A donut gasket is often used to seal a vehicle’s front exhaust pipe and manifold connection. However, there can be donut gaskets used in other locations downstream in the exhaust system of certain vehicles. The shape of the gasket resembles a donut and it seals the exhaust pipe that has a ball flared end.
1. Lift the vehicle all the way up on the car lift.
2. Put on the safety glasses and collect all the tools you need and place them in a handy location near you under the vehicle.
3. Determine if the front exhaust pipe is a Y-pipe. This would mean that it attaches to the engine at dual manifold locations on both the left and right side, then downstreams into a single chamber pipe. If this is the case, you will need to remove both front flange-to-manifold connections. If it is only a single-chambered pipe, you will only need to remove the single flange-to-manifold connection.
4. Set up the ratchet, extension and appropriate sized socket for the nuts on the manifold studs and make sure the ratchet is set in the reverse position.
5. Light the torch, choose one manifold stud nut to heat and heat it to a cherry red color. Quickly shut off the torch and apply the ratchet, extension, and socket to the nut and back it off the stud. If you feel any resistance, relight the torch and re-heat the nut some more so you do not break the stud.
6. Remove all the nuts from the manifold studs using this procedure. Take your time and be careful not to break any studs.
7. Put on the safety gloves and back the front pipe away from the manifold. Use the pry bar for leverage to help. In order to achieve this, you may have to remove some of the hangers downstream on the exhaust system to allow some movement and flexibility.
8. Allow the pipe and manifold to cool down some. Remove the old gasket and insert the new one.
9. Rethread or chase the manifold studs (once you’ve allowed them to cool) to clean the threads on them before replacing new nuts onto the studs.
10. Replace the nuts and tighten with the ratchet, extension, and socket.