Caution: If the process plug is completely recessed into the cooling jacket channel, it will be extremely difficult or impossible to remove it from there.
1. There are technological holes in the cylinder block. They are needed to install rods that form cavities inside the block when casting it. After casting and disassembling the casting molds, these holes are closed with plugs. The plugs, in addition to their technological purpose, also have a functional purpose, preventing the block from rupturing when the coolant freezes in it.
2. The plugs can be pressed or screwed into the block on the thread. Threaded plugs can be unscrewed using a suitable key (they usually have either a hexagonal protrusion or a socket for an Allen key).
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Press-fit plugs are typically round sheets of sheet metal. To remove such a plug, hit the edge of the plug with a hammer through a punch with a blunt end, turn it in the hole and pull it out with pliers (figure 15.2, a, b).
3. Use a scraper to remove any remaining gaskets from all surfaces of the block. During this operation, be careful not to damage the treated surfaces.
4. Remove the main bearing caps or crankcase (on a V-engine) and remove the main bearing shells. Label each insert with the pore number and whether it is in the block or in the cap, then set them aside.
5. Unscrew all the threaded plugs of the oil channels from the block. Usually the plugs are screwed in very tightly and it is impossible to unscrew them - in this case, they need to be drilled out, and the threads restored with a tap. When assembling the engine, screw in new plugs.
6. If the unit is significantly dirty, take it to a service station for steam treatment.
7. After returning the unit from steam cleaning, clean all openings and channels of the lubrication system again. There are various special brushes available for this purpose. Flush all channels with hot water until the water running out is clear. Dry the block thoroughly and lubricate all treated surfaces with light liquid oil to protect against corrosion. If you have compressed air available, use it to dry and blow out the ducts.
Caution! Protect your eyes when working with compressed air.
8. If the block is not too dirty, it can be washed in a warm soapy solution with a stiff brush. Take your time to do this work and do it as thoroughly as possible. Regardless of the cleaning method, thoroughly clean all oil holes and channels, dry the block and lubricate all treated surfaces with light liquid oil.
9. To ensure proper tightening of connections during assembly, all threaded holes must be clean. To remove corrosion, thread sealant residue and dirt from the holes, and to restore damaged threads, run a tap of the required size through the holes (figure 15.9). If possible, blow out the holes with compressed air after this operation. Also use a die to run through the threads of the cylinder head mounting bolts and main bearing caps.
10. Reinstall the main bearing caps and tighten them with bolts by hand.
11. Coat the seating surfaces of the new process plugs with a suitable non-hardening sealant and install them into the block holes (figure 15.11). Make sure the plugs are tightly seated and not crooked, otherwise coolant may leak. There are special mandrels for pressing in plugs, but you can do without them. by selecting a suitable socket head or a piece of pipe with treated thorium.
12. Apply non-hardening sealant to the threads of the new oil passage plugs and the block threaded service plugs, screw them into place and tighten them securely.
13. If you do not intend to begin assembling the engine immediately, cover the block with a large plastic bag to protect it from dirt.