Transmission fluid leak

About an hour into our two and a half hour trip from Philadelphia to our cabin in the Poconos, the automatic transmission in our 2001 Ford Windstar skipped several times, and my son noticed a slight oily mist trailing us on the turnpike. The car still was driving OK, so we kept going. An hour later, we were going up a steep long hill and there was a noticeable lack of shifting by the transmission and a heavier plume out the back. We pulled over as soon as we could (at the top of the hill) and the back of the car was covered with an oily mist and liquid was dripping out the bottom. It was impossible to tell where it was coming from, as it seemed to be coming from everywhere. The oil level was fine and the coolant was good, so we let it cool a bit, then thought we would drive the 8 miles remaining while we figured out what to do. The car started fine, but would not go forward nor in reverse. We got towed the three miles to repair shop that was closing in three hours for the weekend and they said they would look it over in a little while and call us. They called right before closing and said they looked it over, and the transmission just overheated, so they drained it and refilled, and it seemed to hold, and we should be OK. I picked it up and drove for about 6 miles, and it didn’t slip, shifted well, and had power. In the 20 hours since their repair, there is no spotting on the ground under the car. I can’t imagine that there wasn’t a leak that had to be fixed (a seal, a hose?), and now I’m wondering if it is safe to drive the two and a half hours home tomorrow?

Is this possible that the transmission simply overheated and once refilled, it is all set to go? (But where did it leak from if it didn’t blow a seal.) We had never changed nor checked the fluid previously, though maybe our regular mechanic had checked it, but I doubt it… Maybe the fluid was low in this 10 year old car and that caused it to overheat? Eh?

It’s possible.
To determine a leak source, CLEAN all of the trans and engine area. Steam clean or spray on /hose off degreaser.
Then , as the leak begins anew, you’ll be able to see whence it originates.

Ken’s advice is good, but it does not go far enough, IMHO.
If I were the OP, I would be very concerned about WHY the transmission allegedly overheated.

The most likely cause has to do with the radiator, which also contains the cooler for the transmission.
In addition to looking further for leaks, I strongly suggest that the OP have the flow through his radiator evaluated, as it is entirely possible on an 11 year old vehicle to have a partially-clogged radiator–particularly if the coolant was not changed every 3 years or so.

The OP did not mention an overheating engine, but it would be a good idea to have the radiator’s electric cooling fan(s) checked as well.

I agree with Ken and VDC. The only thing I would add is that the trip home will be mostly downhill so you should have less problems with overheating. Make sure that you always properly check your transmission fluid level. An overfilled transmission will “spill it’s guts” so to speak because the transmission fluid will become foamy after it heats up. The only place it has to go is out which is usually at the top of the transmission through the vent tube.

Over filling was the first thing that occurred to me. Better to be a quart under than a quart over.

It may be a transmission seal that only blows fluid at highway speeds. Keep checking he fluid level to avoid major damage. I do not think your troubles are over, but vigilance can save you big bucks.

Yesterday was a very hot day. You were driving at high speeds. And you were in some pretty steep mountains. How loaded was the van? Were you towing anything? Did you have a roof top carrier on top? All factors that can challenge a cooling system.

I would like to find a reason for the overheating on this trip. What is the level of coolant in the radiator and overflow tank? Have you ever cleaned out the radiator? The radiator and AC condenser can get loaded up with dirt, bugs, and debris in a ten year old car and that restricts airflow and lowers cooling efficiency. If the cooling system was struggling perhaps the first area to show signs of stress was the transmission fluid.

The transmission fluid being so hot to vaporize and “vent” somewhere out of the system to the degree that it leaves a film on the rear of the car seems unusual. On the drive home, cut the speed down to about 60 to 65 mph and let the car lose some speed uphill and let it regain the speed on the downslope. In other words take it easy on the tranny until you regain some confidence that the problem is resolved.

I just wanted to thank everyone who took the time to offer advice on my transmission problem posted on July 7. Just to follow up: The local mechanic refilled the transmission fluid, adding 5 quarts, and it seemed to hold. We decided to drive home, taking the advice of riding as light as possible (2 bikes, 3 adults, a cooler of food, and some clothes) driving a steady 60-65mph with no AC. We stopped about halfway to cool off the car and to check the transmission fluid level, which was almost exactly mid-range. As we moved the car, I checked the ground, and there was a little spotting, but no puddles.

I suspect we had a very slow leak for a long time, and we ran the car up the big hills on a hot day, and the trans fluid just overheated and forced its way out somehow. We took it to our home mechanic, and he sees some evidence of a very slow leak at the passenger side axle seal. We’ll replace that, and hopefully, the problem will be solved.

Thanks for all your help. The postings gave us enough confidence to chance the drive home and the car made it easily!


Glad you made it, good luck and thanks for the postback :slight_smile: