FK8 Brake Caliper Bushing Upgrade.

Let me preface this really quick. If you don’t know what a brake caliper bushing is, or why it’s a worthwhile upgrade then you need to read this post. Or if you do know what one is and why it’s important, you should still read this post.

While I was at Buttonwillow a few months back. I had encountered a small rear brake issue that was slightly disconcerting. This is how the story goes… As I pulled up to my pit area after 7 grueling laps. I noticed a slight amount of smoke that flowed past my window as the car came to a stop. It wasn’t an alarming amount of smoke, but it was enough to get my attention. Anyhow, I continued with my normal routine and began checking hot tire pressures. While checking the pressures I was simultaneously inspecting for smoke or some evidence of excessively hot stuff.

The driver front was fine and showed no signs of overheating. I then moved on to the driver rear. I was able to immediately notice smoke coming from the caliper and could feel a lot of heat. (more than normal for a rear brake). I quickly checked passenger pressures. Starting with the rear, where there was no sign of smoke, overheating, or malfunctioning. I moved up front and again no signs of overheating.

Now that the issue was isolated to the driver’s rear. I began going over in my head what the culprit could be. Because my car (like most every Honda) has a floating rear caliper, my first thought was there could be a pad dragging issues caused by the caliper not sliding freely on the pin and binding.

Normally, floating calipers work great and don’t require much maintenance other than re-greasing the pins. This is done every time you change the pads on that caliper (unusually 50-75k mile intervals). However, because I have subjected mine to numerous track days. There is always the potential that the grease on the pins dried up, got gunked up, or was just exposed to an elevated temp outside of its optimal operating range and caused some binding issues resulting in excessive pad drag.

Either way, I wasn’t having the greatest of days already and this was sort of the nail in the coffin for me. I had pulled my neck out of whack the day prior and it was incredibly painful to rotate my neck in any direction. Pulling my helmet on before each session and compressing my spine/neck area was nearly brining me to tears. While on track the added weight of my helmet and increased G forces I was subjecting my neck to was not a good feeling. It was even hindering my driving because I couldn’t even turn my head to look through corners. It was just too painful. The other major frustration of the day was. I had some one-year-old RT660’s that were like being on ice due to the amount of heat cycles they had been through. The 660’s were so bad that I decided to try out my two year old RS4’s (daily driving tires) and was able get faster lap times. Then on top of all that, I experienced this rear braking overheating issue and that was the straw that broke the camel’s back! I threw in the towel for the day, packed my things a drove back home to Las Vegas.

Before I decided to head out on my 350-mile drive back home I did assess the rear brake issue and found nothing that could have been causing it to overheat. I jacked up the car, and was able to spin both rear wheels freely without any resistance. I was also able to jiggle each rear pad slightly which told me there was no binding or stuck pad. Deeming the car safe for travel, I packed it all up and headed home.

On the long drive home, I had plenty of time to contemplate what I was going to do to ensure this wouldn’t be an issue for me going forward. Yes, there are a plethora of options I could do to upgrade my rear brakes. But on a FWD car brake bias is especially important and “over braking” the rear can cause all sorts of issues that will ultimately slow you down (not in a good away) around the track.

There are options out there to upgrade to a two piece rotor, or even upgrade to a larger diameter rear rotor. However, for me I felt like the issue wasn’t with the rear brakes overheating due to lack of stopping power so I wasn’t considering any of these options. Don’t get me wrong, It would be sick to have some GiroDisc rear two piece rotors. But it was hard to convince myself to spend the 800 bucks just to save a few pounds on non-drive wheel rotational mass and increased heat dissipation. Who knows though, if the upgrades I decided to do don’t fix my issues then I might end up upgrading to the two-piece GiroDisc’s in the future. So please, don’t hold me to having OEM rotors forever. If a guy wants to upgrade later then I will. For now though I feel that my rear brake setup is sufficient for me and my driving level.

Below you can see what three things I was going to do.

I decided that since I overheated the rear there was a chance that I warped that one rotor. Rather than just get the old rotors turned and resurfaced, I just purchased brand new OEM ones. I have a very weird OCD about “nothing being better than OEM”. I felt that if it went somewhere to resurface the rotors there was a possibility that they could have done a bad job and caused some sort of imbalance in the rotors. Honestly there isn’t that much opportunity to mess up resurfacing a rotor because it’s being turned on a lathe. But… for me I just didn’t like that nanoscopic possibility that someone else could potentially screw up.

Because of my trust issues I ordered brand new OEM rotors. They were 150 bucks shipped and quite honestly, I don’t even think the old ones were warped but it just gave me peace of mind.

Next were pads. I have been using the same Project Mu club racer pads in the rear since day one on this car. I have never changed them out. That’s right, I have had 10+ track days on this one set of pads. FWD cars, even heavier ones like the FK8 don’t tend to wear out rear pads as fast as a RWD or Mid-engine car. I figured that since it had been almost two years I might as well change them out. Especially since I was putting on brand new rotors. I wanted to ensure the pads bed in with the rotor properly to guarantee maximum amount of braking potential.

I opted to go with a pretty aggressive compound, the Paragon R5. Admittedly, this compound might be a bit too aggressive for the rear and could potentially cause it to lock up more easily. This would then trigger the ABS, ultimately slowing down my lap times. However, there is a lot to be gained through “brake pad tuning” so this will just be a fun experiment. Again, in a FWD platform it’s good to get that rear end rotating as you are going into the turn and this more aggressive pad might just help do that. Or it could totally screw up my brake bias and frustrate me even more. Unfortunately, I haven’t had a track outing since installing them and have no review on how they perform on track.

Below you can compare the stats between the two pads. First chart is the R5 pad. Second Chart is the Project Mu Club Racer chart. It is also worth noting that the Paragon pad is made by Winmax. It has the same specs as the Winmax W5 pad. It is also interesting that the Club Racer pad has a higher operating temp than the R5 pad despite being a bite more of a “street” oriented pad.

The third and final modification is the real upgrade and has the potential to solve my problem. Bronze/Brass brake caliper guide bushings are used to replace the rubber caliper busing that come on the car stock. The soft rubber bushing allows for caliper flex under hard braking conditions. This contributes to uneven pad ware and even inconsistent braking and pedal feel. Brass/Bronze brake caliper bushing upgrades aren’t a new thing and have been around for many, many years. It just so happens that the 10th gen Civic model was the first Honda Civic to utilize the specific style of floating caliper that uses rubber guide bushings. This type of floating caliper is more prevalent on German cars and that is why for many years there have been the brass/bronze bushing upgrade.

BMW guys have been using these bushing upgrades for years. They claim them to be a viable upgrade to ensure optimal brake performance under extreme conditions. Heck, the BMW guys (and most other German cars) also must do this on their front calipers too.

Yes, all Hondas/Acuras that were made from the 80’s up until 2015ish had floating calipers on the front and rear. (if they had rear disc) But the design of the caliper was different and there wasn’t the ability to swap out rubber bushings for brass/bronze ones. For some reason on the 10th gen civic they decided to change the rear floating caliper style and went with the “German” style ones.

Don’t get too hung up on my rudimentary explanation of the differences between the types of floating calipers and don’t hold me to specific dates/timelines. Just know that starting with the 10th gen civic and certain newer Acura’s around 2015 they decided to use a different type of rear floating caliper. It’s not a new design, it’s just new to us Honda enthusiasts.

The Bronze/Brass bushings are machined to extremely precise tolerances and don’t allow for any flex in the floating caliper. This allows the caliper to squeeze more evenly on both sides of the rotor. Resulting in better pedal feel, more consistent/predictable braking, and increased pad life.

There is downside though… There is increased NVH (noise, vibration, harshness). This is why cars come from the factory with rubber bushings that act as insulators to help absorb that NVH. Also, the performance gains and improvements won’t be all that noticeable under normal driving conditions. So don’t expect to install these bushings and feel a drastic improvement as you back out of your driveway. Lastly, these do require a bit more attention when it comes to maintenance. Unlike the rubber bushings where you can just set and forget. The Brass/Bronze bushings require more frequent service intervals especially ones without dust caps (like the Wunderladen racing ones have). Because the tolerances are so tight and there is no wiggle room these can get gunked up with dirt/debris much quicker than normal rubber bushings. So, unless you enjoy re-greasing your brake calipers every few months… I do not recommend installing these on your daily driver. I mean, you can install them on it, but they will just require more attention.

At the end of the day these bushings are only 75 bucks. Whether they make a huge difference or not isn’t that big of a deal because it’s not that risky of an investment and you can always easily revert back to the rubber bushings. But there must be a reason why so many German car enthusiasts swear by them. There is! And as more and more Hondas/Acura’s start to adapt to this type of floating caliper, I’m sure we will see this modification become more common in the Japanese car scene.

OK, OK, enough talking, on to the Installation process.

Since I’m only working on the rear brakes, I’m just jacking up the rear of the car. Below you can see the jacking point for the rear of the car (just slightly left off the muffler)

Jack it up to max height.

And place jack stands on each side. (And before someone says I don’t know what I’m doing… Yes, one of my rear tires isn’t going the correct direction. This is because at my last track day I shredded both left side front and rear tires on the titan’s (my track wheel setup) at buttonwillow and drove home on my 4 Regas. When I originally went to start my rear brake project, after jacking up the car and removing the Regas, realized that I was sent the wrong rear rotors. So, because there is more socket clearance when taking the lug nuts off with the Titan’s vs the Regas and I knew that I was going to be doing brake stuff again as soon as the correct rotors came in. I decided to leave the Titan’s on while the car sat in the garage. Phew…. I hate how the internet has become such a cesspool of negative, shit talking haters, that I actually have to write a disclaimer about why I have one of my tires going the wrong direction. But such is life and I choose to have a blog that is open to public scrutiny.

Pictures below to better help explain.

Driver rear on car.

Driver rear off car. Keep in mind that I rotate tires front to rear every half day. So, these were most likely front during the last track day.

Driver front on car

Driver front off car. Again, there is less wear because these were previously on the rear last track day.

Daily setup with 2-year-old RS4’s that ended up being quicker than the worn out 660’s this day (for obvious reasons)

Car with track wheel setup on.

Ok, enough of me trying to explain why one of my tires isn’t going the correct direction.

So the car is on jackstands now.

Anyways… Take the wheel off to gain access to the brakes. (This was also the side that was smoking at my last buttonwillow event)

No real obvious damage and you can even see that on the pad you cans till make out the writing.

Next, I use an impact screwdriver to break loose the rotor set screws.

Then it’s time to put the electronic barking brake into “maintenance mode”. For this I will be using the Autel tool. This plugs into the OBD port under the dash and connects to an app on your phone which allows you to access “maintenance mode” for the EPB.

Below is what the app looks like. Select service.

Then select EPB.

Then enter brake pad maintenance mode.

Then hit ok.

Once you have successfully entered brake pad maintenance mode (you will hear the electric motors make noise as the release) We are now going to remove the bolts that mount the caliper to the spindle. This allows us to remove the whole caliper so we can swap out the rotor.

This is achieved by loosening the X2 17 mm bolts that secure the silver part of the caliper to the spindle. See the socket wrench location below.

With those X2 17mm bolts remove the whole caliper assembly will easily slide off and you can set out of the way. This allows the rotor to easily be removed.

Usually because of rust, dirt/debris and heat cycles, the rotor gets seized on to the hub. You can either take a dead-blow hammer and hit the rotor until the impact shock frees the rotor. ORRRRR, you can do it the proper was and use the threaded holes on the rotor to thread 10mm bolts into and evenly cinch down until the rotor breaks free from the hub. (see the two bolts below)

There isn’t much force needed for this so I’m using a 1/4 inch ratchet to illustrate the fact that you can just lightly tighten down the bolts. Make sure to evenly cinch them down.

Below is what it will look like when the rotor come free.

Below you can see how the bolts only needed to slightly protrude to get the rotor broken free.

And below you can see the slight mark it made on the hub. The other hole to the top left is the one that the rotor set screw goes in.

It’s also a great idea to get a brass brush and get rid of all the rust. Sometimes if there is a large amount of rust, or debris build up and can cause the new rotor to not sit flush on the hub and this will give you all sorts of brake issues.

Since my car is new and I live in a VERY arid climate there isn’t much rust so only light brushing is needed. But, if you live in very humid, wet areas, or your car has many miles on it, you may need to use some sort of lubricant like WD-40/PB blaster and scrub a little harder to get all the rust off.

Below just for reference, you can see where the brake caliper is bolted to the spindle.

Once all rust and debris is cleaned off, you can simply slide the new rotor on and reinstall the set screw.

Now that the rotor is back on, I bolt the caliper back on to the spindle.

Now it’s time to remove the caliper from the caliper bracket (this is how we gain access to the pads and swap out the bushings.) Start off by removing the brake caliper spring. This is easily done by using a screwdriver to pry one side off. It is even possible to just use your fingers as well, but I’m trying to show you the easy way.

Once one side it popped out, the other side will simply fall out.

There are plastic dust caps that need to be popped off to allow access to the 7mm hex bolt that secures the caliper to the caliper bracket. See below, I’m using a small green flat head screwdriver to pop the dust cap off.

Below is what the plastic dust cap looks like once removed.

Get your hex socket or Allen wrench in there and remove the pin.

Below is what the pin looks like once removed. Keep in mind there are two total that need to be removed.

Now the caliper can be folded out of the way. This is how you replace just pads (make sure the car is in maintenance mode to the EPB too, unless you are swapping out pads that are very similar in thicknesses.)

Below, in the center of the picture in the rubber bushing we will be removing and replacing with the brass bushings.

Use any tool of your choosing to push the bushing out. It is very soft and malleable so it should easily come out.

Below is what the rubber busing looks like once removed.

Now, take the new brass bushing and it will easily slide in. Make sure you are sliding it in the correct way. Because it will slide in both directions but will only properly go back together with the lip oriented as pictured below. (Lip of the bushing towards the outboard side of the caliper as you can see below)

There is now a C clip that needs to be installed. It is very beneficial to have proper C clip pliers for this. It can be done other ways, but not without much frustration.

Below you can see the bushing is all installed and the C clip is properly seated in the groove of the bushing.

Here is another look of the caliper with the OEM rubber bushing removed.

Both bushings installed. You will notice that the bushings have some movement or play back and forth, this is ok so don’t worry.

It is also worth noting that the kit comes with an extra set of rubber O rings that go inside the brass bushing. This helps seal out all the elements and is consumable item (one more reason these brass bushings require more maintenance)

Now that we are ready to install new pads, we must compress the piston back in to allow the caliper to slide over the new pads that are much thicker than the worn-down ones we just removed. This is why you need to have the EPB in “maintenance mode”, because you can damage the caliper seals if you don’t fully release the EPB to allow the piston the room to go completely back in.

I just use some very large channel locks to compress the piston back in. There are specific tools for this, but I feel the large channel locks work just fine. Up to you whichever you choose to use.

Now the new pads simply drop right in. Make sure the pad with the spring is inboard. Some people choose to grease where the pad sits into the grooves of the caliper bracket.

Next, we need to lube the inner part of the bushing where the pin goes. This will allow for the caliper to easily slide and not bind. YOU MUST GREASE THIS. I used a pick to get grease far enough in and evenly spread throughout the whole bushing.

Once you have greased the inside of both bushings, reinstall the caliper and begin threading the pins back in.

Everything is almost all the way back together now.

Don’t forget to install the dust caps that are included with the bushing kit.

Reinstall the caliper spring, this can easily be done by hand and no tools should be necessary.

Now take the car out of EPB “maintenance mode” and you are ready to bleed. Keep in mind that you will need to leave the car in EPB “maintenance mode” while you do both sides. I only showed doing one side, however, I didn’t document doing the other side because it’s the same process as what I just went through.

Make sure you bleed the brakes. (I’m not going to show you how to bleed the brakes, I have gone over it many times in other posts in the blog already.) Really quick though, the proper sequence for bleeding FK8 brakes is… Front left, Front right, Rear right, Rear left. Then cycle the EPB switch on and off 5 times, then rebleed, FL, FR, RR, RL. It’s important to cycle to EPB because there is a labyrinth of small brake fluid passages in the EPB that leave many opportunities for air bubbles to get caught in.

Below is a good comparison picture of the rubber OEM bushings VS the brass bushings.

Below are some pictures I took of what the pads that came out looked like.

As you can see, much to my surprise they seem like they have pretty even ware. This leads my to believe that my brake overheating/smoking issue wasn’t due to uneven pad ware but rather just expired pads. You can also see that the pads overall aren’t in the best shape and there is some glazing. I’m sure that after 10+ track days they were done and were overdue for replacing.

Compared to the new pads I just installed.

And some beauty shot of everything 100% done.

To sum it all up. I’m sorry but I can’t give you conclusive feedback on whether these were effective during on track performance or not. This is simply because I haven’t gotten back to the track since the upgrade. I will say that this is a very common upgrade for German car dudes who frequent the track and for that reason alone I’m confident in stating that in extreme conditions these will come into their own and prove to be a beneficial upgrade for our FK8 platform. Because lets be honest, our cars are a little German any way’s right… From the Bosch ECU, to the Mahle intercooler, direct injection, and the rear sliding calipers. Our cars are almost more BMW than Honda.

For the price and ease of install I would definitely suggest giving these a try, just to see what you notice from them, especially if you are tracking your FK8. If I hadn’t done the rotor upgrade, the bushing install alone wouldn’t have taken more than 30 minutes tops. Plus, it’s easily reversible and has no real cons other than slightly increased NVH (pad squeal during slow speed stopping. like up to a stop sign) and a little more frequent maintenance interval.

I wish I was able to give a more definitive result. But because I upgraded to a more aggressive pad at the same time, it’s hard to tell if the bushings made the difference in pedal feel and brake responsiveness. Or, did the pads do that because the initial bite is better. Either way, what I can 100% guarantee is that installing these bushing will give you peace of mind that you have eliminated a weak link in you braking system. And to me, that alone is worth the seventy-five dollars that they cost.

I hope you enjoyed reading about an uncommon upgrade that (like me) you never knew existed. And, as always, I hope you learned a thing or two and gained some confidence to get out and do some work on your own car. whether or not you liked, hated, disagree, or want to know more about what you have just read, please don’t hesitate to reach out. I love to hear from my readers, so please get in contact via Instagram @Functiontheory, email me at, or simply comment on the post below. Thank you so much for enjoying what I’m doing and thank you so much for all the positive feedback I get from you all.

And as a bonus, ill leave you with some recent shots of my car just because I think it looks sick.

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