A/T Fluid Change

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Would it be possible to change your automatic transmission fluid this way?

1. Disconnect the line at the transmission cooler.
2. Attach a hose to the return line and the other end to a 5 gallon container of fresh fluid.
3. Let the other opening drain into an oil pan.
4. Start the car and allow the fresh fluid to flow from the 5 gallon container through the system and old fluid will be pumped into the drain pan. Shut off the vehichle when the 5 gallon container is close to empty.
5. Reconnect the hose to the transmission cooler.
6. Check the fluid level and top off if needed.

Do you think this would work?
 
The ATF pickup is in the pan(sump). The return hose will not have any suction. So, it won't work.
 
Hmm ..probably ..but not at the rate that it will be pumping out at. This came up before from another poster. You're trying to get a seamless exchange.

The only way that I think this would work would be IF you could get two sealed containers that you could attach the lines to. An empty one would receive the outgoing fluid. This would pressurize the sealed bucket. A line from that bucket would then transfer the displaced air into the full bucket of new fluid. That air pressure would push the new fluid into the transmission. I imagine elevating the buckets would aid in the flow after the siphoning effect is established.

This is how some fluid exchange systems work ..except that they have a piston separating the new and old fluid. As the old fluid is purged ..it forces the piston ..which pushes the new fluid in.
 
OK
I think I understand now. There is no vacum on the return to the system. Pressure pumping out, so it needs to be a closed system. OK. Guess I will leave the ATF flush to the professionals.
 
No, don't give up. If you're willing to do what you originally planned, it's just as easy another way.

Here's the fluid change method I use on all my cars that don't have a torque converter drain plug:

1. Pull the transmission dipstick (located near the firewall in most cars). Fresh fluid is translucent and cherry red. Some darkening is normal, but if it is reddish brown or mustard color and smells like burnt varnish, it is worn out.

2. Make sure the fluid is warm.

3. Remove all pan bolts except for the corners. Remove the bolt from the lowest corner, then loosen the other corner bolts a turn or two. Carefully pry the pan to break the gasket seal at the lowest corner. Drain mostly from this corner. With good technique you can avoid or at least minimize the red bath.

4. Remove pan. Inspect the pan before cleaning. A small amount of fine grey clutch dust is normal. However, if you find metal shavings, there has been transmission damage. Remove all old gasket material. Clean the pan and magnet with solvent and wipe dry so there is no harmful residue. Shop air can be used to clean the magnet. Hammer back any pan damage from previous overtightening.

5. (Optional) Drill hole in pan at low point and install a drain kit available from most auto supply houses. Make sure the kit protruding inside the pan doesn't interfere with anything on the transmission.

6. Replace filter.

7. Position gasket on pan. Some gaskets have four holes slightly smaller than the rest to allow four bolts through the pan and through these smaller holes to hold the four bolts and gasket in place.

8. Hand tighten pan bolts in a criss-cross pattern. After that, use a torque wrench to tighten bolts to proper ft-lbs as per manufacturer.

9. Refill the transmission using only the amount shown as “refill capacity” in the owners manual (or an equal amount that was drained), using the type of fluid specified for the vehicle.

10. You now have replaced the transmission fluid and filter according to manufacturer’s requirements. Fluid is changed in the pan only.

You can stop here and go to Step 17 if you just wanted a regular drop-the-pan fluid change. For a complete exchange of the fluid (including transmission body and torquer converter) continue with the next steps.

11. Obtain the total system capacity of the vehicle from the manufacturer. Have this amount - plus a bit more - of fluid readily available.

12. Disconnect the oil cooler line from the oil cooler. Tickle the ignition to find the flow direction. Direct the stream of fluid toward a receptacle. It is better to use a clear length of hose with a shoplight laying next to it so you can see when all the old fluid has left the system.

13. Start the engine, let it idle to pump out old transmission fluid until you start seeing air bubbles.

14. Stop the engine. Refill transmission through fill tube with fresh fluid - same amount as pumped out (usually about 2-3 quarts).

15. When either the fluid color brightens or the total capacity has been replaced, shut the engine off and re-attach the oil cooler line. All transmission fluid has now been changed.

16. Button everything back up. Clean up the mess.

17. Recheck the fluid level. With the car on level ground, set the parking brake and the transmission in “Park” or “Neutral.” Let the engine idle for a few minutes. Shift the transmission through all detents, pausing momentarily at each position, before returning the lever to “Park” or “Neutral.” Check the fluid level again and check for leaks. Refill fluid so it is slightly undercharged. This way it can be properly checked and topped off after a long drive.
 
Here's a simple method to make a extractor.

I had a clear/translucent bucket. It has a top that snaps on (also has a handle). I drilled a hole on the top and attached a 1.5'' PVC pipe fitting, on the opposite side of the top I drilled a small hole and attached 2 1/4'' barbed fitting with a connector, so that one is on the top and the other on the bottom. I also bought 10' of clear 1/4'' hose and cut a small piece to that the bottom barbed fitting to the bottom of the pail. Put the lid on and connect the top barbed in to what you want to suck/pump out. Insert your shop vacuum in the 1.5'' PVC connector and the fluid will be sucked through the hose and into the pail.

Total cost about $6. The shop vac never ingests anything since it's separted.
 
Kestas,I do the same and call it purging.
smile.gif
 
Thanks. I have a drain plug and I have been doing drain and refills every 24,000 miles. I might experiment a little bit. My wife needs some new reasons to complain!
 
For those doing the Kestas method, I think that a bit of anxiety can be removed if you move #12 up to between #2 and #3. You may as well have a near empty pan when you pull it down.

Dagwood ..funny how they still let you know that they care (my wife has a sweatshirt that says "I yell because I care").
 
quote:

Dagwood ..funny how they still let you know that they care (my wife has a sweatshirt that says "I yell because I care").

Oh...so she really cares!....I will have to share this new information!
 
i have done it as described with an '01 montero...

disconnect in/out lines at oem cooler. in extended to catch bucket, out extended to bucket of clean fluid. start engine. wait. done. paraphrased a bit, but essentially the process.

perhaps there's something unusual about the plumbing in my vehicle?
 
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