DIY: B6/B7 S4 transmission fluid change

Ok so there have been some posts on changing the trans pan filter and gaskets along with the fluid.

Here is a brief over view to help you out. First off there are several fluids that you can change to. But if your not beating the car up at the track. I would just use the OEM fluid from the dealer. Make sure you give them your VIN cause there are 2 kinds of fluid. Some cars get type A and some get Type B. The transmissions seem to be scattered between the years and I can’t seem to nail down witch it witch. So make sure to check with the dealer.


So keep this in mind when you are setting the car up either on a lift or on your garage floor. If you are on the garage floor it will be scary being under the car wile it is running so just know that[o_o]. This might be something you want to pay to have done if you don’t feel comfortable being under a running car.

OK so to do this your self you will need

T27 Torx bit
L shaped 17mm Allen key
6mm Allen key
1.5 feet of plastic tubing (you will see from the pic’s)
2 drill bits one for the tubing one for the air hole (look at the pic’s you will see)
Vag com and Vag cable you are going to need this for the filling of the trans
Air Compressor with air gun attachment
Drain pan
obviously a way to get the car up in the air

Here we go. Get the car up in the air as far as you can if it is on jack stands. Make sure the car is Level.

When you get under the car you will see 2 black pans. One furthest to the front of the motor is the oil pan. Keep looking back you will see the trans pan

Here is what the pan looks like

Ok as you can see there is 2 plugs on the pan. Use the one labeled Drain only. It should be a 6mm allen key. Just remove it and let the fluid run out…now that the fluid about 3-5 quarts have come out there is still some in the pan. So what I do is to loosen all the bolts about 75% of the way. Then start taking out the bolts closest to the front of the car all the way back to the back. This will start the pan to lean forward lowering the front. Doing this will allow all the fluid in the pan to drain threw the drain only hole. Other wise you are going to have fluid on you if you try to drop the pan.

Now if your not changing the filter. Just put back in all the bolts you took out back in and fill it back up. If you are replacing the filter (I would suggest it.) you are going to drop the pan. BE CAREFULL trans fluid is still going to drip out slowly from all over the place in the trans. Not only that but when you take out the filter there is going to be more fluid. So make sure you get a catch can that is big enough to cover the area 100% under the trans pan you are going to need it.

Replacing the filter is easy just pull down and replace. Make sure the O ring is still in place.

OK so now lets look at the trans pan. Don’t worry about the dimensions of the trans pan in the pic it is just a reference pic

Ok so in the pic above you can see to the far right. There is a tower with 2 flaps on it. It is like a big hollow T. The tower is the exact height for where the max fluid level should be. Any more fluid will result in the fluid going over the top part of the fill tube and back out the fill hole.
As you can see the blue part I drew in was to see how the tube would enter the pan area.

Also you will see the magnets check these for any metal and clean if needed. If you do see a good amount of metal then take pic’s and asses if a rebuild may be necessary.

ok now the the next part put the filter back in and button the pan back up and get your 17mm Allen key out and remove this bolt. (I removed it before I put the pan on but that is up to you)

Now is when it gets serious. You need the car ready with the Vag com in the car. Then you need your bottles of fluid prepared.

The deal is you need to pump fluid into the pan from underneath the car. Now Im sure there is some 500$ tool you can get from Audi to do this or you can make something to push fluid up threw a fill tube that needs to go threw the hole where you removed the 17mm Allen bolt up into and threw the fill tube in the trans pan.

So I didn’t want to spend any money on something I might not use again. So I just came up with this idea.

As you can see I took the bottle drilled a hole in the cap and one at the base of the neck. You take off the cap and drill a hole just small enough where you need to jam the tube threw it and push the tube to the bottom of the bottle. only do this to ONE cap after the bottle is empty just unscrew the cap (with the tube in it still) from the empty bottle. The cap and the tube should STAY TOGETHER AND STILL IN THE FILL HOLE IN THE TRANS PAN. Then screw the NEXT full bottle up to the cap

OK in the next pic you can see how you are going to pressurize the bottle

As you can see. you are taking your compressor line and hooking it up to a air gun. The air gun attachment then goes into the hole you made at the base of the neck.

When you introduce air into the bottle the pressure in the bottle will push the fluid from the bottle UP threw the tube and into the trans above.


Start out putting in 3 quarts before you worry about starting the car and checking the trans temps. DON"T START THE CAR WITH NO TRANS FLUID

To get the optimal amount of fluid the trans temp needs to be between 32C and 34C. ANY lower or higher then the temps shown will result in the wrong too little or too much fluid.

So you need to start the car fire up the VAG com in the trans Module part. Then look at the temps. the trans will stay at about 32C for a while so you have about 5 min to fill. If you take too long the temps are too high and the fluid has thinned out and you will under fill it. Be quick

NOTE. You will know the fluid level is full. When you can’t add anymore fluid. When you add fluid and it just over flows back out. You know you’ve added the proper amount.

You will need to add about 5-9 quarts if you change the filter. LOTS of fluid will seep out that you don’t see. So even tho it might look like you only took out 3-5 quarts lots more seems to come out

I took off the fill hole allen bolt and put in the tube before I reinstalled the pan. This way I was sure to have the tube in the proper spot. From there I never needed to pull the tube back out till I was done cause I just removed the empty bottles from the cap and tube.

Also compressor pressure is important. But you need to know your compressor. it seems what is 25psi on my gage is not the same on other peoples compressor gage so be careful what you set the psi to.

When filling the bottle with air. KEEP YOUR HAND ON THE BOTTOM OF THE BOTTLE. When you feel the bottom of the bottle expand down under pressure stop the pressure from going into the bottle TOO much pressure in the bottle and the bottle will EXPLODE IN YOUR FACE and you will have fluid every where. So go slow and be careful

Thanks Justin! Great DIY. I’m planning on doing mine soon.

this is an impressive post nice work here for shure