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Changing a Turbo to Exhaust Manifold Gasket on a Cummins Mid-Range Engine

The pics attached show what we have developed over the years as the “Seaboard Way” to changing out the manifold cap or turbo gasket.

Although this is the manifold cap, all is exactly the same for the turbo as to HOW it should be done…

Turbo gasket is # 3921926, unless you have real crappy surfaces… Then, we use a “composite gasket”…

All pieces need to be CLEAN & Smooth–Studs need to be pulled and wire brushed or REPLACED (cheap insurance)… I always replace the nuts with the newer SS series (17-4 PH) and lube all with Rector-Seal #5… You’ll need a GOOD 15 MM box wrench to tighten if it’s the turbo gasket replacement… Nothing else will fit in the confined area.

Don’t try and re-invent anything on the install (I’ve already done that) –The pics show it, all based on doing this since 1986-ish, and never an issue… I wish I could say the same for the “book method”…

The gasket IS NOT Murphy proof – Coolant Passages: Remember “Big holes to Big holes” and, “Little holes to little holes”… Also, see the letters on the gasket “Turbo Side”??

Install the exhaust elbow/riser onto the turbo with a gasket. There are now two gasket options available: The OEM metal gasket, which doesn’t do much unless the surfaces are perfect (In fact, some people just threw those out and used RTV in the old days), and now we have the graphite gaskets available, which are ideal if the turbo or exhaust has any imperfections or pitting. The graphite gaskets should be installed dry. If you cannot get a seal you can try to use a bead of high-temp silicone. If the turbo face has pitting or imperfections it can be resurfaced by hand with a large flat sanding block made of aluminum or oak.

Put high temp anti seize on the turbo to exhaust bolts as grease will just turn to smoke in this location. 

Good wrenching…

Changing a Turbo to Exhaust Manifold Gasket on a Cummins Mid-Range Engine

Be sure to drain coolant before attempting the turbo or cap gasket replacement.
Be sure to drain coolant before attempting the turbo or cap gasket replacement.
Parts that will be used in this job.
Parts that will be used in this job.
Insert studs
Insert studs
Be sure to lubricate studs at both ends with Rector Seal so you can make the proper torque.
Be sure to lubricate studs at both ends with Rector Seal so you can make the proper torque.
Thoughly coat the edges of the gasket with a light smear RED RTV around all passages.
Thoughly coat the edges of the gasket with a light smear RED RTV around all passages.
Remember, small holes to small holes and large holes to large holes. It is possible to flip the gasket the wrong way which will result in serious leakage
Remember, small holes to small holes and large holes to large holes.
It is possible to flip the gasket the wrong way which will result in serious leakage

Manifold7

The completed job, cap in place.
The completed job, cap in place.