How to Repair a Flex Pipe Exhaust

Flex pipes look unique compared to other exhaust pipes because they are covered with braided steel. They are an essential part in a front-wheel or all-wheel drive motor vehicle's exhaust manifold. The flex pipe connects immovable parts of the exhaust system, and without it, these other parts would snap and break. There is always the option to replace a broken flex pipe; however repairing one involves just a little know-how and some basic parts.

Diagnose a Broken Flex Pipe

Flex pipes can break from basic wear and tear or from damage accrued from bottoming a car out on a bump in the road. It is obvious when the pipe breaks because the car sounds as if there is no exhaust system and it gets very loud. Before purchasing any parts, always take a look under the car to make sure the problem is the flex pipe, and not the solid exhaust pipes. If it is the flex pipe, rips are visible in the outer braided mesh of the pipe.

Gather Supplies

The parts and tools necessary to repair a flex pipe are not expensive, and far cheaper than replacing the pipe with a brand new one.

· Exhaust heat shield

· Tail pipe bandage

· Tail pipe sealer

· Two exhaust clamps

· Axle stands

It is very dangerous to work underneath a car that is only held up with jacks. Lift the vehicle up with a jack, and then set an axle stand on each side of the car to be safe. Additionally, only perform this repair on level ground.

Repairing a Flex Pipe Exhaust

After the car is resting on axle stands, let the car run for a few minutes to determine the only damage is to the flex pipe. Sometimes there are small cracks in other parts of the exhaust as well. If this is the case, the project entails a lot more work and it might make sense to let a professional mechanic work on it.

Wrap the Flex Pipe

If the only damage is to the flex pipe, take the tail pipe bandage and wrap it around the flex pipe from end to end. Most professionals recommend wrapping it in two to three layers, but never more than this. Wrap the bandage as tightly as possible and make it neat to improve the longevity of the repair.

Once the wrapping is complete, generously apply exhaust sealer to both ends of the wrap. The sealer keeps the bandage from unwrapping. Allow a few minutes for the sealer to completely set before moving on to the next step.

Cover the Bandage with Exhaust Heat Shield

Exhaust heat shield is an aluminum wrapping designed to withstand the high heat exhaust systems produce. Wrap the shield over the bandage and hold it in place. It is fine if the shield is a little longer than the flex pipe.

Next, attach an exhaust clamp on each end of the heat shield. Depending on the type of clamp, a screwdriver or small wrench may be necessary to tighten them. Make sure to get clamps that fit the diameter of the flex pipe.

Test the Repair

To make sure the heat shield and bandage stay in place, start the car and let it idle for 10 minutes, checking on the repair every few minutes. If the repair is successful, reap the benefits by driving a less noisy car.

People sometimes pass car inspections with this type of repair, but some states may require a whole new flex pipe before receiving next year's sticker. Again, this is more costly and usually involves welding, so it is a job better left to professionals.