The following is a brief writeup on how you can change the brake pads and rotors yourself on the B9 S4 and S5.
There are 2 different ways you can go about changing the front brake pads. You can remove the caliper from the caliper carrier, then replace the pads and rotors. The second way is to remove the caliper carrier from the spindle and then replace pads and rotors. There are pros and cons to each method.
Method 1: Removing the Caliper from the Caliper Carrier and then change pads and rotors.
-Pros: The bolts holding the caliper to the caliper carrier are easily accessible (you dont need to turn the steering wheel to gain good access) and less likely to be frozen in place with 120lbs of torque as they are lower torque bolts.
-Cons: The first time you do it this way you'll want to get rid of those specialty torx head caliper bolts and replace them with a normal bolt. Also the threads into the caliper carrier on the caliper side appear to be aluminum and soft. If you cross thread them, you're done (although you can simply thready the bolt in from the other side to try and fix the cross thread). They are more fragile.
Method 2: Removing the Caliper from the Spindle and then change pads and rotors.
-Pros: You avoid having to mess with the specialty bolts holding the caliper to the carrier. You have a solid steel thread to bolt into on that side of the caliper carrier that bolts to the spindle. Less likely to damage threads.
-Cons: You need to turn the wheel to gain access for each side. The bolts need a ton of torque.
Either way you decide to do it, here's the tools needed and the method...
TOOLS:
Method 1:
1. FastOrange hand cleaner and rags
2. Disposable 6-8 mil black nitrile gloves
3. pb blaster penetrating oil
4. wire brush
5. 13mm 12 point socket
6. socket wrench
7. flat head screwdriver
8. T30 torx bit / driver
9. white lithium grease
10. Channellock type adjustable pliers
11. 5 lb hammer
OPTIONAL: if you choose to short the brake pad sensor wire you'll want:
12. solder
13. electrical tape
14. zip tie
Method 2:
1. FastOrange hand cleaner and rags
2. Disposable 6-8 mil black nitrile gloves
3. pb blaster penetrating oil
4. wire brush
5. 1/2" drive 21 mm impact socket
6. 1/2" socket wrench with flex head
7. 1/2" torque wrench 50-250lb
8. flat head screwdriver
9. T30 torx bit / driver
10. white lithium grease
11. channellock type adjustable pliers
12. 5 lb hammer
OPTIONAL: if you choose to short the brake pad sensor wire you'll want:
13. solder
14. electrical tape
15. zip tie
PARTS:
Method 1:
1. OEM Brake Pads or equivalent aftermarket - Audi p/n: 8w0698151n
I found them here for $146 --- https://www.audiusaparts.com/oem-par...ads-8w0698151n
Note: The OEM front pads are a GF temperature rated Textar/Akebono brand pad.
Alternative pads are the RAYBESTOS SP1894EUH specialty euro ceramic pad which is a GG rated pad available for $32 per pair at rockauto
2. OEM Brake Rotors or equivalent aftermarket - Audi p/n: 4M0615301AN
I found them here for $117 each: https://www.audiusaparts.com/oem-par...or-4m0615301an
An alternative rotor is the RAYBESTOS 982153, their high performance coated street rotor available for $71 at rockauto
3. four (4) m12 - 1.25 pitch - 70mm length bolts to replace the caliper to caliper carrier bolts
Method 2:
1-2: same as above in method 1
3. four (4) replacement caliper carrier to spindle bolts (listed as one time use) - Audi p/n N91147601
TORQUE SPECS:
DISCLAIMER- These torque specs are from the B8 and most every other of the 12 audis I have owned now BUT they are not directly from the B9 S4 workshop manual so if anyone can provide 100% verification that these specs apply to this car please do. Otherwise, here are historical specs for past models.
1. Caliper to caliper carrier bolts: 30Nm or 22ftlb are the old specs for the B8 calipers BUT those calipers had a different material and way of connecting between caliper and carrier. Our calipers are much more like aftermarket Brembos, Stoptechs, etc in that they are aluminum calipers bolted directly on the carrier unlike the B8 that has a flip up style connection allowing you to rotate up the caliper from the carrier while one bolt remains connected. For our calipers I found the removal torque of our bolts to break around 60ftlb. I suspect they were torqued somewhere in the 40-60ftlb range. Stoptech recommends 40ftlb. I torqued them to 50ftlb.
2. Caliper carrier to spindle bolds: 200Nm or 148ftlb. Ive generally stopped at 120ftlb. There is a question of whether these are one time use bolts. Audi has said to clean them implying that they can be re-used but then also stated they are one time use so do what you are comfortable with.
STEPS:
Here she is:
Step 1 - Removal Of Caliper Bolts
Method 1:
1. Get either a 1/2" socket or a 13mm socket that is 12 point and hammer it onto those two specialty bolts that hold the caliper to the carrier. Get it good and snug down onto the head. Remove them.
The caliper is now free from the carrier but cannot yet be fully removed until you unhook the brake pad sensor wire and the hard brake fluid line from their brackets.
Method 2:
1. Get the 1/2" breaker bar or long 1/2" wrench with flex head and a heavy duty impact 21mm socket and unfasten the two bolts holding the caliper carrier (bracket) onto the spindle.
It will help to turn the steering wheel AWAY from the side of the car you are working on. If working in driver side. Turn the wheel full right. This gives access to those two bolts.
NEXT STEP BOTH METHODS:
Step 2- Removing the caliper
-Remove the brake pad sensor wire/plug from its bracket. Lightly place a flat head screwdriver under the plastic clip that holds the sensor connector to the bracket freeing the connector to be able to rotate 90 degrees in the braket. Once you rotate the connector 90 degrees you can slide it out of the metal bracket.
- Next remove the hard brake line from its bracket shown below. To do this simply remove the metal clip that holds the line in place by sliding a flat head onto the tip of the clip and prying away from the bracket sliding it out. Shown below is the line after the clip has been removed and freed from the bracket
- Now you can slide the caliper off the rotor and lay it down on something elevated so you do not put strain on the line.
Step 3 - Removing the rotor
This can be a really easy step or a really annoying step depending on your luck.
-Start by removing the small t30 torx screw that holds the rotor to the hub. You may want to spray some penetrating oil if this does not come off easily. If it is frozen in place you may have to drill it out. Do so. I, personally, tend to not replace these once I have successfully gotten them out. Your choice.
- Next you need to free the rotor. You may get lucky and it pops free. I didnt. If you have difficulty even after penetrating oil, give the rotor a swift bang on the rotor hat area in the area between each lug bolt hole. A few really good wacks with a 5lb hammer should break free the mechanical weld (from corrosion and compression) that has taken place.
* You may want to take a wire brush to clean corrosion from the hub area at the center bore. Some people put a bit of lithium grease there as well.
Step 4 - Replacing the pads
- the pads simply slide out towards the center of the caliper away from the pistons.
* You may want to first use a channellock pliers and a THICK rag (to protect the caliper finish) to push the pistons back into their fully retracted positions. This will make room for the new pads. Its better to do this now so you dont risk marring up the new pads doing it with them in the caliper.
- Some pads come with new retaining clips. There are 4 metal clips. Two on each end of the pad and two up at the top where the bridge would be. Replace them if you so desire.
Many new pads will not come with a metal brake pad shim that is on your old pad. Just transfer it over.
- Apply white lithium grease to any area where the pad backing plate makes contact with the caliper. Apply to the edge of the backing plate in those areas. Do not apply to the friction material surface of the pads.
REINSTALLATION IS REVERSE OF REMOVAL. Torque specs listed above. I use 50ftlbs for caliper to carrier bolts and 148ftlbs for carrier to spindle bolts. Use whatever Audi says for the B9 though. Thats just what I used.
Mike
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Originally Posted by Dardani2000
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