7.3L Power Stroke Up-pipe Gasket Replacement

7.3L Power Stroke Up-pipe Donut/Seal Repair

A low boost condition on the 7.3L Power Stroke can be caused by a number of problems, including a leak on the compressor side of the turbo plumbing, a leak on the exhaust side of the turbo, or a combination of both. Leaks on both the air and exhaust sides of the turbocharger commonly develop over time. On the exhaust side, it is typical and completely normal for the exhaust gaskets to deteriorate and leak at the pair of joints that connect the individual up-pipes to the up-pipe collector, which is attached to the inlet of the turbocharger turbine housing. When this occurs, exhaust pressure across the turbine is reduced and overall performance can be critically affected. A leaking up-pipe seal can be distinguished by visible build up of exhaust soot around the up-pipe collector flanges and, in extreme cases, on the firewall in the vicinity of the up-pipe connections.

Applicable Model Years: 1999.5 - 2003 Ford Super Duty, 7.3L Power Stroke Diesel
Up-pipe donut gaskets/seals: Ford F4TZ-6K854-C (sold individually)
GT38 turbocharger reinstall kit*: Ford F81Z-6N653-BA (International 1831658C91, Alliant Power AP63461)
Turbo to up-pipe collector clamp: Ford F81Z-8287E-A
Compressor to intake "spider" plenum clamp: Ford 1831214C1

Click any thumbnail image to view high resolution fullsize

Inner fender removal

• Disconnect both negative battery cables.

• Remove plastic "Power Stroke" engine cover (if applicable).

• Remove passenger side inner fender (various fasteners requiring 5/16" and 3/16" sockets). You will need to disconnect and set aside anything mounted to or supported by the inner fender, i.e. 4 wheel drive vacuum lines.

Intercooler tube disconnected

• Loosen clamps and disconnect intercooler tubes from the intake "spider" plenum. You do not need to remove the intercooler tubes completely, although it does leave more room to work if they are removed.

Plenum closeup

• Remove air intake heater (AIH) wire leads (pair of lug connectors).

• Disconnect intake air temperature (IAT) sensor connector.

• Disconnect manifold absolute pressure (MAP) sensor supply line.

• Disconnect wastegate pressure lines from wastegate solenoid and intake plenum.

• Remove wastegate solenoid from intake plenum (8 mm socket).

Wastegate actuator closeup

• Disconnect wastegate pressure line from wastegate actuator mounted near the rear of the turbocharger on the compressor side.

• Remove intake tubing between air filter box and turbocharger inlet.

All sensors and lines removed from plenum

• The intake plenum should not have any wires, hoses, or connections attached to it at this point.

• Loosen the intake boots at the outlets of the intake plenum that feed into the intake manifolds at each bank of the engine.

Plenum to turbocharger clamp

• Generously loosen the marmon clamp connecting the intake plenum to the turbocharger compressor outlet.

• Loosen the clamps attaching the intake manifold boots to the intake plenum on each bank.

Removing intake plenum

• Pull the intake plenum outwards to break the seal between it and the turbocharger, then pull the plenum upwards to remove from the engine. There is an o-ring seal between the plenum and turbocharger - discard it, this does not get reused.

• Cover the now exposed intake manifold openings on each bank with clean rags to keep debris out.

Removing exhaust downpipe

• Generously loosen the marmon clamp attaching the exhaust downpipe to the turbocharger turbine outlet. Disconnect the downpipe from the turbocharger and allow it to hang freely.

• From beneath the truck, separate the downpipe from the exhaust system, then completely remove the downpipe. Separating the downpipe from the exhaust system may prove difficult - penetrating oil, patience, and a dead blow hammer will make matters easier.

Disconnecting EBPV linkage from turbo

• Disconnect the exhaust backpressure valve (EBPV) linkage from the turbocharger. To do so, locate the small sliding clip on the bottom of the link. Slide the clip towards the driver's side to disconnect. The linkage does not get completely removed at this point.

Removing exhaust up pipe collector clamp

• Locate and remove the marmon clamp connecting the exhaust "Y" collector to the turbocharger turbine inlet. Once the clamp is loosened, you will need to pry the clamp off with a screwdriver - these have a tendency to stick.

Turbocharger to pedestal mounting bolts

• Remove the two turbocharger mounting bolts located between the compressor and turbine housings.

Removing turbocharger

• Position the turbocharger forward until it releases from the exhaust "Y" collector, then guide the EBPV linkage off of the backpressure valve swing arm as you lift the turbocharger upwards slightly.

• Carefully remove the turbocharger from the vehicle. The turbocharger is heavy and can be awkward to guide out of the engine - be patient and maneuver cautiously.

Automatic transmission dipstick tube

• Remove the bolt holding the transmission fluid dipstick against the engine block (passenger side rear of engine block, automatic transmission applications only). This improves access to the rear exhaust collector bolt on the passenger side.

Passenger side difficult to reach collector bolt

• All collector bolts require a 10 mm socket - a deep socket is not necessary and may actually cause greater interference than a shallow socket.

• The passenger side rear collector bolt is the most difficult to access and as such we suggest removing it first. You will need somewhere in the ballpark of 26 inches of total extension to reach the bolt. It is inaccessible from under the hood, so you'll need to position your socket/extensions between the firewall and passenger side exhaust up pipe, positioned between the engine block and the transmission dipstick (automatic transmission only), coming in through the passenger side fender well. See series of fullsize images for clarification.

Driver side collector bolts

• The passenger side front "Y" collector bolt is accessible from under the hood using a 10 mm wrench.

• The driver side rear "Y" collector bolt is accessible from underneath the truck. You will once again need around 26 inches of extension to reach the bolt. It is not particularly difficult to reach, although a second pair of hands is helpful in aligning the socket from under the hood.

• The drive side front "Y" collector bolt is accessible from underneath the truck or from under the hood. It is not particularly difficult to access.

Exhaust Y collector removed

• Discard (do not reuse) the collector bolts and remove the "Y" collector. You may need to rock the collector side-to-side as you apply force upwards to remove it.

• Remove and replace the exhaust donut gaskets. If the up pipes are damaged or kinked where the collector sits, they are likely to leak again and should be replaced or repaired. An exhaust expander can be used to expand pipes that are misshapen.

Exhaust Y collector installed with new gaskets

• Reinstall the "Y" collector and hand tighten all bolts. Do not reuse the hardware! Always use new collector bolts. You may wish to apply a small amount of anti-seize on the bolt threads prior to installation. The collector should be loose enough to rock side-to-side at this point.

• Position the collector marmon clamp onto the exhaust "Y" collector. Make sure it is loose enough to maneuver slightly so that it can be aligned with the turbocharger.

• Notice the small extruded pin cast into the top of the "Y" collector where it mounts to the turbocharger. This must align with the corresponding indentation in the turbocharger turbine inlet during re-installation.

Replacing turbo pedestal o-rings

• Replace the pair of turbocharger pedestal o-rings - these are not to be reused. Lightly lubricate them with clean engine oil prior to installation.

• Install a new marmon clamp on the exhaust "Y" collector loosely as not to interfere with turbocharger re-installation.

• It is recommended to replace the EBPV linkage clip with a new one, as supplied in the turbocharger reinstall kit (Diesel O-rings part # 14-009), before reinstalling the turbo.

• Reinstall the turbocharger onto the turbo pedestal, line up and reinstall the EBPV linkage. Also ensure that the indentation on the turbocharger turbine is properly aligned with the "Y" collector alignment pin, then install the turbocharger to pedestal bolts hand tight.

• Torque turbocharger pedestal bolts to 18 ft-lbs.

Reinstalling turbocharger

• Align, tighten, then torque the exhaust collector to turbine marmon clamp to 60 in-lbs.

• Torque all "Y" collector bolts to 21 ft-lbs, then torque them again.

• Reinstall transmission dipstick to engine block retaining bolt (automatic transmission, if previously removed).

• Reinstall the exhaust downpipe, torque marmon clamp at turbine outlet to to 60 in-lbs.

• Remove any rags in the intake manifold openings, then reinstall the intake manifold plenum using a new o-ring seal between the plenum and turbocharger. Lightly lube the new o-ring with clean engine oil.

• Tighten intake plenum to turbocharger clamp - snug, do not over-tighten.

• Tighten intake manifold to intake plenum boots.

• Reinstall intercooler tubes to the intake plenum, tighten all clamps.

• Reinstall remaining sensors, intake tubing, and wastegate actuator lines.

• Reinstall inner fender, reconnect negative battery cables.