The Ford Motorcraft F4TZ-6A636-A (F4TZ6A636A) is a genuine OEM front oil cooler mounting gasket engineered specifically for 1994–2003 Ford F-250, F-350, F-450, and F-550 Super Duty and OBS trucks, 2000–2003 Ford Excursions, and 1994.5–2003 Ford E-Series vans equipped with the 7.3L Powerstroke diesel engine. Installed between the forward cast-aluminum oil cooler header and the driver-side front engine block mounting pad (just behind the water pump and timing cover), this precision-stamped composite gasket creates an airtight, leak-free seal across the engine oil and coolant crossover passages. Built from oil- and coolant-resistant high-density gasket material to exact Ford engineering specifications, it maintains clamping torque and dimensional integrity under heavy thermal expansion and hydraulic oil pressure spikes.

External coolant puddles beneath the front driver-side axle, engine oil dripping onto the front differential and crossmember, loss of engine oil pressure from gasket blowout, and fluid weeping caused by degraded paper or flattened aftermarket gaskets are what this genuine replacement gasket cures. The front oil cooler header simultaneously channels pressurized engine oil into the block and routes engine coolant through the heat exchanger bundle. Inferior aftermarket gaskets frequently saturate, swell, or rupture under constant thermal cycling, leading to messy leaks or internal fluid crossover. Installing the authentic Ford F4TZ-6A636-A ensures exact bolt-hole alignment, precise fluid passage cutouts, and uniform crush resistance to maintain a permanent seal. It is a single OEM front oil cooler-to-block mounting gasket; the rear header gasket (F7TZ-6A636-AAA), inner silicone O-rings, and oil cooler bundle are sold separately.

It fits all 1994–1997 Ford OBS and 1999–2003 Ford Super Duty F-250, F-350, F-450, and F-550 trucks, 2000–2003 Ford Excursions, and 1994.5–2003 Ford E-250, E-350, and E-450 Econoline vans equipped with the 7.3L Powerstroke turbo diesel engine.

Fitment

• 1994–1997 Ford F-250 / F-350 7.3L Powerstroke Turbo Diesel (OBS)
• 1999–2003 Ford F-250 / F-350 / F-450 / F-550 Super Duty 7.3L Powerstroke Turbo Diesel
• 2000–2003 Ford Excursion 7.3L Powerstroke Turbo Diesel
• 1994.5–2003 Ford E-250 / E-350 / E-450 Econoline Van 7.3L Powerstroke Turbo Diesel
• Genuine Ford OEM replacement gasket guarantees exact port alignment and sealing
• Engineered to withstand high-pressure engine oil feed and pressurized engine coolant
• Constructed from high-density, heat- and chemical-resistant composite material
• Driver-side front oil cooler header-to-engine block mounting location
• Direct replacement for original factory part number F4TZ-6A636-A
• Eliminates chronic coolant and oil leaks along the front driver-side engine block rail
• Individual front oil cooler header mounting gasket (sold individually)

Position a large drain pan underneath the front driver side of the engine, open the radiator drain valve, and completely drain the engine coolant; drain the crankcase oil as well if rebuilding the complete cooler assembly. Unbolt the three rear oil filter header bolts from the block, remove the front header-to-block mounting bolts, and lower the entire oil cooler assembly out from under the vehicle. Scrape away the old front gasket and thoroughly clean the engine block mounting pad and the cast aluminum front header mating face using a plastic scraper and brake cleaner until the surfaces are completely dry, flat, and free of residual gasket material or oil film. Position the dry Ford F4TZ-6A636-A gasket onto the front block mounting pad (install clean and dry; do not apply RTV silicone, as excess sealant can squeeze into narrow oil passages and starve critical bearings). Align the rebuilt oil cooler assembly against the engine block, start all mounting bolts by hand to ensure square alignment, and torque the front header-to-block bolts in an alternating sequence to 18 ft-lbs (24 Nm). Torque the rear header bolts to 18 ft-lbs, refill the crankcase with 15W-40 diesel oil, fill and bleed the cooling system with a 50/50 diesel coolant mix, and run the engine to verify zero oil or coolant leaks at the front mounting interface.