Car repair is far from the easiest process, and it doesn’t matter what brand the car is and what year it is manufactured. All cars are subjected to serious loads every day, which means that breakdowns are inevitable. An ordinary motorist can easily fix most of these malfunctions in garage conditions, working slowly and accurately. If you show negligence in matters of car repair, you can often complicate the situation.
It so happens that during repair work, the thread breaks when tightening or loosening bolts and studs. This is very unpleasant, especially if there is no knowledge on how to unscrew a broken hairpin. This situation baffles any repairs. Let's try to figure out how to get out of this unpleasant situation.
Often fasteners break if the master is large and has great physical strength, and the stud is stuck or rusted to the thread. This is not about those machines that have just left the assembly lines. Very often, owners of old cars are faced with similar problems, which were stored and operated carelessly. And more specifically, most likely such a machine was stored in places with high humidity. Parts of the chassis — studs of
wheels, hubs — are almost constantly in contact with water
. Therefore, it is not surprising that these elements rust. As a result, the owner asks how to unscrew the broken hairpin from the hub.
However, the fasteners do not twist and break not only due to moisture, but also due to high temperatures. For example, the exhaust manifold can be heated up to 400 degrees. As a result of exposure to high temperatures for a long time, the stud corrodes.
How do studs break?
These fasteners can break in different ways. The most unpleasant situation is when they are literally cut off flush. Then the master has to think about how to unscrew the broken hairpin, because without the use of special tools and technologies in this case can not do.
It is much better if the part breaks down already at the exit from the thread, when a small part of its “body” is visible and remains on the surface. In this case, if the bolt is already broken, it will turn out, and it can be affected by pliers, screwdrivers and welding.
Effective ways to deal with broken bolts and studs
Professional locksmiths know several effective methods on how to unscrew a broken hairpin. Before embarking on this business, it is necessary to prepare. By these works you need to understand the cleaning of the surface from dirt and grease. The threaded connection is recommended to be pre-treated with WD-40 or ordinary machine oil. It is also possible to alleviate the situation if several times to hit the debris with a hammer. Often the problem is solved by heating - a hairpin or a bolt, provided that it looks out of the hole, is heated with a soldering iron. Then it can be relatively easily removed.
How to unscrew a hairpin if it breaks above a thread
If in the process it was possible to break the thread even a little bit, that is, if the fastener began to turn out, you can try using pliers or pliers. A good and powerful adjustable spanner will also help in this difficult task . In the second embodiment, a hacksaw for metal or a grinder may be required. Sometimes a chisel is also suitable - the main thing is not to exert excessive efforts. How to unscrew a broken wheel stud in this way? Make a transverse hole for the screwdriver and unscrew the pin with this tool.
If the screwdriver did not help, then you can use the welding machine. This operation is easy enough. A bolt is prepared, the cap of which approximately corresponds to the diameter of the stud. Next, the bolt is welded to a fragment sticking out of the hole. Then with the help of a key and without unnecessary efforts they try to turn out the unfortunate hairpin. Experienced auto mechanics say that there are special adhesives with aggressive action that can be used as cold welding. But they are not always effective.
If the stud breaks below the surface or in the hole
In this situation, you will need a drill, a thin drill for it, as well as good skills in using the tool. Before you unscrew a broken pin from the engine block, you need to drill 2-3 or more thin holes in the body of the pin. Then these holes will have to connect into one single. A screwdriver is inserted here and they try to unscrew the fragments of the bolt.
Left-hand stud
The second method is more complicated. It is used when it is impossible to twist a broken hairpin in any of the available ways. In this case, the measures taken will be even more dramatic. This method will require an electric drill, tap and a lot of time. First, a hole is drilled in the hairpin - right in the center. Then, carefully cut the thread in the hole with a tap.
Note an important point: before unscrewing a broken pin from the head, make sure that the thread is “left”. When a new bolt is screwed into the just cut part, the thread of which is the same, then at the moment when it reaches the end, the broken stud will begin to turn out.
Drilling
And finally, the third and most radical way. It is used to remove broken bolts and studs from the hole. This is drilling. The method is very difficult. It is much more complicated than all of the above and is the most dangerous. There is a risk of damage to the threads in the bore of the engine block or cylinder head. The drill should be held firmly, since if it is a cylinder block, there is a serious risk of damage to an expensive part. The hairpin is often made of harder grades of steel, and the head is made of aluminum. The collector body is cast iron, so it is also softer than steel studs. The drill will definitely go from a hard stud to softer metal. Especially often this happens if the work is carried out in a limited space, and the drill is installed at a small angle. The principle of drilling is as follows: strictly in the center of the pin, you need to make a hole with a thin drill, having previously turned it, then set a thicker drill and repeat the whole procedure.
The main thing here is drilling strictly in the center. When there is practically nothing left of the hairpin body, the wall will become thin. It can be broken. It is necessary to break the remnants of the pin very carefully with a pre-sharpened wire or tweezers. It must be remembered that any actions are carried out as slowly and accurately as possible. If you act in a hurry, you will need to think not about how to unscrew the broken block pin, but also about how to restore the cylinder head itself. And this is a significant cost.
We use a conductor
The drilling operation of broken studs can be greatly simplified. This is true for those who often repair engines. The simplest conductor will help the master. Part dimensions are taken from real engines. On the conductor, and this is a metal plate, the same holes are drilled in the same places as on the head, as well as on the collector. Even in the conductor make holes for the bushings. They will keep the part from moving on the block.
Using such devices, it is possible to greatly facilitate the task and figure out how to unscrew a broken pin from the exhaust manifold by drilling, without damaging the collector itself.
Extractors
An extractor is a special device that allows you to remove the remnants of faulty fasteners or unscrew a broken hairpin. The device is very simple and at the same time brilliant. In order to remove a stuck or broken part, you need to hook it somehow, and then unscrew it. And all this is done very simply. It is required to drill a hole in the center of the pin, wedge some tool in it in the shape of a cone or cylinder, then use this tool to unscrew the bolt. This is the extractor. These devices greatly facilitate the solution of issues such as unscrewing a broken hairpin from the collector or from any other places.
There are several types of extractors:
- Wedge-shaped.
- Rod.
- Spiral.
- Screw.
Now these devices can be purchased in sets, but they are on sale and separately. Specialists recommend using these tools. They greatly facilitate the solution of difficult situations, such as broken bolts.
Steel selection for studs
Often auto mechanics themselves are engaged in the manufacture of studs. They recommend making these fasteners from such steel grades: 35, 40, 45, 50, 55, 60. If a new fastener is made of such metal, the result is a product with sufficient tensile strength.
If the studs will be purchased in stores, you should not choose the cheapest or those that you saw on the counter of the car shop. The most reliable products have a part number of 13517010. The penultimate figure indicates that this stud has sufficient tensile strength.
Before you screw the stud ...
In order not to think about how to unscrew the broken hairpin before starting work, it is recommended to lubricate the part with graphite, and preferably copper grease. Better to unscrew the element with the nut than to break it. Finally, the threads of the nut are also best treated with graphite grease. In the future, this will exclude breakage or kink of the part.