What Causes Excessive Transmission Fluid Temperature?
3 Answers
Excessive transmission fluid temperature is caused by insufficient fluid volume. Excessive fluid temperature: Frequent operation or prolonged operation of the oil pump can lead to excessive fluid temperature, which in turn causes the fluid to thin and prevents the oil pressure from rising. External leakage in the hydraulic system: Address any oil leakage points, primarily on sealing surfaces. Examples include damaged oil pipe joint seals causing leakage, leakage at the sealing planes of components such as relief valves, solenoid directional valves, and hydraulic check valves integrated with the oil circuit, as well as external leakage at the piston rod of the oil cylinder. The diagnosis and handling of this fault are relatively straightforward and intuitive. Internal leakage in the oil cylinder: Internal leakage in the oil cylinder due to seal failure is not visible externally, making it more difficult and complex to determine whether the internal seals are worn or damaged. The diagnostic method involves first performing a clamping action with the oil cylinder until it stops advancing and the pressure no longer increases. Maintain the clamping action, then disconnect the return oil pipe from the oil cylinder joint. If hydraulic oil continuously flows out from the return oil pipe joint on the oil cylinder, and since the piston has stopped advancing, it can be concluded that the piston seal is damaged and needs replacement.
Excessive transmission fluid temperature is actually quite common. I've found it's often related to the cooling system, such as a clogged radiator or a non-functioning fan, which prevents the fluid from cooling down. It could also be due to insufficient fluid levels or degraded, aged fluid, leading to poor circulation by the oil pump. Additionally, driving conditions play a significant role—long-distance driving up steep slopes or towing heavy loads increases transmission stress, making fluid temperatures prone to spike. I must remind everyone to pay attention to the dashboard warning lights while driving. If you notice the temperature is too high, pull over immediately to check and avoid damaging internal components. For prevention, regular checks of transmission fluid and the radiator are key. It's best to change the fluid approximately every six months to keep the system unobstructed. You can simply check the dipstick to confirm fluid levels, but for complex issues, it's safer to visit a professional repair shop—safety first.
Having driven many cars, high transmission fluid temperature is usually caused by excessive load, such as frequent hard acceleration, overloading cargo, or prolonged stop-and-go traffic. Additionally, dirty fluid or leaks in the radiator lines can also lead to this issue. It's recommended to maintain a steady speed while driving, avoid carrying heavy loads uphill, and prevent prolonged low-speed driving. If the fluid temperature gets too high, don't push it—turn on the hazard lights, pull over, and let it cool down. For maintenance, remember to change the fluid and clean the filter regularly, and repair the cooling fan immediately if it fails. Don't underestimate this issue, as it could lead to a complete transmission failure and costly repairs.
