How did water get into your transmission? Finding the answer can be tough. There are several possibilities and pinpointing the exact source can be a challenge.
Every transmission has a line or hose that connects it to the radiator for cooling. Transmission fluid circulates through a sealed line inside the radiator for cooling and then goes back to the transmission. If there's a leak in the line inside the radiator, water/coolant can mix with the transmission fluid and flow back into the unit.
Another possible point of entry is the pressure-vent in the transmission body. All transmissions have a vent to balance barometric pressure inside the unit with the air outside. If the vehicle goes through a deep puddle or stream, water can reach the vent and be sucked inside.
It's common for cars to have a dipstick for checking the level and condition of the transmission fluid. Sometimes, during efforts to spray-clean the vehicle's engine or while going through a carwash, water can make its way down through the dipstick tube into the transmission. For this reason, there have been recalls of vehicles to correct problems caused by poorly positioned dipsticks.
Regardless of how the water gets in, it can do a lot of damage!
Why is it so bad? After all it's just water. When water gets inside the transmissioin it can soak the friction linings of the clutches. Once the clutches absorb enough water, the adhesive glue that holds the friction material on the clutch plates can dissolve. Besides that, the water will create rust on ferrous metal parts. Worst of all, fragments of friction lining can break loose, circulate within the transmission and destroy the pump.
One solution that many do-it-yourselfers try is to flush the transmission by adding new transmission fluid and draining the old fluid repeatedly. This is not a good idea. It will take gallons of expensive fluid to try this approach and in the end it won't get all the water out and there will still be tiny bits of friction material circulating.
The extent of the damage will depend on how much water enters the transmission. It doesn't take a lot (a quarter of a cup will ruin the unit) and the damage can be exacerbated the longer the water stays in the unit. The best solution is to take action as soon as you know the fluid has been contaminated. Turn off the engine. Call a reputable transmission repair shop and have your vehicle towed there (don't drive it to the shop). The right way to solve this problem is to do an overhaul on the transmission which will get rid of all the water and pieces of debris. If your radiator fails or you see that your transmission fluid has a frothy "milkshake-like" appearance, call us right away and we'll take care of it.
Waves offers a vast set of services and solutions that help you achieve the desired result.