On a 7.3 Powerstroke, the oil cooler “assemblies” (aka headers or mounts) aren't just end caps—they're the oil filter base, and the in/out for oil and coolant into the cooler. It’s also home to key pieces like the oil pressure regulator, oil filter bypass valve, and the block heater.

So when the assemblies get tired, it’s not just annoying seepage—it can turn into repeat leaks and a lot of wasted time.

Parts Links:

Riffraff Diesel Billet Oil Cooler Front Mount 94-03 F-Series 7.3L: https://www.riffraffdiesel.com/riffraff-diesel-billet-oil-cooler-front-mount-94-03-f-series-7-3l/

Riffraff Diesel Billet Oil Cooler/Filter Rear Assembly F-Series 94-03 7.3L: https://www.riffraffdiesel.com/riffraff-diesel-billet-oil-cooler-filter-rear-assembly-f-series-94-03-7-3l/

Riffraff Diesel Billet Oil Cooler Front Mount 94-03 E-Series 7.3L: https://www.riffraffdiesel.com/riffraff-diesel-billet-oil-cooler-front-mount-94-03-e-series-7-3l/

Riffraff Diesel Billet Oil Cooler/Filter Rear Assembly E-Series 94-03 7.3L: https://www.riffraffdiesel.com/riffraff-diesel-billet-oil-cooler-filter-rear-assembly-e-series-94-03-7-3l/

Oil Cooler 94-03: https://www.riffraffdiesel.com/oil-cooler-94-03/

Oil Cooler Assembly Bolt Kit 94-03 7.3L: https://www.riffraffdiesel.com/oil-cooler-assembly-bolt-kit-94-03-7-3l/

Oil Cooler Seal Kit 94-03: https://www.riffraffdiesel.com/oil-cooler-seal-kit-94-03/

Oil Filter 1994-2003 7.3L: https://www.riffraffdiesel.com/oil-filter-1994-2003-7-3l/

 

Why upgrade over the OE mounts

Most 7.3 oil cooler leaks start as O-ring failures at the assembly ends, allowing oil to seep where the cooler tube presses into the assembly. But here’s the part that drives people insane: even after replacing O-rings, leaks can come right back if the O-ring sealing regions are pitted/corroded. Often times assemblies (and even coolers) get replaced specifically because pitting in the sealing regions prevents a proper seal.

Plus, the factory assemblies are cast soft aluminum, and they can crack during removal/installation or while seating if you get aggressive.

 

What the Riffraff billet assemblies are

Our Billet Oil Cooler / Filter Rear Assembly is a robust replacement for the stock cast unit, designed for higher tolerances and better longevity than OEM.

• Hard Anodized 6061 aluminum (black or clear available)
• 100% Made in USA
• Filter adapter options: Motorcraft/Donaldson Blue style or CAT® 1R-1807

 

When it makes sense to install it

• You’ve resealed the oil cooler and it still weeps (common when the sealing surfaces are pitted).
• You find corrosion/pitting in the rear header sealing lands during teardown.
• You suspect a crack or damage in the cast header from age or prior work.

 

Install tips:

Remove the oil cooler unit (front and rear assemblies, and cooler); reassemble the whole unit with new mounts/assemblies, new cooler, new oil cooler O-rings; reinstall the whole thing as one with new assembly gaskets; then torque the oil cooler assembly bolts to 18 ft-lb and check for leaks.

Tip: If you’re resealing, use an OE-quality seal kit (we stock this one from Ford: https://www.riffraffdiesel.com/oil-cooler-seal-kit-94-03/).

 

Bottom line:

If you’re a 7.3 owner chasing repeat oil cooler leaks—or you’re rebuilding the cooler and want to eliminate the weak “cast rear header” variable—this billet rear assembly is the do-it-once solution.