Find solution

How Do I Remove a Broken Threaded Bolt From an Exhaust Manifold

The cast iron exhaust manifold is located on the side of the block under the valve cover. It removes hot exhaust fumes from the internal combustion process and funnels them into the exhaust system and out the tailpipe. Its fitted to the block on threaded studs. After removing it and taking apart the manifold sections, you may encounter a broken threaded bolt, due to rust and corrosion caused by extreme heat and high moisture conditions. The bolts must be extracted and replaced to prevent exhaust leaks containing dangerous levels of carbon monoxide that could enter the passenger compartment.

Instructions

1

Spray the broken bolt with penetrating oil using the red straw to direct the spray directly onto and around the bolt. Tap the bolt lightly to allow the oil to soak in around the threads. Let the bolt sit for a while. Respray a few more times and let it sit overnight if youre not in a hurry to remove it.

2

Grip the remnant of the broken bolt with a pair of vise grips or locking pliers if it sticks out above the manifold surface. Do not break it up any more if it wont come out. Grind it down smooth so its flush with the manifold face and is perpendicular to the drill bit youll be using to drill it out. Mark the center of the bolt with a punch. Try to get the punch mark in the exact center of the bolt.

3

Clamp the manifold securely to a drill press with a vise. You wont be able to hold it still by hand. Use a sharp, short drill bit as the bolts are harder than the manifold. Adjust the chuck so its close to the manifold to cut down on free play and flex in the drill.

4

Put on safety glasses and direct a strong light at the broken bolt. Drill carefully into the center of the broken bolt using the punch mark as a guide. Do not force the drill in an attempt to drill out the bolt in one stroke. Back the bit out several times to clean metal shavings out of the drilled hole. Be careful not to let the drill seek its own path alongside the bolt and ruin the threads.

5

Clean out and reuse the original threads with a new bolt after removing the metal from the old bolt. Take one of the good bolts to the parts dealer to match it exactly. Replace any of the old bolts that are rusted or corroded to prevent them from breaking and allowing exhaust fumes to escape into the engine compartment.

Posted by Unknown at 5:45 AM

Email ThisBlogThis!Share to TwitterShare to FacebookShare to Pinterest

Labels: a, an, bolt, broken, do, exhaust, from, how, i, manifold, remove, threaded