I guess I am in the minority. I am a big fan of flushing, I think it's the best and quickest way to get all the old fluid and particles out of the system.

My procedure..

1. Get 16 quarts (4 gallons) of desired new ATF
2. Slightly overfill transmission by 3 quarts through the dipstick tube. Overfilling will not hurt the trans in this short time.
3. Disconnect drivers side transmission cooler hose from radiator
4. Find a bucket that is deep enough and can fit under your raised car. You are going to mark out 3 quarts and if you can, a 6 quart line.
5. Place drivers side trans hose in bucket
6. With an assistant observing, Start car and drain old dirty fluid in 3 quart increments. Idea here is to not run the trans dry, not good if you do.
7. Stop engine and refilling with 3 quarts through the dipstick tube.
8. Continue cycle until transmission fluid runs out clean
9. Drain and drop fluid pan
10. Replace filter, reinstall pan and add correct amount of fluid.
11. Bring to operating temp and run through gears.
12. With it at operating temp and on level ground. Check the fluid level add if necessary.
13. If overfilled disconnect the drivers side transmission cooler hose from radiator and drained in small increments until correct level.

I've done this several times for years with my various w123 and w126 models I've had for my standard trans maintenance. Just remember you don't want to run the trans dry.

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1983 123.133 California
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