Transmission Line Leak 2010 GMC 1500

[dprc]

I have started to have a leak in my 2010 GMC 1500 5.3. Seems to be where the metal clamp meets the rubber line in the middle. Anyone else experience this? 31,000 miles...out of warranty...not happy.

[russellb]

I just fixed this problem myself and its quite easy. I went through the same warranty woes with gm as well. Whatever you do, don't by stock replacement lines cause it will do it again. I got stainless lines made with Teflon liners inside made at napa. The line is cheap but the compression fittings aren't. I did one transmission line and one auxiliary oil cooler line for $200. The stainless lines will handle 500 farenheit and I've been informed that stock gm lines handle 100 farenheit. Stock gm lines fail near the crimped rubber section. I simply took a mini pipe cutter and cut the lines right tight next to the crimped ends on the old line, cleaned the metal lines with sandpaper and installed the new lines. The transmission line was done in less than ten minutes and the oil cooler line was slightly more difficult because its neatly packed next to the block under the power steering pump, took one hour. Make sure the fittings are tight and wipe away any residue left behind to make sure job is flawless with no leaks. I only replaced the lines that were leaking but I expect to do the same to the other ones as they wear out.

[thisbudsforyou]

Same happened to my 08 around 40000 miles. Picked up some rubber hydraulic hose and a couple hose clamps at the part store. Probably less than 10$ to fix it. Has 80,000 on it now and hasn't leaked a drop. Had to use a tubing cutter to cut the ends off of the old hoses before sliding the rubber hoses on.

[mike94silverado]

I agree with doing an aftermarket fix, as the lines will just leak again but with 31k you are out on time, you may have a case to call gm customer service....

[russellb]

I agree with national miner. That would be something to bring to gms attention, 31000 and it already leaks tells me that the factory crimped hose was poorly made and should be in the best interest of gm to fix it.

[CapitalTruck]

Are those compression fittings on the end of the stainless steel braid?

[russellb]

Are those compression fittings on the end of the stainless steel braid?

Yes they are compression fittings, and they were the expensive part. Each line has a crimped on male thread on each end with a crush sleeve and corresponding female thread. Crank them up tight and that's it. The lines have a Teflon lining inside and are good for 500 farenheit and over 300 psi. The line is relatively inexpensive but the compression fittings are a little dear. The compression fittings on the big line are $65 each and the fittings on the small line are $14 each. The big line was $6.50 and the small line was $5.47, 4 crimped ends was $12.00 for a grand total of $195.47 including tax. I would only use rubber line and hose clamps as a temporary fix only simply because you can have a rubber line good for say 500 psi but its the holding power of the hose clamp that can be the problem. Unless the metal lines the hose is slipped onto are ribbed, which in this case they are not. So a compression fitting has the upper hand in strength in terms of the locking device.

[Chris]

For me I ran all 3 lines full -6 teflon with AN fittings.

 

Here is what the hose looks like

 

My finished product

[Sierra12_90]

I have a 2012 Sierra 5.3 and only have 54000km and have to replace the lines for $500 because they aren't covered by warranty. I'm not happy, I've only had it 4 years. They should last longer in my opinion, seems to be a common problem.

[MaverickZ71]

VERY common problem, both with transmission cooler lines and oil cooler lines. Covered by the 3yr/36,000 mile bumper-to-bumper warranty, but not the powertrain warranty. Typically, GM has known about the problem for years (we've had the same problems on a 1996, 2000, and 2009), but has done nothing about fixing it.

[Daryl LBZ]

For me I ran all 3 lines full -6 teflon with AN fittings.

 

Here is what the hose looks like

 

My finished product

Where'd you get your line and fittings at?

[Chris]

Where'd you get your line and fittings at?

Local hydraulic shop

[Daryl LBZ]

Local hydraulic shop

Figures. Mine need done, just unsure of exactly what I need for lines and fittings.

[Chris]

Figures. Mine need done, just unsure of exactly what I need for lines and fittings.

Pop one out of your trans and have them match up the size and thread. I will warn you, it is not cheap. It is solid and will last longer than your truck, but you will pay for it.

[Daryl LBZ]

Pop one out of your trans and have them match up the size and thread. I will warn you, it is not cheap. It is solid and will last longer than your truck, but you will pay for it.

How the hell you get them out of the trans? I looked under there a few months ago, and it looks impossible to get them unhooked.