What Happens When Coolant or Water Enters Your Transmission
At Gold Coast Transmissions, one of the most common—and serious—issues we encounter is transmission failure caused by coolant or water contamination. If your fluid looks like a strawberry milkshake, it’s not a coincidence. That mixture of coolant and ATF is a sign that your transmission’s hydraulic system has been compromised. Here’s what causes it and how it damages your transmission.
How Does It Happen?
Radiator Failure
Many automatic vehicles rely on radiators with built-in transmission coolers. When those internal walls crack or corrode, engine coolant leaks into the transmission fluid, blending into a foamy pink mess that can no longer protect your transmission.
Water Intrusion
If your vehicle is driven through deep water or flood conditions, water can enter through the transmission vent or exposed seals. Once inside, the damage begins quickly—especially in South Florida’s humid climate.
What Coolant or Water Does to a Transmission
Once foreign fluid gets into the system, it starts breaking things down from the inside:
- Lip Seals Swell
Water and coolant make rubber seals expand unevenly, which causes hydraulic leaks and pressure loss. - Clutch Material Breaks Down
Contaminated fluid causes friction material to flake off the clutches, leading to slippage, RPM flares, and inconsistent shifting. - Electronics Short Out
Moisture can damage solenoids, sensors, and valve body circuits, leading to unpredictable performance or total failure. - Internal Corrosion Begins
Metal components inside the transmission begin to rust, affecting long-term reliability and response.
What We Do About It
At this stage, the transmission isn’t just struggling—it’s compromised. And no amount of fluid replacement or stopgap repairs will reverse the damage.
At Gold Coast Transmissions, we don’t patch things up—we rebuild. If your transmission has been contaminated by water or coolant, we’ll:
- Tear down the entire unit and inspect for internal damage
- Replace clutch packs, seals, bearings, and electronics as needed
- Flush or replace the radiator or cooler if it’s the source of the contamination
- Test and reseal the system to restore factory-grade hydraulic function
This is a serious job, and we treat it with the care it deserves—because your transmission isn’t something you can afford to gamble with.
Get Your Transmission Back in Working Order
If your vehicle has driven through water, is showing signs of overheating, or your fluid looks cloudy, it’s time to take action. Whether the damage came from a failed radiator or a flood zone, our job is to get your transmission working again—reliably and professionally.
To learn more about water intrusion and flooding from storms affecting your transmission: Click Here.
Further questions about your transmission? Give us a call at either shop:
Fort Lauderdale: (954) 983-3005
Davie: (954) 472-2662