Tip & How-To about Cars & Trucks

Drill out corroded pipe/studs

A backyard machine shop technique I used recently worked perfectly on a piece of brass pipe corroded into a cast iron steam radiator, but the procedure is labor intensive. Use a hand electric drill or a drill press to drill a small hole reasonably centered. Perfect centering is not desirable, as you shall see below. Then drill the hole out with progressively larger drills, shifting to 1/64th " increments in drill size as you approach the threads. If you have complete letter and fractional drill sets you can get less than 1/64th" increments for some steps. Clean the hole well and inspect carefully for signs of the threads showing up after each increment of drilling. Stop drilling as soon as you can see any sign of threads.

At this point, it's difficult to peck the remnant of the stud loose from the threads with a sharp punch because it still resists collapsing inward due to the full circles remaining in the threads. To make it collapse easier, use a triangular needle file to file two longitudinal grooves in the thicker side of the remnant until the thread barely shows at the bottom of each groove. The two grooves should be about 30 to 40 degrees apart on the thick side of the remnant.

Now use your sharp punch to knock the section between the two notches inward from the threads. The strength of the thicker metal left due to imperfect centering of the drilled hole is actually beneficial here because the piece will be strong enough to come loose as a single piece, rather than just the top thread breaking loose. Last time I did this (a week ago) I was able to grab the section knocked inward with needle nose pliers and pull the whole remnant out with a twist.

Depending upon your finesse, this can leave a thread essentially undamaged except for a small divot at the point you punched. Run a tap down the hole to clean out the corrosion and clean up any damage done. Strength of the threads should be unaffected unless you were really clumsy.

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water is evaporating every two day, what do I do?

You need to start with a simple test on the radiator system. Most big autoparts stores have tool loaner programs and you can borrow a radiator tester to check for other problems. These problems would be a bad cylinder head gasket or cylinder head to mention a few.

By using the test tool I mention, you can discover if the system is losing pressure internally once it is pressurized. If you have a V-6 or V-8 type engine, you do not have to remove both cylinder heads to repair only one. Just look at the sparkplugs for unusual coloration.

There is every probability the excess water is flowing through the exhaust pipe in the form of steam, or the radiator is seeping slowly enough to let the water evaporate before hitting the ground.

If you do not want to do this yourself, a Radiator repair place can test this for you. Some places may not want to disassemble the engine, but a Dealer can do it. A general repair shop can also do it if they do engine work.

Some people use additives to plug the water leak. The best additives are usually $15 and up and require immediate flushing after they have been added to the system. Modern chemicals should be matched to modern engines because the older engines did not have aluminum or exotic metal blends, they were just durable cast-iron. The older chemicals may be too caustic for a modern engine or ineffective for aluminum components.

I hope my solution is helpful.

May 14, 2012 | 2003 Ford Explorer

2 Answers

how to disassemble cast iron radiator

Here's how to they're assembled - disassembly is the reverse:

You'll need Adobe Reader to view the PDF file pointed to by this link.

The Radiator Spud Wrench below may prove useful, but it's a plumbing specialty tool that a licensed master plumber would have.


Nov 27, 2011 | Cars & Trucks

2 Answers

water is not flowing through system causing it to overheat. new thermostat, new water pump. What next.

It sounds as thought it could be a clogged radiator. Have it checked out by a radiator repair shop. It may be necessary to remove radiator from vehicle if unable to drive.

Jun 15, 2010 | 1997 Mercury Cougar XR7

4 Answers

if I cannot find a replacement exhause manifold for 1950 ford f1 239 engine is it possible to repair most cracks

take it to a machine or welding shop depending on damage cast can be welded need to be done right or cast becomes brittle --look in hemmings the auto everything book and look up online or local for ford clubs their members usually can help

Oct 28, 2009 | Ford F Cars & Trucks

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