it major. Putting it right costs $300 to $900 at New Zealand independent workshop rates. Below is what goes wrong, the symptoms to notice on a test drive, where to look, and what to ask the seller before you hand over any money. It is one of 11 documented faults on the Ford Explorer.

Vehicle
Ford Explorer
Years
2011–2019
Fuel
petrol
Gearbox
auto
System
Fluid Leaks

This page covers the Ford Explorer as a model. Some faults only affect particular engines or build years — enter a plate below to narrow the list to one car.

All Ford Explorer faults11 documented faults on this model

What you are looking at

No photograph available

We do not hold a verified photograph for this fault yet. We would rather show none than show a picture of something else.

What goes wrong

The 6F55 six-speed automatic transmission in the U502 Explorer has documented cooler line fitting leaks at the transmission case connections. Quick-connect fittings and the line body itself can fail from vibration and heat cycling. Documented across US and AU Explorer owner forums. ATF loss from cooler line failure leads to transmission overheating and can cause shift quality deterioration and internal damage if not caught early.

What you would notice

  • Red ATF dripping under vehicle near transmission
  • ATF staining on transmission casing or underbody
  • Burning smell from transmission area
  • Transmission slip or harsh shifting if ATF level is low

How to check it

Where to look. Transmission cooler lines, fittings at transmission case and cooler

  1. Inspect transmission cooler lines at both the transmission case connection points and along their routing for cracks or wet fittings.

  2. Check ATF level and condition.

  3. Look for dried reddish-brown staining on the underside.

What it costs to put right

$300 to $900 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

Ask the seller

  • “Any ATF drips noticed under the vehicle?”
  • “Has the transmission been serviced recently?”
  • “Any transmission slipping or shift quality concerns?”

Now check the Ford Explorer you are actually looking at

Everything above is true of the model, and it is free. What it does not tell you is whether THIS car has been looked after: its odometer history and whether the reading has ever gone backwards, whether there is still money owing on it, whether it has been reported stolen, how many owners it has had and what it is really worth today. That comes from the official records for that plate. Enter the plate for the free details, or get the full history and a market valuation from $13.49.

Not sure what you would be paying for? See what a full KickTyres check includes.

Where this comes from

The failure described above is documented in published sources — owner forums, technical service bulletins, recall notices and workshop write-ups — held in our fault database. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them, and it is a starting point for an inspection rather than a manufacturer statement.

Ford Explorer buyer questions

Is u502 6f55 transmission cooler line leak serious on a Ford Explorer?

We rate it major and common on the Ford Explorer. The 6F55 six-speed automatic transmission in the U502 Explorer has documented cooler line fitting leaks at the transmission case connections. Quick-connect fittings and the line body itself can fail from vibration and heat cycling. Documented across US and AU Explorer owner forums. ATF loss from cooler line failure leads to transmission overheating and can cause shift quality deterioration and internal damage if not caught early.

How much does it cost to fix on a Ford Explorer?

$300 to $900 at New Zealand independent workshop rates. That figure is for this job on its own. A car showing the symptoms on this page is usually worth either walking away from or negotiating down by at least the repair figure.

Which Ford Explorer years are affected?

Our research records this fault on the 2011–2019 Ford Explorer. Build dates move around, especially on imported cars, so treat the range as the years to look hardest at rather than a guarantee either way. The official records tell you the exact build and first registration date for the car in front of you.

How do I check for it before I buy?

Inspect transmission cooler lines at both the transmission case connection points and along their routing for cracks or wet fittings. Check ATF level and condition. Look for dried reddish-brown staining on the underside. Look here: Transmission cooler lines, fittings at transmission case and cooler