2010 Silverado Leaking Transmisson Coolant Lines

Discussion in 'Chevy Silverado Forum (GMC Sierra)' started by Backroads, Mar 29, 2013.

  1. Backroads

    Backroads New Member

    2010 Silverado 4.8 engine for the last few days I have noticed a "wet spot" about the size of a baseball under the front of the truck right behind the bumper. I first thought maybe I had splashed through a puddle or something but on the 2nd or 3rd time I raised the hood and the oil cooler lines for the transmission were wet and had a drip or two of fluid on them. The truck only has 73,000 miles and this seems a little premature to have these lines filing has anyone else had this issue?:shocked:
  2. j cat

    j cat Epic Member 5+ Years 1000 Posts

    I would locate exactly where its leaking. could be coolant not dexronVI.
  3. RayVoy

    RayVoy Epic Member 5+ Years 5000 Posts

    White cloth, or paper, might help. The tranny fluid is red, the engine coolant is orange, or green.
  4. TRPLXL2

    TRPLXL2 Epic Member 5+ Years 1000 Posts

    Unfortunately that is not uncommon, the lines on these vehicles are paper thin and rot out relatively quickly. If you drive in salt that is killer for them.
  5. nickgiacalone

    nickgiacalone Rockstar 100 Posts

    I don't want to be the bearer of bad news but, my 2009 that I just got rid of had a very slight leak right by the fitting going into the trans cooler. I live in Michigan so we have a ton of road salt. I noticed it at about 66,000 miles.
  6. SurrealOne

    SurrealOne Former Member ROTM Winner 1000 Posts

    I'm down south in a largely salt-free area ... with a NBS truck that has 152k miles on it. While I got more mileage out of mine than others (probably due to lack of salt/brine), I just replaced my lines from the cooler, too.
  7. nickgiacalone

    nickgiacalone Rockstar 100 Posts

    150k miles seems reasonable, but every NBS & NNBS truck that I know of with 65-80k miles has had trans cooler lines replaced. (Remember, I'm talking about people in MI). We have 14 GM pickups in out fleet at work (all 2002 or newer) and everyone of them has had the trans cooling lines replaced around 70k miles.

    GM needs to do something about this. I read somewhere people were having their local hydraulic shops make lines the replacement lines with the theory that the heavy duty rubber definitely can handle the pressure, plus it will not rot. As long as it doesnt rub I could see this being a pretty good idea.
  8. SurrealOne

    SurrealOne Former Member ROTM Winner 1000 Posts

    150k mi is reasonable. However, were I up north it'd have been a fraction of that, I'm sure...
  9. TRPLXL2

    TRPLXL2 Epic Member 5+ Years 1000 Posts

    I started replaced all my hard lines with braided stainless, you can do it yourself and they're lifetime. I priced a set of PS lines at a local hydraulic line shop, they wanted several hundred dollars for two lines. Think not!! I don't even waste my time replacing the lines with factory hard lines, in my mind it's a temporary fix.

    I will say my mom's Aveo has in interesting design on it's transmission lines, they are teflon coated from the factory. Maybe GM is catching on, then again the car is made in Korea lol!!
  10. Backroads

    Backroads New Member

    I pulled up a GM blog and it seems this happens quite often and 70k does not seem unusual what really rips me is the average GM repair cost seems to be $500 to $650 this is for transmission cooler lines I would hav expected this to be at least one half of that figure. Does anyone know the line pressure we are talking about? I believe I've seen older vehicles with 2 or 3 ply rubber lines and hose clamps on these joins. I f so is that possible here?

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