How To Clean Shift Solenoid

How to clean the car solenoid valve

- Apr 23, 2019-

1. Before removing the valve body from the bottom of the gearbox, be careful when removing the flat wire of the external solenoid valve. Since the solenoid valve connector on the side of the flat wire is a plastic product, it is immersed in ATF oil for a long time, and it is very brittle at high temperature. Use a special tool made by yourself, completely insert it under the solenoid valve plug, and pull the plug and harness in this direction, properly place it. Well, take off the easy-to-drop parts, remember the original position, put the valve body into the kerosene for a long time, then take out the empty.
2. Place the valve body on a clean workbench, remove the connecting screw between the upper and lower valve body, hold the upper part of the valve body and the middle partition together and hold it together, and turn it over to make the middle partition upward. The unidirectional steel ball will not fall, and then pick up the partition for the next step. After removing the partition, before the plunger of the control valve body is disassembled, use the residual oil on the oil passage partition to copy the oil passage partition map with a slightly thick white cardboard, and insert the oil passage partition. All parts are marked one by one on the map for reference.
3. Put the valve body into clean kerosene and clean it with carburetor cleaning agent. Clean the oil deposited in the oil passage with a small brush. If necessary, wipe it with nylon cloth. Visually observe that there should be no cracks or deformation on the valve body. Each plunger should be operated flexibly with a small screwdriver. The surface of the piston should be free of cracks. Place the air-drying valve body on the table, inject a small amount of automatic transmission oil into each oil hole and oil passage, and take it from the partition. For each small part, take one piece of cleaning, dry it and put it into the valve body, and check that the parts should be intact.
4. Check if the plunger is stuck. In the control valve body, except for the manual control valve plunger, there is no limit device that can be taken out directly. The outer ends of all the plungers are limited. The limit device has a cylinder, a card and Three types of bayonet pins. The cylindrical limit device only needs to push the plunger inward, the limit pin can be detached, and the card or the split pin needs to be disassembled by tools. During the disassembly process, the finger or the screwdriver should be used to resist the plunger. At the moment the device is removed, the plunger pops up under the action of the inner spring.
If the plunger does not fall freely in the valve hole, you can use a wooden hammer or rubber hammer to gently tap the valve body to remove it. The stuck plunger can be ground with 1200# sandpaper and stained with ATF oil in the direction of the arc. Only the plunger can be polished. It can also be ground with toothpaste. The valve hole cannot be polished and polished to the standing valve body. The plunger can be slowly slid to the other side by its own weight under clean conditions. In the process of disassembling the plunger, it is best to repair the group, reassemble and then disassemble the other group to avoid misplacement between them.
Check the free length and diameter of the spring and check the free length and diameter of all springs in the valve body against the standard, referring to the information in the service manual. The new spring also needs to be checked in this respect. Leaking the one-way ball valve will cause serious shifting shock in the relevant gear position, and the wrong position of the throttle valve damping block will also cause the shifting impact to the middle position of the valve body. . Be sure to pay attention to the front, back, left, and right positions of all components. Any small mistakes will cause the valve body to not work properly.
5. Replace the sealing ring on the control valve body. Whether the working oil passage of the force applying device is sealed depends mainly on the following aspects: 1. The sealing ring on the working piston of the force applying device; 2. The piston sealing ring on the accumulator; The sealing ring on the control valve; 4. The sealing condition of the sealing ring on both sides of the clutch supporting inlet port.
During the overhaul, the seals of these four aspects must be completely replaced. Whether the accumulator piston has cracks or whether the piston ring is worn or not must be carefully checked. Otherwise, the automatic transmission is easy to burn the wiper after overhaul, usually driving about 3000km. Will re-ablation, and has a direct relationship with the above four aspects.
6. Wash and dry the partition, and check that the partition should not have large deformation. Carefully observe that each oil hole should be smooth and not leaking. See if there is any light leakage. Note that the old and new gaskets and baffles of the valve body must be in close contact with each other. Check that all the holes and oils on the paper pad are consistent with the valve body (this is important). At the same time, use ATF oil to soak the gasket to be installed for a few minutes, then press the step when disassembling, the valve body should be laid flat to push the components one by one, instead of erecting the valve body vertically. Then fasten the upper and lower valve body and the intermediate partition together and evenly tighten the connecting screws (note that the screws are long and short, do not install the wrong position). The tightening torque is generally between 5-10N roads. For example, the mass transit torque of the Volkswagen transmission control valve body is 5N m, which cannot be too large or too small, and the magnitude of the torque directly affects the oil pressure. At this point, the valve body is assembled. Under normal circumstances, it is necessary to replace the automatic transmission lubricating oil (ATF) every two years, and the automatic transmission needs to be cleaned and maintained every 40,000 kilometers.

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