Hey everyone. Checking the cooler lines on the passenger side for leaks after I had the hoses replaced going to my aux cooler I noticed one of the hard lines (not part of the return line to the aux cooler) is really rusted but not leaking. I am attaching a photo. How bad would be the "replace line now" threshold? If I am there, how bad are these lines to remove and how can I find the part number of this line to order it? Thanks
Transmission Line Rust
- Thread starter ComputernerdBD
- Start date
gpking
Member
Mine looked about that bad when it ruptured on the interstate and had the underside looking like I just ran over a crowd of people like a Mustang leaving Cars & Coffee.
The leak started small, dripping ATF down in the skid plate, but I neglected it for a few weeks, which then caused it to burst.
The lines consist of 4 parts, all of whose P/Ns can be found on RockAuto.
There's two small lines with just ~90° bends which are the front set, then 2 longer lines which are the rear set.
I honestly couldn't tell you left from right. Maybe one of Mooseman's manuals has them labelled.
This is not a fun job, even for a guy like me with small hands. It took hours just futzing with the stupid "quick" connects.
Getting the clips on was very easy for me, actually getting each line to seat was what took forever.
And you also have to drop the transmission down a few inches to get the new lines on. A borescope really helps with this.
Still better than paying someone though.
The leak started small, dripping ATF down in the skid plate, but I neglected it for a few weeks, which then caused it to burst.
The lines consist of 4 parts, all of whose P/Ns can be found on RockAuto.
There's two small lines with just ~90° bends which are the front set, then 2 longer lines which are the rear set.
I honestly couldn't tell you left from right. Maybe one of Mooseman's manuals has them labelled.
This is not a fun job, even for a guy like me with small hands. It took hours just futzing with the stupid "quick" connects.
Getting the clips on was very easy for me, actually getting each line to seat was what took forever.
And you also have to drop the transmission down a few inches to get the new lines on. A borescope really helps with this.
Still better than paying someone though.
Mooseman
Moderator
Or cut out the rusted section and use brass compression fittings and brake line. We currently do this with the low pressure power steering line.
x2^
For anyone contemplating replacing their Transmission Cooler Lines with a GM OEM Set… This might seem like a common sense, “basic small mechanical” repair… but it definitely is NOT. This video by “Klowny” (Yes… He likes to ‘Clown around’...but is a Very Good Mechanic) is just about as complete as you can find that shows the idiosyncrasies of this maddening Transmission Sealing Connector. He well describes How the clip to fitting works… How to extract it…. and How to re-install the clip without losing your mind. One last suggestion I can make from personal experience is to Install the New Lines… and New Fittings if needed (probably not) and attach the connections at the 4L60E Transmission In and Out Lines FIRST.
This is the real trick to the job that should be done before attaching the outer lines to the Radiator Fittings in order to overcome the strange mechanical dis-advantage that will happen if you install the lines on the Cooler before doing the close in work inserting the two lines into the two fittings on the Passenger Upper Side of the 4L60E and then performing the re-clipping actions needed to ensure that the lines are correctly inserted.
The line-lock swaging on the ends of the two metal pipes need to be pushed deep inside of the fitting so that BOTH spring locking Clips have actually locked the line securely inside of the fitting in front of the swaged line. For just a few Buck$ ... Harbor Freight sells the Indispensable Small Hook Tool Kit that will save you hours of extra work trying to dope out how to get the Old Clips off and the New Clips in place WITHOUT OVER-STRETCHING THEM TO THE POINT OF BEING TOO LOOSE:
And if instead… the idea is to splice in the intermediate lines with an alternative length of flared Steel Tubing and-or a combination with High Pressure Rubber Hose… The Splice-Lok System or some similar designed repair kit will do the job nicely… just Don’t Use This Kit on any Brake Lines:
As an alternative… here is “Klowny” again… describing how to perform the tube cutting and re-flaring needed to create your own seal-able Flared Tubing of the necessary lengths and the new fittings to reliably secure the lines together and safely contain the fluids they transport:
For anyone contemplating replacing their Transmission Cooler Lines with a GM OEM Set… This might seem like a common sense, “basic small mechanical” repair… but it definitely is NOT. This video by “Klowny” (Yes… He likes to ‘Clown around’...but is a Very Good Mechanic) is just about as complete as you can find that shows the idiosyncrasies of this maddening Transmission Sealing Connector. He well describes How the clip to fitting works… How to extract it…. and How to re-install the clip without losing your mind. One last suggestion I can make from personal experience is to Install the New Lines… and New Fittings if needed (probably not) and attach the connections at the 4L60E Transmission In and Out Lines FIRST.
This is the real trick to the job that should be done before attaching the outer lines to the Radiator Fittings in order to overcome the strange mechanical dis-advantage that will happen if you install the lines on the Cooler before doing the close in work inserting the two lines into the two fittings on the Passenger Upper Side of the 4L60E and then performing the re-clipping actions needed to ensure that the lines are correctly inserted.
The line-lock swaging on the ends of the two metal pipes need to be pushed deep inside of the fitting so that BOTH spring locking Clips have actually locked the line securely inside of the fitting in front of the swaged line. For just a few Buck$ ... Harbor Freight sells the Indispensable Small Hook Tool Kit that will save you hours of extra work trying to dope out how to get the Old Clips off and the New Clips in place WITHOUT OVER-STRETCHING THEM TO THE POINT OF BEING TOO LOOSE:
And if instead… the idea is to splice in the intermediate lines with an alternative length of flared Steel Tubing and-or a combination with High Pressure Rubber Hose… The Splice-Lok System or some similar designed repair kit will do the job nicely… just Don’t Use This Kit on any Brake Lines:
As an alternative… here is “Klowny” again… describing how to perform the tube cutting and re-flaring needed to create your own seal-able Flared Tubing of the necessary lengths and the new fittings to reliably secure the lines together and safely contain the fluids they transport:
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Hey everyone. Thanks for the tips, I don't want to chance it with hoses so I am having them replaced with OEM lines. I was quoted a good rate to do it in, so I am having it done professionally. I am going to prime/paint these first so they don't rust also.
Also on another somewhat related note, I drove the truck 200 miles on a trip to southern NJ (since nothing was leaking and the rust was there and somewhat unchanged over a year or two, the truck was good to go) and noticed that same quick disconnect to AN setup with this kit started to sweat at the teflon threaded fitting. I was checking it again like I was doing daily before this trip for 2 weeks because I was concerned about the AN to threaded part. While the AN part was completely dry, the teflon looks like it started to leak and it hasn't in over a year. Driving into NJ where I normally go is always crazy for me but it seems the abuse of driving it almost 5 hours today in hard stop and go, high speeds to stay with traffic and hard acceleration up to 6000 rpms (tailgater collision avoidance and throttling up to get on highways) along with the fact it was 90 degrees out was too much and caused pressure spikes which were too much for the teflon? I just drove it another 30 miles at slow to moderate speeds at very low RPMs and I cannot reproduce this leak at all under those conditions. Completely dry after I wiped it after finding it wet the first time.
Since this is not the first time this has leaked there, I found part FPE-AN920-06DBK online and plan on replacing this aluminum fitting and the clip fitting in the radiator with this and a 90 degree -6AN fitting at the radiator. Would this work and possibly be more secure than the clip and additional threaded part? Do we use thread tape on this part or does the O-Ring do it all? Example photo attached but does not show the current sweating fluid issue. Thanks
Also on another somewhat related note, I drove the truck 200 miles on a trip to southern NJ (since nothing was leaking and the rust was there and somewhat unchanged over a year or two, the truck was good to go) and noticed that same quick disconnect to AN setup with this kit started to sweat at the teflon threaded fitting. I was checking it again like I was doing daily before this trip for 2 weeks because I was concerned about the AN to threaded part. While the AN part was completely dry, the teflon looks like it started to leak and it hasn't in over a year. Driving into NJ where I normally go is always crazy for me but it seems the abuse of driving it almost 5 hours today in hard stop and go, high speeds to stay with traffic and hard acceleration up to 6000 rpms (tailgater collision avoidance and throttling up to get on highways) along with the fact it was 90 degrees out was too much and caused pressure spikes which were too much for the teflon? I just drove it another 30 miles at slow to moderate speeds at very low RPMs and I cannot reproduce this leak at all under those conditions. Completely dry after I wiped it after finding it wet the first time.
Since this is not the first time this has leaked there, I found part FPE-AN920-06DBK online and plan on replacing this aluminum fitting and the clip fitting in the radiator with this and a 90 degree -6AN fitting at the radiator. Would this work and possibly be more secure than the clip and additional threaded part? Do we use thread tape on this part or does the O-Ring do it all? Example photo attached but does not show the current sweating fluid issue. Thanks
