This brief article is going to explain the different components of modern automotive braking system parts including pads, rotors, calipers, drums, and more. We have written article because customers often as for “new brakes” but only seem to be talking about certain parts. Basically, this article is here to help you understand more about how the system works, and therefore are better equipped to shop for parts.
Brakes aren’t the round metal discs behind the wheel. Nor are brakes the parts that wear out and squeak.
“Brakes” refer to a set of components that work together to bring a vehicle to a stop once it is moving. Braking systems on most modern vehicles are hydraulically actuated. The brake pedal acts on a master hydraulic cylinder which, usually with the assistance of a vacuum-powered booster, pressurizes a hydraulic line and actuates cylinders at each wheel. A proportioning valve controls the bias of pressure to all four corners.
The cylinders at each wheel actuate either pistons in a caliper (for disc-brake applications) or a wheel-cylinder (on drum brakes). In disc brakes, the caliper pistons push on brake pads that have friction linings. These linings are forced against brake discs, or rotors, which turn with the vehicle’s wheel hub. This force slows the turning of the wheel and slows the vehicle.
Drum brakes work similarly with different components. Wheel cylinders push brake shoe-linings against the insides of a drum that spins with the wheel hub to slow the vehicle. Drums on modern cars are used in rear applications, if at all, and are mainly used for cost savings in low-demand applications since disc brakes are much more efficient at stopping vehicles.
Brake fluid DOT level is one of those classic cases where automotive enthusiasts fall into the “more is better” trap. Cars come with DOT3 fluid in them, as a general understanding. If I have better brakes or want better braking, DOT 4 or DOT 5 are better, for sure! Right? Maybe, but maybe not. There is more to understand here than the higher number is “better.”
Here is a Q/A article on Brake Fluid. The interview is conducted by Andrew Markel, and this was published in September 2010. The reason we are sharing this is that it discusses DOT 3, 4, and 5.1 fluids which are popular in the cars we service. Give it a read; it’s only one printed page. See our comments below the image:
So here are some comments we have in response to this writing:
Brake fluids, by-and-large, are compatible with each other. But we still prefer a homogeneous solution in our brake systems. Simple flushing is usually just fine, but if you want to be anal run some rubbing alcohol through your lines to clear them when changing fluid types.
When it says that very few drivers would feel a difference in pedal pressure with performance fluid, let’s understand that this periodical is meant for general use (all parts people selling to all drivers). Your motherÂ might not feel a bit of difference, but your spouse or you yourself may. However, a benefit might not be realized until driving quite a bit harder. So take the upgrade with a grain of salt. Not everyone will feel and change in the pedal, or like the results, if they do feel it.
We have done a few track days and aggressive roads where we have gotten the brakes VERY hot. We have yet to run into a situation where we have boiled stock Honda DOT 3 brake fluid and felt we needed something more.
There is a myth in the automotive world that tells us new rotors should be installed with new pads, and vice-versa. And that if you are not going to replace the rotors, they should be resurfaced to generate a new friction area for proper bedding.
Heeltoe says this is false, with one minor exception.
When properlyÂ beddedÂ and used over time, a thin layer of brake pad material is transferred to the brake rotor surface, and this helps create optimal friction for stopping. When a set of pads is worn out and need to be replaced, it is perfectly ok to install a new set of pads on the old rotors. The fact that a layer from the old pads has â€ścontaminatedâ€ť the surface of the rotor means little once the new pads areÂ bed in.
Bedding in the new padsÂ will wear off the old pad material and replace it with the material from the new pad. This is especially true when the pads you are installing are more aggressive than the old pads. The relatively weak material from the old pads is readily replaced with the stronger material of the new pads. Even when changing pads like-for-like, it is easy to recognize that the material on the rotor face indeed does not need to be replaced at all!
The exception to this assertion comes in when you are replacing pads with weaker ones than you have already installed. In my personal experience working with Japanese cars, I find that it is most often the case that the OEM pads really are quite weak, and nearly any grade of aftermarket pad that is installed will readily replace the material left by them. In fact, the OEM pads more often than not as so weak they have a layer built up that is uneven and causes shaking. This is often confused with the idea that the rotors might be warped. In fact, installing more aggressive pads on shaky rotors can many times FIX the shaking completely. This concept is put to work in ourÂ HT-Spec Stage 0 brake kits.
Sometimes, the rotors on the car are creating shakes that are so violent simple rebedding and pad replacement are not adequate for mitigating them. In some cases, the brake rotors may indeed be beyond hope and are needing to be resurgaced or replaced. Likewise, if you are putting on the same or milder pads than those you are taking off, the shaking won’t only persist…it will get worse. The good news is, if you are getting the shaking it is a sign that you definitely SHOULD be getting slightly more aggressive pads. That will ensure that your braking will be smoother and more consistent which will make you a much happier, more confident driver!
But, if your brake pads are going to be replaced, and the brakes cause little or no shaking in the wheel or pulsing in the pedal, a simple replacement with something a bit more HT-Spec will be all that is needed!
TheÂ 2-Piece rotor from Racingbrake, featuring a forged and CNCed aluminum hat, free-floating, center-mount design, and G3500 racing alloy material, weighs in at a paltry 12.7 lbs per side! This is a 5.1 lb saving per corner versus the stock rotor, and 10.2 lbs of the whole front axle!:
Racingbrake 2-Piece Rotor for TSX Weighs 12.7 lbs!
With the ability to stand up to street- and track- duty pads, lightweight for better acceleration and suspension action, and reasonably priced replacement rings, theÂ Racingbrake 2-Piece RotorÂ is a definite winner for street performance and track-day enthusiasts. And if you are for show, you simply cannot beat the look for the cost.
Brake rotor retaining screws are a pain to remove. They are soft, and strip easily, despite having large Phillps heads and generally not being on very tightly. Heeltoe’s got a surefire way to remove them using simple common tools that works 100% of the time. You’ll never reach for an impact driver again. And, luckily, once you get them off you don’t need to re-install them!
I hate these screws. Most European cars donâ€™t even have them, but for some reason, the Japanese feel the need to equip their cars with them. The reason they are there is to hold the rotor securely to the hub of the car once the wheel is removed. If you look at how the whole assembly of hub/studs, rotor, wheel, and lug nuts fit together, you will see that these screws serve no purpose once the wheel is installed. The screws exist merely as an unnecessary assembly aide.
Their function is so superficial, in fact, that they are made out of what must be the softest metallic substance on the entire car. Under any load from the brakes, I can imagine these screwsâ€™ heads popping off instantly. Alas, they are on the car holding the rotor in place and must be removed in order to change rotors (another insufficiently designed component of the Honda/Acura braking system, but that is another blog topic...) The process of removing these screws appears to be as simple as grabbing a Phillips head screwdriver and giving them a twist.
Unfortunately, life creates its own interesting moments when it is realized that even a very minimal amount of unseen corrosion or galvanic action LOCKS these bad boys in place, causing the screws to strip with ease. Once these guys are stripped, you need to grab a drill and bore out the heads to get them off. I have done this drilling more often than I have had the miraculous joy of actually removing the screws properly. I never want to do it again.
Letâ€™s say, I was to stop writing here. One might no doubt search their favorite message forum and read all of the wonders of a tool called an impact driver. This tool is a sort of screw-driver with a spring-loaded twisting action that works when the handle is hit with a hammer. The idea is, the hammer forces the driver into the screw while the spring action twists the screw just enough to break it free. Much of the time an impact driver is the perfect tool for the job. But I content this method is no sure-fire way to unscrew these screwy screws without possible need for the drill.
Problem one with the driver is, not everyone has one, and not everyone who changes brakes every 2-3 years wants to buy one. In order to get one that works reliably, youâ€™ll need to spend enough money that you might well have paid someone to do your brakes for you. Iâ€™ve used cheap ones and broken them almost instantly. Bonusâ€¦before they broke, they stripped the screws.
Problem two, even with a good driver there exists an estimated 10% chance you will strip a screw anyway because the screws are just that bitchy.
So here is my SUREFIRE, WORKED EVERY TIME I DID IT WITHOUT FAIL way of removing the rotor screws from your brake rotors. It involves two simple tools nearly everyone has in their toolbox.
Now it is all about technique. Make a dimple in the screw head near the outside diameter of the screw. You just need to dent the screw a little, not chop a chunk into it.
Using the dimple for â€śtraction,â€ť hold the chisel about 45 degrees from the rotor hat (make sure you put the dimple in a place not directly adjacent to a stud) and give it a few good whacks to work it free, and youâ€™ll need to rotate your position as you hit to walk the screw around.
Use a screwdriver to spin the screw out! No new tools. No special tools. Hell, you can use the crappiest hammer and screwdriver you have. The real trick is not to get too wily with your chisel because you can make mince-meat out of the screw, making the job harder and making the potential for getting that drill out a reality. With a bit of practice, you can get this process figured out before you are done changing 4 rotors.
With the screws removed, go about the business of changing rotors, and if you are re-installing the screws. Youâ€™ll have to deal with them again later though. For this reason, I usually toss them in the trash. If these are intended to make my life easier, I wonder how things would be designed if designed to work against me.
GEEK TIME! Why does this work?
It works because when driving a screw with a screwdriver or an impact driver, the majority of the twist happens very close to the center of the fastener, imparting a minimal amount of torque to the screw (remember, torque is force x distance). In order to get the amount of torque needed to remove the screws easily, force must be applied to a point on the fastener as far from the center of the fastener as possible. In T = Fd, you are increasing d.
Likewise, a screwdriver has a tendency to impart minimal grip on the screw itself, which is why when you turn it the driver wants to naturally pop out of the head as you twist. This reduces the force you are able to put into actually turning. In order to get a screwdriver that really grips screws well, you need to come out of pocket more than you might want. You will find yourself putting lots of effort into shoving the driver into the screw to prevent this action even with better tools. A quality impact driver that will handle the extreme hammering that is needed sometimes is even more costly than a good screwdriver! When using the chisel method, the force you impart on the screw is concentrated in a localized area where it does the most good without any â€śfighting.â€ť It is easy to remove the screws because so much of your effort goes into doing work, not to counter ancillary tendencies. In T = Fd, you are effectively increasing F.
There you go. All you wanted to know about getting the rotor screws out on your Honda/Acuraâ€¦and more. Too much maybe.
First, it is important to know what pads you have, and what they are capable of. Heeltoe Automotive recommends Racingbrake or Hawk Racing pads, which offer different levels of performance depending on your needs. Find out more about the differences in pads under product descriptions on Heeltoeauto.com!
Brake Pad bed-in is not a one-time thing. If you overheat the brakes or use them irregularly they can “un-bed” as it were and the friction surface is not ideal. It can manifest itself with noise, glazing, shaking….you need to go out and re-bed the brakes. Sometimes you need more aggressive pads to get it done!
This bed-in procedure is drawn from Heeltoe’s experience in breaking in pads (called bedding), and from technical information gathered from our suppliers’ websites.
All brake pads must be bedded-in with the rotor they will be used against. Even though those performance street pads have been burnished at the factory, a transfer film must be generated at the pad and rotor interface for optimal performance. Whether it is new or used rotors, you must follow the bed-in steps listed below to maximize brake performance.
STREET PADS, example Racingbrake ET300/500, Hawk HPS, Ceramic, and HP+
After installing new brake pads, confirm pedal pressure before driving the car. On an open road with no traffic, make 3-4 heavy slow-downs, NOT complete stops, from 30-10 mph then fast acceleration and repeat with increasing pedal effort/brake effort each time until just shy of ABS activation. The idea is to heat and maintain that heat in the pads and rotors during the procedure.
On an open road with no traffic, make an additional 2 to 3 hard slows from approximately 45 mph to 5 mph applying firm pressure. Do not drag brakes or come to a complete stop. Engagement of ABS or threshold braking is not required but if it happens that is ok.
Now, gradually building heat into the brakes, I like to run up to about 80 and bring the car down to about 40 mph in a short distance with heavy pedal pressure. Do this 2-3 times. You may experience some fading if your brake fluid is not upgraded and you have stock brake lines.
Allow 15 minutes for the brake system to cool down by cruising at normal speeds.
Do not sand or grind the brake pads or rotors after this burnishing procedure has been completed. Your performance street pads are now ready for driving! I generally recommend driving the car normally from here on out. I do not recommend using the brakes as a way to slow the car down, but rather use them as a way to CHANGE SPEEDS to a lower one. Keeping this thought in mind while braking will prevent you from making long gradual stops that raise brake temperatures above the desired level for street pads. When street pads get too hot, they can glaze the rotor surface or put inconsistent pads deposits on the rotor which will cause a shimmy.
Also, be aware that Racingbrake rotors have special metallurgy that may require up to 500 street miles before break-in is achieved. You will need to get these rotors HOT! If there are not plumes of smoke billowing from new Racingbrakes you probably did not get them hot enough.
Lastly, do your best not to engage the ABS system within at least 300-500 miles of bed-in. If a shimmy should develop, one should reapply the bed-in procedure listed above.
You will know your brakes are bedded correctly when they look smooth without much or any trace of the factory’s cross-hatched finish.
These Racingbrake 2-Piece rotors were returned to us because the customer was having a shimmy problem. We saw as soon as we opened the package we noticed that they had not been bedded properly. Even with ET500 pads, the bedding was not aggressive enough to take down the cross-hatching.
The same rotors as above after being bedded properly. I took the returned rotors and put them on the HT-Spec TSX. Some initial shimmy was noticed until the heat was built up and pedal pressure increased. All shaking prompt went away ad has not returned in months of mixed driving. It is not the greatest image, but you can see the cross-hatching is gone after one bedding session.
If you hear a noise after bedding that sounds like the brakes are dragging a little, this is relatively common. As your brakes wear in this noise will go away or at least will get very faint.
If you are looking at the not-bedded image above and notice that dimple in the rotor face, it is also normal. This dimple is evidence that the rotors have been hardness tested to ensure quality control. The dimple is deep an will not go away, and it does not hurt anything. If anything, be glad it is there since no other brake companies really seem to care enough about their products to test their hardness before shipping them!
RACE PADS, example Hawk Blue or other Motorsports Pad
Prospective racers are cautioned that unless these racing pads are properly bedded-in at race track conditions it can result in premature failure or ill effect.
Seal all brake ducts if any.
Slowly engage brakes 6 to 8 times at medium speeds (60 – 80 mph). Do not drag brakes or come to a complete stop.
Increase speeds to simulate race conditions; allow 6 to 8 high pressure (about 500 psi) snubs at racing speed. Total engagements for Step 2 should be a maximum of 15 to 20.
Remove brake duct seals. Allow the system to cool for about 15 minutes. Do not engage brakes while the car is parked during the cool-down period.
Do not sand or grind the brake pads or rotors after this burnishing procedure has been completed. Your motorsports pads are now ready to race!