If you are pulling a radiator, flushing a cooler or dropping the transmission on a 2003-and-newer Ford Explorer with the 5R55W or a Super Duty with the 4R100, the first wall you hit is the quick-connect fitting on each cooler line. A pick or screwdriver tends to crack the plastic retainer and gouge the tube, and then a simple job turns into a leaking line. The OTC 6593 set gives you the two correct sizes to release those fittings cleanly: a 3/8 inch tool for the Explorer lines and a 1/2 inch tool for the Super Duty lines.
What this tool does on a 5R55W Explorer or 4R100 Super Duty
Ford's push-on cooler fittings hold the steel line with internal locking fingers. The line only comes out when those fingers are spread evenly all the way around. Each OTC tool is a split collar: you snap it over the cooler line, slide it along the tube and push it squarely into the fitting. That spreads the fingers, and the line pulls free without bending the tube or chewing the retainer. The 3/8 inch piece is listed as similar to Ford special tool 307-441 and the 1/2 inch piece as similar to Ford 307-459, so they do the job the dealer tools do.
Jobs where you need it
- Replacing a leaking radiator or the transmission cooler built into it
- Backflushing the cooler and lines after a rebuild or a burnt-clutch failure
- Removing the transmission, where the lines must come off at the case or the radiator end
- Replacing a weeping cooler line or a fitting with a hardened O-ring
- Installing an auxiliary cooler or a cooler line kit for towing
Know what you are disconnecting first
This set only works on push-to-connect style fittings in its two sizes. It does nothing for banjo bolts or threaded tube nuts. Our E4OD cooler line replacement guide explains why: across the E4OD and 4R100 run, the fittings were not the same every year, with banjo fittings and crush washers on some trucks and quick-connect collars with internal O-rings on later production. Look at both ends of the line before you start. If you are chasing low cooler flow or a converter that runs hot, the cause may be inside the pump rather than at the line, and the E4OD common problems guide walks through the line-to-lube regulator valve and flow issues that look like a cooler problem.
Fitment
Per the tool's own application list: the 3/8 inch disconnect is used on 2003 and newer Ford Explorers with the 5R55W transmission, and the 1/2 inch disconnect is used on 2003 and newer Ford Super Duty trucks with the 4R100. Many other Ford trucks and SUVs use the same fitting sizes, but measure your line outside diameter before relying on that. Older E4OD trucks with banjo fittings will not need it. Parts for these trucks are on our E4OD and 4R100 parts page and our 5R55 transmission parts page.
Using it and putting the line back
- Clean the fitting and the tube first. Packed road grit keeps the collar from seating, and grit pushed into an open fitting ends up in the cooler circuit.
- Snap the correct size around the line, push it fully into the fitting, hold it there and pull the line straight out. Do not twist the tool to pry the fitting.
- Have a drain pan ready. The cooler lines hold fluid and will drain when opened.
- Inspect the O-ring and retainer before reconnecting, and replace any that are cut or hard. The line should click in and stay put when you tug it.
- Ford's 5R55W/S service procedure calls for cleaning and backflushing the cooler and lines after a rebuild, with the cleaner pressure line on the return line (the longest line), and replacing the cooler when the transmission has been disassembled for new parts.
- Top off with the correct fluid when you are done: Mercon V on these trucks. Working on the transmission itself? Our 4R100 bushing driver kit and E4OD pump are common next steps.
