Transmission Line Leak?

Hack12

Hack12

New member
For starters, I have a 2008 JKU Sahara with 61,000 miles and an automatic transmission.

While changing my transfer case and differential fluids today, the technician at Valvoline noticed transmission fluid leaking out of a line under the engine.

I have an appointment with my dealership tomorrow morning to fix my gas regurgitation issue and change my transmission fluid. I chose not to have my transmission fluid changed at Valvoline because they only offer a flush and I wasn't sure whether I should do that or drop the pan and change the filter.

My questions are:

1- Does this look like a leak and, if so, will it be expensive to have it fixed while my Jeep is at the dealership tomorrow?

2- Should I have the dealership flush my transmission fluid or drop the pan and change the filter?

3- Though Valvoline had the ATF+4 properly recommended for transfer case fluid, they recommended 75w140 for the differentials. Following the Project JK write-up, I told them to use 75w90 synthetic in both the front and rear differentials. Did I do the right thing by choosing to use the 7w90 synthetic gear oil?

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Well, that does look like ATF and it isn't uncommon for leaks to occur at the quick connectors. Although, it's more common to have something like a steering gear leak that dribbles onto other lines. I would do a thorough check of things before coming to any definite conclusions.
 
Is the 75w90 synthetic the right fluid to use on my differentials? I went by your write-up on Project-JK because I trust it more than the tech at Valvoline. Lol
 
Hack12 said:
Is the 75w90 synthetic the right fluid to use on my differentials? I went by your write-up on Project-JK because I trust it more than the tech at Valvoline. Lol
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Yes, that's what you want to use but really, there's no harm in running a heavier fluid. If you're do any towing, you'll want to run 140 in the rear. If you run a higher gear ratio like a 5.13 or higher, you might want to consider 140 as well as your diff will run hot.
 
Hydraulic lines (they carry pressurized fluid) such as these are inherently flawed due to their cheap construction. The swage or crimp, where the rubber line is connected to the metal tubing is low grade aluminum. Over time and repeated heat/pressure cycles, the aluminum loses it integrity and ability to seal the rubber to the metal tubing, thus causing small leaks like this to appear. In my opinion, you can either live with it (cleaning it up and servicing transmission as required) or change the lines and possibly relive the same problem 80-100k miles from now.
Ask any ZR1 S10 owner about these types of lines.

The best way to determine whether they are truly leaking or not, is to wipe them down and see if the fluid reappears after a few days. No need to drop the pan unless filter is due for replacement.

BTW, never flush your transmission!
 
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Markymark420 said:
Hydraulic lines (they carry pressurized fluid) such as these are inherently flawed due to their cheap construction. The swage or crimp, where the rubber line is connected to the metal tubing is low grade aluminum. Over time and repeated heat/pressure cycles, the aluminum loses it integrity and ability to seal the rubber to the metal tubing, thus causing small leaks like this to appear. In my opinion, you can either live with it (cleaning it up and servicing transmission as required) or change the lines and possibly relive the same problem 80-100k miles from now.
Ask any ZR1 S10 owner about these types of lines.

The best way to determine whether they are truly leaking or not, is to wipe them down and see if the fluid reappears after a few days. No need to drop the pan unless filter is due for replacement.

BTW, never flush your transmission!
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So after talking to my dealership I found out that they have an extended warranty on those lines up to 70,000 miles. They also have a lifetime extended warranty on the fuel filler neck, which I guess is what has been causing the regurgitation issue. Either way, it shouldn't cost me a penny for anything besides the transmission fluid change.

As to the transmission fluid flush issue, can you elaborate at all on that? I've heard it mentioned before and never really understood the reasons why it is bad.
 
I guess the term "flush" could have multiple meanings. I have run across a few people who only began to have transmission issues immediately following a pressurized flush (not jeep owners).
I see no reason why this type of maintenance would be required as long as proper fluid and filter change intervals are followed. ATF, by nature, has high levels of detergents to mitigate varnish and deposits. There is no justification that these "flushes" remove anything harmful to the performance of your transmission. Just my opinion
 
Understood, and you definitely aren't alone in that opinion. I've heard it from quite a few people. I've also read many horror stories that people have had immediately after transmission flushes. Thanks for all the info, I'll definitely be going with the pan drop and filter change.
 
Your not alone in this one. I also noticed my lines leaking the other morning, and plan on taking it in for a better look. I have a 2011 sport with 40,000 on it and had my transfer case and diff fluids changed about 2,500 Miles ago. I wonder if this is a common assurance.
 
Blacksunshine said:
Your not alone in this one. I also noticed my lines leaking the other morning, and plan on taking it in for a better look. I have a 2011 sport with 40,000 on it and had my transfer case and diff fluids changed about 2,500 Miles ago. I wonder if this is a common assurance.
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Yeah, I'll let you know what the dealership does for me tomorrow.
 
Well, after a full day at the dealership they replaced my tranny lines and fuel filler neck for free under the extended warranty. The tranny fluid change and filter replacement cost me $219 total! Ouch! Lol
 
How bad of a leak did u have mine is dripping on my tie rod that's how I noticed it. You think I should take care of it now.
 
Blacksunshine said:
How bad of a leak did u have mine is dripping on my tie rod that's how I noticed it. You think I should take care of it now.
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Mine was about the same. I don't think it's something that's going to ruin your Jeep tomorrow, but I would definitely bring it in sooner than later. My theory is, I'm going to have to spend the money regardless, why wait and possibly have to spend more?
 
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