Transmission fluid leaking less than 24 hrs after a flushj

Took my 2003 Trailblazer to local Monroe yesterday @ 3:30pm to have a transmission flush. After about 1 1/2 hours, it was finished. I went home-- car drove fine. Parked in garage and about an hr later, took my son to his band concert. When we got 5 miles up the road to his school, we smelled a slight hot burning smell-- like oil spilled on an engine, sort of. Thought perhaps they might have spilled a little bit of fluid on the engine or something. Made mental note to call them in the morning to ask about it. When I backed out of garage this morning, I saw red drips in the snow. I pulled out in the road, called to tell them the problem, told them I needed an appt right after work to fix problem. About 5 miles up our road, I realized I didn’t have the amount of acceleration power I was supposed to have-- turned around and went home. Could not get fully up the driveway. Called Monroe and told them the problem and that my husband would be having the car towed to them today. I checked the fluid in the transmission and it was almost BONE DRY. !!! I want to make sure I sound knowledgeable when I speak to them next on the phone today. Other than someone who did not fasten everything correctly after the flush was performed, what else could have been done incorrectly to have caused this? Obviously, I am going to insist that they fix this leaking problem at their cost, but am I also looking at the possibility of any permanent damage to my transmission-- and if so, how would I know? If there is permanent damage done, what is my recourse with this Monroe garage and what is the best way to handle it?

In order to do a transmission fluid exchange one of the transmission cooling lines had to removed from the radiator to connect the fluid exchange machine. If the fitting for this line wasn’t tightened or was damaged when the line was reconnected to the radiator, transmission fluid will be pumped out of the transmission very quickly.


Tester is correct, as usual.
Please take this experience as evidence of what we always recommend in this forum, namely–DO NOT take your vehicle to Midas, Meineke, Monro, Sears, Pep Boys, AAMCO, or any other chain operation if you want good workmanship and fair prices. You would be far better-off if you utilized an independent shop for maintenance and repair.

Good luck with your Trailblazer!

I concur with the previous posts. Take this experience as a lesson learned.

Well, I certainly never will again-- that is for SURE! I used to go to a locally owned oil change place for my oil changes and transmission flushes (unaffiliated with any major chain) but they went out of business. So, I’ve been going to this Monroe for the last year or so, with no problems so far with the oil changes. But, I certainly won’t be using them (or any other chain similar to this) EVER AGAIN.

Thank you so much for the words of wisdom, and the good luck well-wishes!

So the likely cause has been noted.

The damage? Well, that’s where things get difficult. By the sounds of it you did drive around with your transmission slipping - something on the order of more than 5 miles. Then there’s the amount of slipping you let it do trying to get up the driveway. This is bad - the slipping overheats everything and cooks the clutches.

Its quite possible that you can have the leak fixed, transmission refilled, and everything with be good to go. Its possible that some miles have come off the transmission but not possible to say how many. It also is possible that you completely cooked it.

So the problem you’re going to face is that it is much more than likely that the leak is their fault. But no one at the shop was involved in driving it while it was slipping. They certainly owe you a tow, leak repair, fluid service etc. But they are more than likely to deny responsibility for any actual damage done.

Well, that’s not exactly true. The mechanic DID drive my car after he performed my flush! I’m assuming like around the block or so in the maze of parking lots that surround this Monroe. I’m assuming he drove it probably for 3-4 minutes. I went up to the desk, paid, asked a few questions, and went outside. I waited outside for about 30-45 seconds before he drove into the parking lot and up to the door, leaving the Trailblazer running for me. So, since the mechanic drove it after the flush, does this leave the dealership holding more of the bag of responsibility then? (I certainly don’t wish to sue anyone. I have never taken anyone to court. But, I want to make sure I have my ducks in a row to try to make them fix anything that may have been done wrong.)

Thanks for all the great advice, and, in advance for any future posts. :slight_smile:

First, keep in mind that no one is yet actually certain about what happened.

But lets just go on the assumption that Tester is right (b/c it is the most plausible thing).

When the vehicle was taken for a test drive after the service it was still full of transmission fluid. It probably drove normally and there was no reason to suspect a problem. It was over the course of driving it that the fluid was lost. It was then the lost fluid that led to the slipping. I hate to say it, but at the first sign of something odd you should have stopped driving and checked the fluid.

So no. If the scenario that’s been assumed here is correct, no one at the Munro shop drove it with the transmission slipping.

True. Point taken. Just wanted to make sure. One last question-- was the smell that I smelled last night the beginning indication that transmission was slipping? (It was driving fine last night when we went to the concert) or was the acceleration trouble this morning when it was slipping? Just trying to figure out how much damage may have possibly been done. Sigh. :slight_smile:

If the line was leaking, transmission fluid can spray out and come in contact with hot engine components causing the smell. The slipping occured this morning.


The smell was likely leaking fluid hitting something hot like the exhaust manifold.

The slipping is indicated by you saying that you didn’t have the acceleration/power that you normally do and the truck not making it up the driveway. Presumably the engine would rev up but the power of the revving engine wasn’t making it to the wheels. That is the slipping.

So here are two things to take away. The first is to avoid the chains. But the second is to always be in touch with weird changes in what your vehicle does - but especially right after it has been serviced. People do make mistakes, no matter what their job is or what kind of place they work in.

Keep your fingers crossed. You may just be able to have the leak fixed and drive on.

In fact, if it hasn’t been towed yet you should be able to just fill it up and drive it back to the shop. I wouldn’t do that b/c I’d want the shop to get it in exactly the condition it is in.

When the shop does get their hands on it, if they identify it as some other kind of leak issue that is unrelated to their work (a possibility) ask them to show you. Configurations vary and I don’t know the specific set up on a trailblazer. But in general, there are tubes that run from the transmission through something that will cool the fluid - often the lines run right to the radiator. Sometimes there is an additional or alternative auxiliary cooler that looks like a little radiator. What Tester is referring to is the point where those lines screw into the radiator/cooler. But there are other things that can happen. So if they want to say it is something else, make them show you.

Okay. :slight_smile: Well, that makes me feel a bit better. I didn’t push down on the gas very much when on the road. Just as much as I had to in order to keep the car at 25-30 mph, and I only accelerated maybe 4 times, just slightly, in order to get it started when I was turning around. I didn’t accelerate at all trying to get up the driveway-- I just pulled in and let it coast up as far as it would go. So, I didn’t do as much damage as I would have, if the slipping had started last night. Thanks for the great advice! :slight_smile:

ANY amount of slipping is never good. Those clutch plates which were slipping are only THOUSANDTHS of an inch thick. Pressing down down on the accelerator just eats them up faster. The transmission IS damaged from this. How long it will last is anyones guess. If the leak is coming from one of the cooler lines, they are responsible.

Just out of curiosity, did they drop the pan and change the transmission filter prior to “Flushing” your transmission??


The transmission has permanent damage. It may even appear to work acceptably well when they give it back to you with the announcement that everything is fine now but do not be fooled by this.

No power, won’t pull itself up the drive, almost bone dry - it’s toast.

Interesting that you should ask that. My husband texted me in the middle of the flush and asked me if they were also changing the filter. I inquired at the desk and they told me, “no. It’s not recommended that you change the filter at the same time that you’re doing a flush.” Then they said something about putting in a new filter would just catch all the gunk from the flush and it would be better to change the filter at another time. They said they could change the filter if I wanted them to, but that would be an additional charge. Well, naively, I said, “well, if you don’t recommend changing the filter at the same time as the flush, when should I come back and get it done?” They said the filter was not necessary to be changed very often, so not something that I really needed to worry about.

Did I make a mistake there also? Should they have also changed the filter?

I want to first-- thank everyone for their help! THANK YOU! and second-- let you know the outcome of the trailblazer problem. I called the Monroe shop in question, and the owner was VERY apologetic on the phone, and assured me that they would correct any problem that may have been caused by this (I’m assuming bc he thought it was the shop’s fault due to not tightening everything correctly, etc.). He let me know that my transmission was fully covered if there was any permanent damage, now or in the future, for this lack of fluid problem if it was due to their fault. But, in order to cover this damage, I needed to bring it to them so they could see first-hand what the trouble was. We had it towed on the afternoon of the 23rd-- and both the owner and a mechanic went under the car and inspected everything step-by-step, allowing me to be in there with them the whole time, and explaining everything to me (what they were looking for, what they found, etc.). Turns out, there was a little bit of fluid in there (so it wasn’t bone-dry), everything was tightened correctly, and the leak wasn’t their fault after all. When they put new fluid in the transmission, it started to leak profusely from under the engine cover between the wheels! Not even close to the radiator! So, they took off the engine cover and transmission fluid was streaming out of one of the transmission lines/metal tubes that run from the radiator to the transmission. It looked like a tiny constant pouring thread of oil-- coming out from a pinhole in the tube. The tube was rusted/corroded in one area of the tube, where a clamp holds it to the undercarriage of the car. Apparently, when the old fluid was flushed out and the new fluid put in, either the pressure of the new fluid or the “anti-corrosion” agents in the fluid loosened a bit of that rust that was inside the tube (at some point on my 15-20 minute ride home) and a pinhole leak emerged. By the time I got home, my husband smelled that smell, so we know it was leaking by then, but the mechanics say there was no leak evident after the flush before they put the car down, and they don’t put the car back up after the testdrive. So, there’s no way of knowing whether it started leaking immediately when it was driven, or at some point on the way home. Regardless, when the owner asked me more about how the car was accelerating that small amount of time before I took it back home that initial morning, he told me that it sounded like the car went into “limp mode” or safe mode, not allowing me out of first-gear. He said this might mean that the computer kept me from doing alot (or any) transmission damage to my car. I hope he’s right.

End of the story-- they worked on my car Christmas Eve, even paying 2 of their guys 3 hours of overtime to get both metal tubes replaced (the other one was also starting to corrode in the same spot) and only charged us $84 for parts and labor. We drove it around town all last week with no evident problems and had to drive it 6 hours yesterday to take my older son back to school. No problems yet. My father says this is a reminder to me that I should never have a flush done, but a drip fluid change instead from now on. :slight_smile: Hopefully the mechanic was correct, and there was no damage done. Either way, we are thankful for God’s help and all your great expert advice! THANK YOU AGAIN!

Thank you very much for the followup report. It happens rarely.

I’d have to say that the Monroe location you went to sounds like a good place (many chain locations are not). I say that partly b/c they were happy to how you exactly what was going on and then to fix it for you cheaply. As you tell the story, it actually wasn’t their fault so it was mighty nice of them to get you going so quickly at such a reasonable repair price.

Normally people are warned away from chain repair locations but it does sound like this one might be ok to use.

The limp mode story is plausible, by the way.

My feeling is that the transmission was low enough on fluid that some damage was caused. How much is the great unknown here.

The story you were given is plausible but it’s also possible that if someone were a bit heavy handed disconnecting the cooler lines at the radiator they could have stressed those lines back near the transmission and created this leak.

I would think that if the condition of the lines are that bad they would have noted this and warned you of it. If I were rotating tires and saw steel popping out of a tire, changing engine oil and saw a damaged oil pan, etc. I’d tell the customer about it.
Just food for thought anyway.

The shops staff rose to the occasion and I am proud for you that they did. There actions speak highly of them. It’s a shame that such professionalism is the exception and not the rule. Hopefully there is no internal damage to your transmission. And thank you for posting the good news here. I am one of the worst to shake my finger at shops that lie and deny away their possible guilt due to inept service.

Never, EVER flush a transmission without first dropping the pan and changing the filter. They told you that it is not recommended that you change the filter when doing a flush. Ask him what happens to all the trash on the bottom of the pan. Ask him about the trash in the filter. They did not do a satisfactory service to your transmission. People out there say just dropping the pan, changing the filter and refilling is doing half job. Well flushing or exchanging the fluid without dropping the pan, cleaning it out and changing the filter is doing half job. Yes, you did change 98% of the fluid but all that trash in the pan which didnt get cleaned out is now mixed in with the new fluid. I have 27 years rebuilding automatic transmissions and can tell you with all certainty that they did not properly service your transmission. Do yourself a favor and dont ever let these clowns touch your transmission again. Take it to a real transmission shop for service.