What Causes a Transmission Fluid Leak in a Dodge Caravan?by Tony Oldhand
When new, a Dodge Caravan transmission should not leak. However, all mechanical parts eventually wear out, and the transmission in a Doge Caravan is no different. Coolant-line fittings may come loose, or transmission seals may go bad, and start to leak. Seals are readily available at any auto parts store and are relatively inexpensive, but replacing seals or gaskets can be labor intensive and expensive, depending on the location of the leaky seal (the engine may have to be pulled to get at it). Even so, finding and fixing a problem early is the key to preventing a small problem from becoming a large one, like a burned out transmission.
Bad Front Main Seal
This is the seal on the transmission main shaft, behind the torque converter. This seal is not easy to replace--it usually involves separating the engine from the transmission, or even removing the engine or transmission completely. This is not a job for the home do-it-yourselfer, but is best performed by a qualified auto repair technician.
Bad Axle Shaft Seals
These are the side seals, where the axle shafts insert into the transmission. While difficult to replace, the home do-it-yourselfer can do this with a little patience. It is recommended that one side be done at a time, since the Caravan will have to be jacked up, and the front steering spindle loosened to pull the axle shafts out.
Bad Transmission Pan Gasket
There is a pan on the underside of the transmission which is removable to change the transmission filter. The pan gasket may be bad, resulting in a leak. This is the easiest of all the gaskets to replace. Since it is under the transmission it is relatively accessible, and only requires the removal of bolts, and then the pan, to replace.
Loose or Worn Transmission Line Fittings
The Dodge Caravan, like most vehicles, has a transmission cooling radiator, with lines that run from the transmission to the radiator and back. They attach by threaded fittings, and over time, due to heating, cooling and vibration, these fittings may become loose or worn. When they become loose, they allow transmission fluid to leak. The way to fix this is by tightening all loose fittings snugly (but not overly tight, otherwise the brass threads will strip). If worn, the line should be replaced, since the fittings are usually flared and are not removable from the line.
Broken Transmission Lines
The transmission cooling lines themselves may develop leaks. When the metal lines rub against metal parts, they will chafe until there is a hole. These holes then leak fluid. The cure for this is to replace the leaking transmission line with a new one, making sure the new line does not rub against parts that may chafe it.
Hole in Transmission Radiator
The transmission radiator may develop a hole, due to corrosion or from a kicked-up object from the road (such as a rock). The way to determine this is to closely inspect the radiator for leaking transmission fluid. If this is the problem, the cooling radiator must be re-cored or replaced.
Tony Oldhand has been technical writing since 1995. He has worked in the skilled trades and diversified into Human Services in 1998, working with the developmentally disabled. He is also heavily involved in auto restoration and in the do-it-yourself sector of craftsman trades. Oldhand has an associate degree in electronics and has studied management at the State University of New York.