Flame Red

I thought I would post how I flushed out the tranny fluid on my '15 A8 to Mobil 1 Synthetic LV ATF HP without dropping the pan. I hate taking baths in auto tranny fluid myself. Been there, done that. Plus the rear bolts on this pan are super difficult to remove if you want to drop the pan so I wanted to avoid that like the plague. I hope other that like to do things themselves will find this as some use as I posted many questions but never got a response with the answers.

If you want to Flame me like so many people seem to like to do on this forum these days, please just don't, move on and find something else to flame. Go spend your $ at a Stealership to do this.Yes, it is not 100% fluid exchange. TIme to complete was about 3 hours. No mess! No tranny fluid bath!

You will need 11 quarts of Mobil 1 Synthetic LV ATF HP to do the double flush. I found the cheapest price was at Summit Racing for 12 quarts shipped. This is for a double flush. If you want to do just a single flush, then six quarts is all you need.




You will need the following tools:

• A Mityvac Fluid Evacuator
• A Fluid pump for a quart container.
• A piece of vacuum hose
• An Auto Trim Tool Remover
• A long 90 degree pliers
• A spring clamp
• Some shop towels.

Procedure

• First, jack up the car as high as you can get it. I have a Quick Jack which is wonderful!
• Examine the underside of the A8 and on the Pan you will see the factory painted a Green Dot on the bottom of the pan. Above the dot on the top of the tranny body is the filler hole.

• Here you can see the Filler:

• It is very hard to get your hands in there - the exhaust pipe is in your way, so you will need a long 90 degree pliers and auto trim tool to get the job done unless you have very small hands.
• Thoroughly clean the area to remove any dirt! There was a ton of road grim there and you don't want that crap going in the tranny!
• Use a Trim Tool to pull up on the top plunger push pin that unlocks the filler. You are just lifting it a little, not removing it!!!

• Use a 90 degree pliers to gently wiggle out the filler cap. Don't damage the o-rings!
• You will find that the Mityvac hose will go to the bottom of the pan, no interference! No one would tell me this fact. I marked the hose with a sharpie so I would know when it was fully inserted. I used the pliers to feed the hose all the way in. I then used a spring clamp to hold the hose so it would not accidentally pull out.

• Start the machine. It will take a while and pull out a little over 5 quarts. Everyone told me when you drop the pan, only 4 quarts came out. I measured super carefully twice and both flushes it was a little over 5 quarts.
• Do not trust the markings on the side of the Mityvac - they are way off. Carefully dump the oil oil into a Mobil-1 jug. I put a sharpie mark exactly where the bottle was full before I started using the new fluid.
• I then pulled the hose off the Mityvac and coupled it to the hand pump to use the same hose to put in exactly what came out.

• If you are doing a single flush, you stop here. I did a second flush and after filling the exact amount that came out, I ran the car on the lift for a while to let the new oil mix with the old.
• I repeated the procedure and the same amount of oil, a little over 5 quarts came out.
• I use the 90 degree pliers to replace the filler cap, and pushed the locking thingy down using the auto interior tool.
• I highly recommend driving it and bring it up to proper temperature and do the GM recommended fluid level check. Mine was right on.

Good luck and I hope this information is helpful to others. My A8 was replaced with 100 miles on the clock when I first got it. I have been running a Range and only recently once got the dreaded shudder. A short drive did not seem to produce any difference in Tranny shifting. Next weekend I'll be putting a few hundred miles on it. Most people say that it takes a few hundred miles to notice the difference.


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Oskee

Nice write up, and thanks !

Tinkertech

Tinkertech

Flame Red

Mityvac 7300 PneumatiVac Air-Operated Fluid Evacuator

There are many models. I just have a large compressor. It is great for other cars where it is the only way to change the oil withour taking thw whole bottom out of the car.

A electric fluid transfer pump would work I would think. I think any hand pump with a skinny stiff tube will work if you have the endurance. Just a lot of fluid to come out if you are doing it by hand! Especially of the fluid is cold. Good exercise, but might give you cardiac arrest! Just make sure you get a long enough tube so you don't have to pump while under the car on your back!

Tinkertech

Do you know what size the opening of the fill plug is or what size hose you used?
I really don't want to jack the car up and get everything ready just to find out I have the wrong size hose.
Also a question on your Mityvac 7300. What is the CFM and PSI needed to run this unit? Also when you shut the compressor off does the unit hold a vacuum or do you have to run the compressor all the time while removing the fluid?

3 Z06ZR1

Nice write up I have 6,000 miles on my 2017. I called in to the dealer and told them about the TSB for this and went in 2 hrs later they flushed and filled me with the M1 lv.
No charge!

Tinkertech

Flame Red

It is the tube that came with the Mityvac, 0.23" OD I believe. I did not measure it, but the plug looks like it was about .75" in diameter, but I am just guessing.

Sorry, no idea.

My compressor only cycled once every 10 minutes or so. You got to leave air running through the Mityvac or you will never get finished. Mityvac does hold a vacuum but not for long and it would only dribble out without sufficient vacuum.

My tranny was replaced with 100 miles on the clock. Last December, I noticed there were some "clunks", but I cannot isolate where they were coming from. I did have the typical A8 shutter twice since last December, but it would never do it for the dealer. I hate taking this to the dealer.

Tinkertech

Tinkertech

Flame Red

No fluid came out - I was not driving it. I just let it run and shift through all the gears for a while all while up on the Quick Jack. I got all kinds of weird alarms since all the wheels were off the ground. They all disappeared when it was back on the ground.

If you drive it without that plug, G forces may make it spill I suppose.

Tinkertech

Not going to drive it, just change the fluid a couple of times in a row.

Tinkertech

Flame Red

Don't recall. I bought a generic at a local auto parts store many many years ago. Back then they sold it by itself, now they seem to come with the plastic panel removal tool sets.

jimmie jam

Excellent write up, thank you.

Tinkertech

Hello Flame Red,
Worked just as advertised! No mess at all, love it!
I used a Mityvac 7201, with this model you can pull out the fluid and put back in the new ATF. I was also able to use the large 10mm hose all the way, helps to speed up transfers. Had to buy extra hose, factory one is too short.
How long did you run the car to mix the old and new fluid before the 2nd drain?
When you set the ATF level what temp. was the Transmission Temp gauge using the DIC reading? The manual says the temp should be between 85 and 113* F. Sounds low compared to the way other car manufactures measure theirs.
Great write up.

FYREANT

Ron_Attleboro_MA

There is additional info on YouTube titled: "Camaro, Corvette, Cadillac 6, 8, and 10 Speed Auto Trans Fluid Level Check - No Dipstick", from John Kelly of Weber State University. He states the temp to be between 131 and 149 degrees when checking the fluid level on a Corvette A8.

Thanks guys.
Ron

Tinkertech

According to my 2017 GM Service Manual the trans temp ATF fluid measured at the DIC should be between 85 and 113* F when you check the level.
My C7 never gets above 137* F just driving around the city.
Those higher numbers are for the other A8 cars.