Four Common Causes of Transmission Leaks

A transmission leak spells serious trouble for your car, truck, or SUV. Transmission fluid is also called transmission oil because it lubricates and protects transmissions parts just like motor oil lubricates and protects other engine parts. If you have a leak, low fluid levels can affect the transmission’s performance and damage crucial parts. Transmission fluid is usually red to dark red; it’s pink if there’s a real problem. Accurate Auto lists four causes of transmission leaks below.


Your vehicle’s transmission has a series of seals that are made from either rubber or metal. With an average temperature of 195 degrees Fahrenheit to 220 degrees Fahrenheit, things get pretty hot underneath your automobile’s hood and the seals are affected by this heat. The wear and tear can eventually crack the seals, especially the pan gasket, and transmission fluid will leak through them.


Much like your brake or coolant lines, transmission fluid travels through transmission lines to various areas in your transmission. These lines are made from aluminum or steel. These lines are extremely durable and built to last, but heat and age can cause them to crack. Once they do, well, you guessed it. Transmission fluid will leak out of them rather than circulate through the transmission.


Transmission fluid is pushed through the lines by the transmission pump. Because the pump is a workhorse it can be a common source of transmission fluid leaks. Usually, the body of the pump cracks somewhere and fluid leaks out of it or is pushed out when the pump propels the transmission fluid throughout the system. In this case, a new pump is generally in order.


Finally, installing a transmission is serious business and if it isn’t done properly, fluid will leak out of it. The most common source of a transmission leak due to faulty installation is from the transmission pan. The pan is not mounted correctly or incorrect bolts are used to secure it. Something as simple as these bolts will make transmission fluid leak from the pan. Hopefully, the bolts just need to be tightened.

Accurate Auto works with vehicle transmissions, including maintaining and repairing them. Bring your vehicle into our shop if you have a transmission fluid leak. We have three shops in the beautiful state of Oregon from which to choose. We’d be happy to find the source of your vehicle’s transmission leak and fix it.

Photo by Kossvideo from Getty Images / Canva Pro

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