How to troubleshoot some faults in the automatic transmission hydraulic control valve body

Automatic transmission electronic control system, hydraulic system, mechanical force devices are closely linked to each other. The hydraulic system, especially the oil control valve body is very sophisticated, like a maze like a printed circuit board oil channel, the size of the plunger, the length of the different thickness of the spring, ball, plastic ball, filter seat, limit Bit-slice, accumulator and other titles can be said that a variety of parts orientation, location, size can be described as dazzling. To repair the valve body must have detailed information, fully understand and look after the hands. For the AT gearbox, only when the friction plate is severely burned, the planetary gear wear, the vehicle mileage of partial 1/4, ATF oil serious dirt will consider the body to disintegrate cleaning and overhaul. Electrically controlled hydraulic automatic transmission, oil control valve body failure mostly due to internal dirty, clogging the oil caused. Disintegration of the body is overhauled repair an essential part of automatic transmission. 1, the valve body removed from the bottom of the gearbox, you should first remove the external solenoid valve flat wire, be extra careful. Since the solenoid valve on the side of the flat wire is plastic, it is submerged in ATF oil for a long time. It is very brittle under high temperature. Use self-made special tools to fully insert the lower side of the solenoid valve plug and unplug the plug and wire harness in this direction. Good, remove the appearance of easy to fall pieces, remember the original location, the body into the kerosene soak for a long time, and then remove the empty net. 2, the valve body placed on a clean workbench, remove the upper and lower body screw connection, the upper part of the valve body and the middle of the partition together with a firm hold, at the same time turn over the middle partition upward (the move Can make one-way ball will not fall), and then pick up the separator for the next homework. After removing the bulkhead, before removing the plunger of the control valve body, use the residual oil on the bulkhead of the oil path, make a copy of the hydraulic bulkhead figure with a piece of slightly thick white cardboard, All the parts are marked on the map one by one so as to be ready for reference after loading. 3, the body into a clean kerosene, carburetor cleaning agent can be used to clean up the small brush deposited in the oil in the oil, if necessary, with a nylon cloth wipe the visual inspection of the valve body should not have cracks and deformation, Pull each plunger with a small screwdriver should be flexible operation, the piston surface should be free of cracks, the dry valve body flat on the table, to the oil hole and the oil channel into a little automatic transmission oil, while taking from the partition Under the small parts, take a piece of cleaning, dry into the valve body, at the same time check the various components should be complete and good. 4, check the plunger is stuck, in the control valve body in addition to hand-controlled valve plunger no limit can be directly out of the device, the rest of all the plunger has a limit device on the outer end, the limit device cylindrical, card and Three kinds of bayonet pins. Cylindrical stopper simply push the plunger inward, the stopper pin can fall off, the card or cotter pin is required to be demolished, during the demolition process with finger or screw to resist the plunger, in order to prevent Bit device disassembled the moment, the plunger spring inside the pop-up. If the plunger in the valve hole with a jam can not fall freely, can be taken with a wooden hammer or rubber hammer gently tap the body to remove it. Jammed plunger available 1200 # sandpaper stained with ATF oil along the arc direction grinding, only polished plunger, can also be used toothpaste grinding, can not polish the valve hole, polished to stand on the valve body. Plunger on a clean premise, only rely on their own weight can be slowly slipped to the other side of the position. Disassembly process of the plunger, it is best to overhaul a group, reassembled and then split another group, so as not to install the wrong position between each other. Check the spring free length and diameter, one by one contrast to the data on the maintenance manual to check whether the free length and diameter of all the springs in the valve body meet the standards. New for the spring also need to do this check, missing one-way ball valve will result in a serious gear shift shocks, while the throttle valve damping block installed in the wrong position will cause shift shock <central body position, look like Card>. Be sure to pay attention to all parts of the front, rear, left and right adjacent position, any little mistake will lead to the valve body does not work. 5, replace the control valve body sealing ring, the force of the working device is sealed mainly depends on the following aspects: 1. The force acting on the piston seal; 2. The piston seal on the accumulator; 3 The sealing ring on the control valve; The sealing condition that the clutch supports the sealing ring on both sides of the oil inlet. When the overhaul of these four aspects of the seal must be completely replaced, whether there is a crack in the piston of the accumulator, the piston ring is worn must be carefully checked, or overhauled automatic transmission can easily burn the friction film, usually driving 3000km force device Will be ablated, with the above four aspects are directly related. 6, the separator washed and dried, while checking the separator should not have a larger deformation, carefully observe the oil hole should be smooth and light leakage? Note that the old and new body gasket and the diaphragm must be close together, check the paper pad on all the holes and the oil flow is consistent with the body (this is very important). At the same time with ATF oil soak the seal to be installed a few minutes, then press the step of disassembly, the valve should be placed flat parts one by one, rather than the vertical erection of the valve body. Then the upper and lower body, the middle partition together, cross evenly tighten the connecting screws (note the length of the screw, do not install the wrong position). Tightening torque is generally between 5-10N m. For example, Volkswagen transmission control valve body bolt tightening torque of 5N m can not be too large or too small, the size of the torque directly affects the hydraulic pressure. At this point the valve body is assembled.