6R140 Transmission Cooler Line Kit for 6.7L Powerstroke

If your 2011-2016 F-250, F-350, F-450 or F-550 with the 6.7L Power Stroke is weeping ATF at the transmission cooler lines, or the 6R140 pan temperature climbs every time you pull a grade with a trailer, this kit replaces the factory line assembly (Ford BC3P-7H420-BH) with two -8AN braided hoses. It is aimed at the owner who is tired of patching crimped rubber sections and wants a line set that can be torqued, re-tightened and serviced.

What the cooler lines do in a 6R140

The 6R140 sends converter-out fluid through an external cooler and back to the case for lubrication. Everything that heats the fluid, a slipping converter clutch, a loaded trailer, a long climb, has to be pulled out through those two lines. On the factory assembly the tubes push into bores in the case and are clamped by a bolted hold-down plate, while the cooler end uses quick-connect fittings. The weak points are the crimped rubber transitions, which harden from exhaust heat, and the hold-down joint, which Ford addressed in Special Service Message 46198 after leaks traced to tube and plate misalignment.

Symptoms that point to the cooler lines

• Fresh ATF behind the pan rail or down the bellhousing (case end) or on the frame rail near the radiator support (cooler end)
• Fluid level dropping between services with no internal symptoms
• Hardened, cracked or chafed rubber sections at the crimps
• Rising transmission temperatures when towing, once internal causes are ruled out
• Fluid smell after a long pull, with a wet line fitting underneath

How to confirm it is the lines before buying

Wipe both ends dry, run the truck to temperature and look for fresh seepage. A leak is easy to confirm. Overheating is not: an internal fault can cut cooler flow and look exactly like a line problem. A documented case in Gears Magazine found a 6R140 with cooler flow under a quarter of spec caused by a spun pump sleeve on a PTO-equipped unit, and Sonnax documents line pressure control bore wear that reduces cooler and converter flow from inside the valve body. If you have heat but no leak, run a cooler flow test first. Our 6R140 cooler line replacement guide walks through both connection types, and the 6R140 pump failure guide covers the internal side.

Fitment

This kit is listed for 2011-2016 Ford Super Duty trucks with the 6.7L Power Stroke diesel and the 6R140 TorqShift, as a replacement for line assembly BC3P-7H420-BH. It is not listed for the 6.2L gas trucks or for 2017-and-later Super Duty, which is a different chassis generation. Cab, bed and chassis-cab configurations can route differently, so compare the kit hose lengths (4.7 ft and 3.9 ft) to your factory lines, or send us your year and VIN and we will check it. Everything else for this unit is on our 6R140 parts page.

What is in the kit

• Two -8AN hoses, 4.7 ft and 3.9 ft, three-layer CPE construction with a stainless mesh layer under a nylon braid cover
• A billet case plate with two -8AN male fittings that mounts at the factory hold-down plate location
• Two billet -8AN adapters for the cooler end
• Four cushioned P-clamps, two hose separators and zip ties for routing

Install notes

• Drain the level down first. Opening a full system at the lines dumps fluid fast.
• Release the factory quick-connects with the correct 1/2 in. disconnect tool, not a screwdriver. A cracked fitting body turns this into a cooler job.
• Clean the case bores and plate face, seat the new plate square, and tighten the bolt evenly. Follow the kit torque values for the -8AN ends; do not overtighten aluminum fittings.
• Route along the factory path, clamp away from the exhaust and anything that moves, and use the separators so the hoses do not rub each other.
• Refill with Mercon LV only, cycle the selector, and set the final level hot. The larger hoses hold a little more fluid than the steel lines, so check again after the first heat cycle.

If the truck has been running hot for a while, the fluid has paid for it. Look at the 6R140 pressure control solenoid if you are seeing harsh or soft shifts, and the 6R140 shift kit if you are already into the valve body. The 6R140 problems and service guide covers what heat does to this unit over time.

Will this kit fit my 2017 or newer Super Duty?

It is listed for 2011-2016 Super Duty trucks with the 6.7L Power Stroke and 6R140, replacing factory assembly BC3P-7H420-BH. 2017 and later trucks are not on the listing. Send your year and VIN if you are unsure.

Does it fit the 6.2L gas Super Duty?

The kit is listed for the 6.7L diesel only. Gas trucks route the cooler lines differently, so it should not be assumed to fit.

What fluid do I use after installing the lines?

Mercon LV only. Ford Component Sales lists Mercon LV for the 6R140 with a total capacity of roughly 4 gallons. A line swap only loses part of that, so top off through the fill tube, cycle the gears and set the level hot.

My truck still runs hot after new lines. What else could it be?

Low cooler flow from inside the transmission. Documented causes include a spun pump sleeve on PTO-equipped units and line pressure control bore wear in the valve body. A cooler flow test separates a line problem from an internal one.

Do I need a relearn after replacing the cooler lines?

No. The lines are external plumbing and do not change any adaptive values. Refill with the correct fluid, set the level hot and recheck for leaks after the first drive.

What tool removes the factory quick-connect at the cooler?

A 1/2 in. Ford cooler line disconnect tool. Push the line in slightly, slide the tool into the fitting to release the locking tabs, then pull the line straight out.

• 6R140 Cooler Line Replacement Guide
• 6R140 Pump Failure Symptoms and Replacement
• 6R140 Pressure Control (EPC) Solenoid Symptoms
• Ford 6R140 TorqShift Problems and Service: A Rebuilder's Guide