Part two of our series forced us to tackle a job many 7.3L Power Stroke owners dread: replacing the exhaust manifold up-pipes. While it’s not a fun process, it’s a necessary one as these engines age. At some point, every 7.3L requires attention in this hard-to-reach, back-of-the-engine area. What Happens The exhaust up-pipes were designed using a crush donut gasket, which seals the top of each pipe to the turbocharger’s Y-collector. After thousands of engine heating cycles, the expansion and contraction of the exhaust leads to leaking donut gaskets. The result is an exhaust leak that can cause dismal performance, increased EGT, and a mess of soot all over the back of the engine, firewall, and transmission. Ways To Simplify The Job Pulling the transmission will allow you plenty of access to the back of the engineand if you’re working on a ’94 to ’97 Ford, it’s pretty much a necessity. Getting the truck on a lift also simplifies the job, and we lucked out by having the Ford specialists at Flynn’s Shop give us both a lift and a helping hand. To ease your labor efforts, soak every bolt you’ll be removing with a penetrating lubricant. Finally, know that the job requires time and patience. Expect to fight rusted, brittle, and seized up nuts and bolts throughout the process. The payoff will be an engine free of exhaust leaks for another 15 years. Stay tuned, because next month we’ll be installing our bulletproofed E4OD and a new flexplate and taking the truck for its first testdrive with all the newfound power. Part 2, 7.3L Power Stroke Parts List: Part: Ford Part Number: Price: Qty: Up-pipe (left) PN F4TZ-6K854-A $97.59 1 Up-pipe (right) PN F6TZ-6K854-A $47.39 1 Up-pipe Donut Gaskets PN F4TZ-6K854-C $8.68/each 2 Up-Pipe Flange Bolts (bottom) PN W300013 $2.17/each 4 Up-Pipe Flange Nuts (bottom) PN W300050 $3.88/each 4 Up-Pipe Flange Bolts (top) PN W301640 $3.83/each 4 Turbo Pedestal O-ring (small) PN F4TZ-6N653-A $2.37 1 Turbo Pedestal O-ring (large) PN F4TZ-6N653-B $2.42 1 Turbo Exhaust Inlet Gasket PN F4TZ-6N640-B $6.88 1 Turbo Exhaust Y-Collector (optional) PN F4TZ-6K854-D $118.15 1 Total Price: $213.53 to $331.68 (with Y-Collector) *Mention this Diesel Power article to get these prices from Rodeo Ford This is the basic hardware needed to tackle an up-pipe replacement on a ’94 to ’97 7.3L Power Stroke, although replacing the Y-collector is optional. For Super Duty 7.3Ls (’99 to ’03), International offers up-pipes with bellows as an option (PN 1837872C93). The up-pipes with bellows rule out the biggest weak link since they don’t utilize donut gaskets to seal the up-pipes to the Y-collector. All of our genuine Ford parts came from Rodeo Ford in Goodyear, Arizona. Removing the transmission from the vehicle (ours was being rebuilt and beefed up at the time) is the easiest way to perform the job on a ’94½ to ’97 truck (the job can be accomplished much easier by working on top of a ’99 to ’03 Super Duty engine rather than on the older Fords). The task does call for removing the turbo from the engine, so you’ll want to pick up a turbo flange gasket and some turbo pedestal O-rings. Removing the transmission from the vehicle (ours was being rebuilt and beefed up at the ti Here you can see the passenger-side exhaust leak, which had started to accumulate soot at the top of the up-pipe. We caught it before the leak had a chance to hamper our truck’s performance, fuel economy, and exhaust gas temperature. With our hybrid injectors now installed, this problem would’ve gotten worse and could’ve hampered our dyno and boost numbers if left alone. Here you can see the passenger-side exhaust leak, which had started to accumulate soot at This should give you an idea of what your factory hardware will look like with the nut and washer seized to the bolt. We had to cut this bolt in half to get it out of its respective pipe flange. Expect to replace all hardware, as some bolts will strip and most bolt heads will round off during removal. We got our Grade 10.9 up-pipe bolts from Ford. This should give you an idea of what your factory hardware will look like with the nut and Of the bottom four nuts and bolts connecting the up-pipes to the exhaust manifolds, only one loosened without having to be cut in half. If you are fortunate enough to be able to loosen all of them, a 13mm socket (for the nuts) and a 10mm wrench (for the bolts) will be all you need. Of the bottom four nuts and bolts connecting the up-pipes to the exhaust manifolds, only o Once the up-pipes were free from the exhaust manifolds, the entire assembly (still bolted to the Y-collector) was finagled under the firewall, and off the engine. Once the up-pipes were free from the exhaust manifolds, the entire assembly (still bolted Using new fasteners is essential with this job (as is antiseize if you ever have to take it apart again). If you plan to retain your old Y-collector (we replaced ours), it would be wise to place it in a vise in order to remove the top up-pipe bolts. For kicks, Chad Flynn of Flynn’s Shop showed us how to remove them, but it called for hammering a 3⁄8-inch socket onto the 10mm bolt heads to make it happen. Using new fasteners is essential with this job (as is antiseize if you ever have to take i If you look close, you can see that the bad donut gasket allowed the passenger-side up-pipe to walk around inside the pipe flange, wearing into the up-pipe. Although you can choose to just replace the exhaust’s donut gaskets, we recommend replacing the exhaust up-pipes while you have everything apart. If you look close, you can see that the bad donut gasket allowed the passenger-side up-pip Here is the passenger-side replacement pipe from International. In order to reuse the pipe flanges, the bellowed end had to be cut off the top of the stock up-pipes. Flynn tapped the flanges onto the new up-pipes with a hammer. Here is the passenger-side replacement pipe from International. In order to reuse the pipe Flynn first installed the new up-pipes on the new Y-collector and attached the bottom of the up-pipes to the exhaust manifolds without tightening the fasteners. Then he reinstalled the turbo and pedestal assembly and connected the Y-collector to the turbo’s exhaust inlet flange. Flynn first installed the new up-pipes on the new Y-collector and attached the bottom of t With the assembly secured to the turbo, Flynn connected the bottom of the up-pipes to each exhaust manifold and began snugging up every fastener. Then everything was tightened and the new donut gaskets were squished between the Y-collector inlets and the pipe flanges for a good seal. Note: The up-pipe-to-exhaust-manifold bolts call for 19 ft-lb, and the up-pipe to Y-collector bolts call for a 21 ft-lb torque spec. With the assembly secured to the turbo, Flynn connected the bottom of the up-pipes to each The finished product looked like this. Much like the donut gaskets up top, the bellows on the bottom of each new up-pipe were crushed tightly where they meet the exhaust manifolds for the ultimate seal. The finished product looked like this. Much like the donut gaskets up top, the bellows on SOURCES Flynn's Shop Alexander IL 217-478-3811 Rodeo Ford 1788 Saamis Drive NW Medicine Hat, Alberta Medicine Hat, Alberta Canada T1C1W7 1-877-910-7788 www.rodeoford.com By Mike McGlothlin Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!