i have a 1994 volkswagen jetta 3 GL an im tryin to locate the transmission vaccum hoses becuse my transmission isnt changein gears an we think it might be a vaccum hose but it shift like if us manualy shift it like going through the low range gears
They used to use a vacuum hose to a round diaphram modulator near the bottom of the transmission, just above the oilpan. I thought they had changed, first to a bowden cable, then to electronics. So I doubt they use a vacuum modulator any more. When they did, it was checked by removing the hose to see if there was any ATF in it. If there was, then it had to have a cracked diaphram. First start by checking the fluid level. If the transmission fluid level is low be sure to check your transmission for a transmission fluid leak. A leaking transmission is usually caused by a bad seal, gasket, o ring or transmission cooler line. If the fluid is dark or smells burned, it is time for a rebuild. But if low, then that may be all it requires. Make sure you check with engine running. Second have your vehicle scanned for computer diagnostic trouble codes. These codes help determine what component or circuits are failing. Now a transmission with a shift control problem can be due to an electronic computer control component or part. Computer control problems are usually due to a bad sensor, circuit wiring or computer itself. Some transmission problems can be caused by a bad transmission temperature or speed sensor. Transmission shift control problems can also be caused by a bad engine load sensor such as bad throttle position sensor. A slipping transmission can be due to the transmission losing internal oil pressure. Oil pressure is lost when internal sealing rings or seals fail to seal the clutch drum piston circuits. Although some manufacturers specify that their transmission fluids are for a lifetime, you should consider changing it out every 50k miles. So be sure to service your transmission to help prolong the life of your transmission.
