My transmission fluid is leaking into my.

Thanks, I purchased a radiator today. Didn't know it was that expensive (lol) and got the coolant and transmission fluid.

Okay thanks, I had a mechanic to replace the radiator and all the other stuff too. Thanks so much. The truck rides good. Thanks so much

Since July of 2009, my SUV has been leaking transmission fluid from the vent hole while/after driving. I usually drive 40 to 74 miles each day, mountainous driving. It seems like the transmission needs to get hot before it leaks. It does not appear to leak once the transmission has cooled down completely nor does it leak while just sitting parked for several days at a time.

My local Ford garage finally localized the leak to the vent hole after initially thinking it was the transfer case gasket and transmission pan gasket leaking. They so far have been unable to determine why the fluid is coming from the vent hole since they have not yet opened up the transmission. They think that maybe the transmission fluid is possibly overheating and causing the fluid to expand to the point of leaking. They are currently attempting to connect some kind of gauge to the transmission to check pressures while/after driving but they are having difficulty getting the gauge connected due to the tight working space.

I am aware from your site that an internal leak could cause fluid to drain back into the transmission overnight, causing it to overfill and leak from the vent hole while parked overnight, however, my issue occurs while/right after after driving.

My transmission does slip a little every once in a while and sometimes will shudder a little after cresting the top of a hill when in overdrive. It also has occasional harsh engagement when in trying to put it in reverse. The garage has not seen any clutch material or metal chunks in the fluid the last few times they looked at it. Also, once after driving, the transmission would not go into any gear until it cooled down.

Could the solenoid pack cause all of these issues or could there be something more major at work? Could there still be some kind of internal leak that might cause these symptoms during driving as opposed to being parked overnight? Is a replacement transmission in my future?

I have been dealing with this for about five months and really need to get this resolved, hopefully before the snow flies. Thanks for your help!

Thanks for the reply. I had a transmission fluid flush done in February of 2009. Did not notice leak and slipping until late July. The garage assures me that, at the last fluid level check, the levels were where they should be.

Would the pressure tests they are going to do help to reveal restriction in the hoses or cooler? I'm not sure what is involved in checking the cooler and hoses for restrictions otherwise.

If the garage has not yet checked the cooler, hoses, and lines, I will make sure they do that next.

The reason I had the flush done is because my garage thought that whoever had the vehicle before me had another garage put the wrong type of fluid in the tranny. They recommended the flush to clear out the old fluid. To my knowledge, I think my vehicle takes Mercon V fluid which is what my garage says they put in.

Just prior to getting the flush done, the vehicle had been dropping out of gear and kicking back in harshly very regularly. After the flush, it stopped doing that and only recently started slipping a bit besides the leaking issue which started in July. My garage did use TransX right after the flush in February to help recondition the seals, etc.

They have added fluid over the last few months as needed due to the leaking and from when they replaced my transfer case gasket and tranny pan gasket but I have not had all of the fluid replaced again since the February flush.

Yes, my garage is a certified Ford dealer.

Service Manager at my dealership installed the gauge and drove the vehicle locally but could not reproduce the shuddering so far. He said the gauge showed nothing unusual. He said that he will try driving it along one of the more strenuous routes I normally take to try to get it to act up.

I asked if they had checked the cooler, hoses, and lines. He said that they hadn't yet. He stated that the gauge attached to my tranny will show temperatures. He said that if the gauge temperature doesn't show signs of overheating, he doesn't see a reason to check the cooler, etc.

Keep in mind that the Service Manager is currently not charging me labor on this continued investigation into my overheating/leaking issue since they previously misdiagnosed it back in August of 2009 by thinking it was the transfer case gasket and tranny pan gasket as the source of the leaks and charged me $700+ for those repairs. He is personally doing the current diagnosis, however, the process is slow since he's the Service Manager and can't work on my vehicle constantly. I'm trying to stay with my local dealer since I feel they need to make it right for not diagnosing it correctly the first time.

Service Manager called and said they drove it over the last few days with the gauge attached in one of the same strenuous areas I drive in. The temperature reading did not show anything out of the ordinary, nor were there any shift problems showing up.

Service Manager said that his recommendation is, if it were his vehicle, to just drive it as it is. He said that he would hate for us to have to put a bunch of money into the transmission if that wasn't really the problem. This is not a very reassuring recommendation.

It appears obvious that they have no idea what is causing the problems based on the tests they've done. The Service Manager gave no indication what should be next steps if we decided to keep pursuing a solution to the problems.

Not sure what to do now. There is obviously a problem and I fear one day this thing is going to let us sit before long.

Your thoughts?

I don't believe the Service Manager specifically checked for further leaking. He was mainly focusing on the gauge readings. He did not specifically say he checked again for leaking.

The last time it leaked for me (and would not go into gear until the tranny cooled down) was on November 7th which was the last time I drove it before taking it back to the dealer on November 9th. They have had it for 3 weeks now. The day I last drove it and had the "no gear" problem, it was a warmer day and all 4 family members were in the vehicle.

As long as the vehicle is driven consistently (several days or more in a row), it will leak. If it sits for while, short trips aren't enough to really make it noticeably leak until it is driven longer distances. The leak is slow enough that the dealer had trouble narrowing it down to the vent hole until they did the dye test recently.

I am supposed to get the Explorer back this Monday, November 30th. Seeing that nothing was done to correct the overflowing, occasional shuddering and occasional harsh engagement when putting it in reverse, I am pretty confident it will continue to do these things.

I will visually check the fins the next chance I get.

I just came across a Ford Technical Service Bulletin (00-23-10) that applies to my model and year.

https://www.2carpros.com/articles/mitchell1eautorepair-car-repair-manuals

It involves the cleaning, flushing, and backflushing of the tranny fluid cooling system and an in-line filter that needs changed when tranny overhauls/replacements are done. To my knowledge, I was told that my tranny had been taken out and either repaired or replaced sometime before I bought it used in February of '09. I have no idea if the cooling system was cleaned before I bought it or if the cooling system and in-line filter replacement was part of the transmission flush my dealer did in February.

This sounds like it has the potential to cause inefficient cooling. Is this something I should have my dealer look into?

The dealer didn't see any clogging of the fins on the cooler.

They did a flow test on the transmission yesterday. They said that they got about 1.5 quarts in a 25 second period coming out of the transmission and about 1 quart in 25 seconds coming out of the return line on the cooler that goes back to the tranny. The Service Manager said that the norm is to see about 2 quarts in 25 seconds when doing the flow test. He feels there is likely a restriction in the cooler but doesn't necessarily feel that doing a back flush will improve it much since they flushed it during the flow test and the rate didn't change. He is currently checking with some other folks on the Ford Hotline to see if the flow rate seems like the real source of my overheating issue.

Some possible options he is investigating (if the cooler really is the issue):

1. Replace the entire radiator (the tranny cooler is built inside the radiator on my Explorer, I'm told)

2. Add an new external cooler and bypass the old one.

3. Back flush the current cooler and install the filter kit (he's not too sure this will help much).

I'm hoping to hear more from the dealer tomorrow. What do you think of their findings?