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Transmission Fluid Change

Discussion in 'Chevy Suburban Forum (GMC Yukon XL)' started by makthenif, Aug 23, 2009.

  1. Jimmiee

    Jimmiee Epic Member 5+ Years 1000 Posts

    If you have a transmission shop close by they will have lots of them laying around as they come in the kits and most shops have extras. Also, there is an O ring inside the fitting that also comes in the kits. Again, a tranny shop will have plenty on hand. I'm pretty sure most auto parts stores won't have the clips in stock but who knows. It is a good idea to always replace the clip because if it's a little stretched you run the risk of the line blowing off running down the freeway. Believe me, that's when it will happen! <G>
  2. Jimmiee

    Jimmiee Epic Member 5+ Years 1000 Posts

    Here's a picture of the fitting and how it's laid out:

    Attached Files:

    • Kool.jpg
      File size:
      12.1 KB
  3. jbeall

    jbeall Rockstar 100 Posts

    I think I'll try this procedure on my Bonneville first. If I'm going to mess anything up, I'd like to mess it up on the Bonneville rather than the Yukon XL.

    Although, naturally, I don't *want* to mess it up either place :)
  4. Z07

    Z07 Member

    Wether you drop the pan or open a line to change the fluid, a pump like this one will make it an easier job. If you start with clean fluid in the pan the flush will take fewer quarts and if you want to drop the pan and change the filter pumping it out will help avoid the big splash. It's also helpful on diffs and t-cases.
  5. jbeall

    jbeall Rockstar 100 Posts

    If I'm going to drop the pan, how would the pump help? Put it down the transmission fluid dipstick and pump out as much as you can before dropping the pan?
  6. Z07

    Z07 Member

    That's the idea. I've never enjoyed the pan of ATF draining out and over one edge trick.
  7. bazar01

    bazar01 Member 2 Years 100 Posts

    I also bought this adapter from Summit Racing and a clear hose from HD and getting ready to flush the ATF.

    I have a question.

    What do I do with the return line when I disconnect the top tubing from the radiator? Do I need to plug the open end? Will ATF leak out from the metal tube? Will it suck air? Or just leave it open while draining the ATF from the adapter fitting coming out of the cooler?


  8. bazar01

    bazar01 Member 2 Years 100 Posts

    I am getting ready to do the fluid flush today. Anybody knows what to do with the metal upper return line from cooler? Do I need to plug the metal tubing or just leave it open and just let the fluid come out of the Hayden fitting adapter thru the hose and container? Thanks.
  9. janikphoto

    janikphoto Rockstar 3 Years 100 Posts

    I didn't read all three pages of posts, so this may have already been covered, but... be sure to clean the pan when you remove it! Get all the gunk off the inside of it, because that magnet collects a ton of shavings during normal use over time.
  10. bazar01

    bazar01 Member 2 Years 100 Posts


    Well, I really did not plan on dropping the pan this time. I just wanted to remove the old fluid and replace with new. I will drop the pan after another 5k miles. Just wanted to make sure the transmission will be ok after the flush.

    Got it done this morning. I removed the top metal return line on top of the cooler and attached the Hayden fitting with a clear hose attached to it and ran it to a clean 5 quart motor oil container. I also attached a hose to the metal line that i removed from the cooler and ran it to a bucket just in case it leaks fluid. (This line did not leak fluid at all.) Turn the ignition ON and ran the engine until the old fluid started flowing out thru the hose and into the 5 quart oil container and stopped the engine at the 2 quarts mark. Filled the transmission with 2 quarts of new fluid thru the dipstick tube. Empty the dirty fluid container into a used oil container. Turn the engine On once again and drained 2 more quarts at a time then fill until 14 quarts total have flowed out. Pulled the adapter fitting and hoses, put the spring clip back on the fitting and reinstalled the return line. Replace the plastic retainer to secure the spring clip. Turn engine ON, shift to reverse, neutral and drive a few times, then checked fluid level with engine running. All good. Test drove vehicle and shifted smooth with no issues. I will drive maybe another 5k miles then drop the pan and replace filter and clean pan.

    Before dropping the pan, it is better to suck the fluid first through the dispstick tube with a $8 suction pump you can buy from Walmart and this will make removing the pan a lot easier with very little fluid left to spill. I tried it and it worked.

    Flushing.jpg Hayden Fitting Adapter.jpg Return line empty.jpg
    Last edited: Feb 24, 2012

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