GASKETS & SEALS

Gaskets & Seals For Peterbilt Trucks

Gaskets and seals are responsible for keeping oil, coolant, fuel, air, and exhaust where they belong in a Peterbilt's engine and drivetrain. A failed gasket or worn seal leads to fluid loss, contamination, and in the case of exhaust leaks, potential safety hazards from carbon monoxide intrusion into the cab. We carry engine gaskets, valve cover gaskets, exhaust manifold gaskets, crankshaft seals, axle seals, and transmission seals for Peterbilt trucks and their common drivetrain components.

Frequently asked questions about gaskets & seals

How do I find a slow oil leak on a Peterbilt engine?

Start by cleaning the engine thoroughly with degreaser and running it to operating temperature, then inspect for fresh oil seepage. Common leak sources on Class 8 diesels include the valve cover gaskets, front and rear crankshaft seals, oil cooler gaskets, and the oil pan rail. Fluorescent leak detection dye added to the oil and a UV light can help pinpoint a slow seep that's hard to trace visually. Address any seep before it becomes a drip — leaking oil onto hot exhaust components is a fire risk.

What causes exhaust manifold gaskets to fail on a diesel truck?

Exhaust manifold gaskets are subjected to extreme thermal cycling — they expand and contract thousands of times across an engine's service life. On turbocharged diesel engines, the manifold operates at very high temperatures, which accelerates gasket degradation. Warped manifolds from overheating events are a common cause of premature gasket failure, so always check the manifold sealing surface for flatness before installing a new gasket. A blown exhaust manifold gasket typically produces a distinctive ticking or hissing sound that's most noticeable at cold start.

Can I reuse gaskets when reassembling engine components?

Generally no. Most gaskets are designed for single use — the compression and sealing process deforms the material, and a reused gasket is unlikely to seal as reliably as a new one. Exceptions include some metal shim-style gaskets that can be reused if undamaged, but as a rule, new gaskets should be used any time a sealed joint is opened. The cost of a new gasket is negligible compared to the labor of redoing a job because of a sealing failure.

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