sonicx

Thanks... I believe im set.

99BlackPonyGT

heres a compilation of things about brakes

How brakes work (yes, this info has been copied from many other places, why well you dont have to search for answers, you can find them right here on your own forum)
Of all the systems that make up your car, the brake system might just be the most important. In the olden days it was also one of the simplest. Over the years as improvements have been made, the system that has evolved isn't so simple anymore... (It's also about a zillion times more reliable and safer.)
Your brakes work as hard or harder than any other part of the car, however much energy it takes to get your car up a hill, it takes at least as much energy to stop it at the bottom. Think about that for a second. Here, I'll say it again, it takes at least as much energy to get your car safely down a hill and stop it at the bottom, as it took to get your car up the hill in the first place. Your brakes do this by converting the kinetic energy to heat energy. All of this heat is generated between the friction surfaces of your brake pads and your rotors. (I am going to disregard the rear brakes for now, since the front brakes do the lion's share of the work.)
Rather than try to give you a step-by-step procedure for repairing your brakes, I'm going to try to show you how to diagnose a few of the many simple brake problems. Unfortunately, before I can do that, I have to talk about how the brake system works. If you already know how it works, then you probably already know what your problem is, but you might find something useful here anyway, or at least I hope so.

Brakes operate on a simple hydraulic principle. (See diagram below) If a force is exerted on the piston putting pressure on the fluid confined in the left hand container, the fluid is forced out through the narrow tube at the bottom and into the right hand container, exerting a force on the second piston, forcing it to move upward.

Now this is how the force from your foot gets to the four corners of the car. If we add a lever to magnify the force applied to the first (master) cylinder, and maybe even a power booster unit to increase that force even more, all we have to do next is figure a way to use that force to slow down the wheels. Since the wheels are attached to the car, slowing them down will slow the car.
If we change the shape of the right hand container, (see below) to make something for the piston to push against, we can make it pinch something. Let's bolt a disc(Brake rotor) to the wheel, so that it rotates whenever the wheel does. We'll mount it in such a way that the edge of it is between the caliper piston and the caliper that we have bolted to the axle of the car. So that when the piston moves out, the disc is pinched between it and the other side of the caliper. Actually we're not quite done. As we have the system now, the disc and the caliper would wear out rather quickly (not to mention making horrible grinding/scraping noises). We need to put something between them to protect the surfaces. Let's call this part "Brake Pads" But wait, as we have drawn it, the piston only pushes on one side of the disc. We have to allow the caliper to slide back and forth if we want it to actually pinch the disc efficiently. Let's make an anchor post and allow the caliper to slide along it. Let's make a nice, strong mount to hold the brake pads, and secure it to the axle. Now all we have to do is mount the caliper assembly to some sturdy part of the car and we're in business.

Brake pads have two main parts, the steel backing, and the actual friction material. The backing is only there to support the friction material, which does the actual work of stopping the car. The friction material does it's job by converting the energy of motion to heat energy. This is done by the magic of friction. The friction between the pad and the disc slows down the disc, and creates heat. This heat is transferred to the pad and the disc and then (at some fixed rate) dissipated to the surrounding air. How fast that heat is radiated is determined by a simple formula, depends on mainly two factors, the temperature of the air around the parts, and the flow of air past them. 99% of the time, this cooling is more than enough to keep the brakes cool enough to work just fine.
OK, I dont think this is covered in my basic trouble shooting sticky, now we have our simple brake system. Let's see what can go wrong...

Air in the system
This is usually caused by air getting into the brake fluid area, usually from the master cylinder. As the brake pads wear, the caliper pistons ride farther out of the caliper, allowing more fluid to remain in the calipers. Over time this can add up to almost as much fluid as there is in the master cylinder reservoir. If neglected, this will allow the master cylinder to pump some air into the brake lines. Air is very compressable, whereas brake fluid is not, as long as there is a solid stream of brake fluid between the master cylinder piston and the caliper piston, the brake pedal will be nice and firm. If there is air in the system, the pedal will feel spongy and will go down almost all the way to the floor, maybe all the way, depending on how much air is in the system. The standard way of dealing with air in the brake system is to perform an operation called "bleeding the brakes".

Hard brake pedal
Can be caused by bad power booster, (or loss of vacuum to the booster) seized caliper pistons, seized caliper slides, pinched brake lines, and (rarely) problems with the pedal linkage under the dash. The probable best fix is rebuilt calipers,and new pads.

Brake squeal
This is a high pitched squealing noise, often heard when you are going slow and are not applying the brakes. If it goes away as you apply the brakes, it could be coming from the brake wear sensors. (Also called 'squealers' by mechanics.) They are small bits of spring steel that are attached to the brake pads in such a way that when the pads are about 75% worn out, the sensors start to rub on the rotors, making the noise. GM invented them, and they are one of the best ideas anyone has ever had in the automotive industry.(yes i said some thing nice about gm) The sound is so scary that you usually go to a mechanic before any major damage is done to your rotors, and before your braking power is compromised, saving you money and maybe your life.

Brake fade
I have seen too much of this, having spent 5 years at the bottom of a 13 km hill with 15% grade and continuous switchbacks. Two phenomena contribute to brake fade, one is the fact that the coefficient of friction of most substances gets lower at high temperatures, and that most liquids will boil at some temperature, and that gases compress, while liquids do not. When you use the brakes to decelerate 3,000 or 4,000 or 7-8-15,000 lbs of vehicle, they get hot. Very hot. Under normal circumstances this would be no big deal, the heat that builts up in the pads, rotors, and calipers will slowly radiate back to the air flowing over them as the car continues down the road. But you aren't going down the road, you are back on the brakes, doing more decelerating for the next switchback. Instead of cooling off, your brakes are getting hotter. And hotter, and hotter. . .As the pads and rotors get hotter the friction material of the pads starts to separate. The binding agent starts to boil off from the surface of the pad, plating out on the rotor as a dark, paintlike film...coefficient of friction approaches zero, pedal gets hard, but no braking action. Your pupils dilate to 10 mm and your body goes into fight-or-flight mode, adrenalin courses through your system. But the car just goes faster.... You shift down, now you are standing on the brake pedal with both feet, around this time, the temperature of the brake fluid in the calipers usually reaches it's boiling point and the pedal just sinks to the floor. Your pupils reach 12 mm, your sphyncters contract to pinpoints, somehow you manage to stop the car. There is smoke coming from behind your front wheels, maybe fire. You put out the fire and have lunch. After things cool off you sit in the car and try the brake pedal, it feels almost normal. Congratulations, you've just experienced, (and survived) brake fade. (You've also just flash-fried your front brakes, figure on new everything to fix it properly.)

Grinding noise
Although this is one of the nastiest sounds you will ever hear, it often is the easiest to repair. The first thing you must do is learn what is making the noise. Figure out which wheel it is, then, after safely raising and supporting the car, take off the wheel & tire. Hopefully you will see a simple disc brake system, with a rotor, a caliper, and brake pads. Identify the various components. Gently rotate the brake rotor back and forth until you can identify the source of the noise. Sometimes it is just a small stone, trapped between the brake rotor and the air deflector. The faces of the rotor should be smooth and clean. If you see large scaly rusted places on the friction surfaces of the rotor you should replace them. Most of the time new ones cost less than you would guess. If your pads are worn out(less than 3/16 of an inch of friction material left) and you catch it in time, all you have to do is install new brake pads. If the surface of the rotor is damaged, you will have to resurface or replace it.

Brake pedal pulsation
There are a lot of things that can cause this, from out-of-adjustment wheel bearings to rotors that are bent, brake drums that are out-of-round, rusty spots on the rotors that have a different surface smoothness. To determine whether the pulsation is coming from the front or the rear wheels, check to see if you can feel the pulsation in the steering wheel when the pedal is pulsating. If you can, the problem is coming from the front wheels.

Brake pull
Mostly this one comes from either a caliper piston seized or caliper slides seized. This one is dangerous! If your car tries to turn when you apply the brakes you could veer into oncoming traffic. What often happens with this one is this: the caliper piston on one side starts to seize, the other one now applies first, car veers away from bad part. Driver learns to compensate by steering opposite to the pull every time he brakes. A panic situation comes along, driver nails the brakes, steers away from the expected pull, but because the piston was only partially seized, it works just fine when the brakes are applied with vigor. There is no pull this time. It is easy to lose control of your car in situations like this, if your car pulls to one side or the other when you brake, fix it(or get it fixed) before you hurt somebody. Replace calipers and pads and service the caliper slides. This can also be caused by bad caliper hose's, they may look fine on the inside, but internally, they colud be damaged.

Brake grabbing
When you just barely touch the brake pedal and one or more wheels locks up and skids. This one most commonly comes from contaminated friction material on one or more brakes. Mostly seen in drum brakes when the wheel cylinder is leaking or axle seal is leaking!

Pedal goes to the floor
Gotta be the scariest of them all. If you're lucky, a quick pump on the pedal will get you some braking action. On most newer cars, there will be some braking just before the pedal reaches the floor. Stop driving and check your fluid level. It might just need to be topped up to temporarily get you some braking action to get you home. Regardless, you must find out what caused it and fix it before you drive any further.

what all parts are in a braking system
Components
Disc brakes have:
brake calipers
brake pads
rotors
caliper mounting hardware

Drum brakes have:
brake backing plates
brake drums
brake shoe self-adjusters
brake shoes
brake springs
wheel cylinders

Both types use:
Brake fluid
Steel brake lines and reinforced rubber brake hoses
Master cylinder
Power brake booster (usually)
proportioning valve
delay valve
metering valve
brake warning light
park brake cables, levers,

99BlackPonyGT

Cross Drilled VS Slotted Rotors
by mike_sho

Over the years ive heard many debates on the actual benefits of modified or aftermarket brake discs. Many times it seems most people are confused of the better. Where in most cases its not a straight cut answer when it comes to tuning and choosing the right application for the job. Two of the most common types of ventilation on brake rotors are Cross Drilling and Slotting

Which one is better? In the next section we will go over simple benefits and drawbacks of each system. To answer the question beforehand , there isnt one standard answer for all cars and environments. As well as driver. A track based car will be setup for its environment to best suit the situation at hand. One might benefit from a certain setup where as a street car with the same setup might see adverse effects.


Slotted Rotor Attributes:

- The slots on the rotor helps clean the brake pad, which improves bite.
- The slots on the rotor will slice the brake pad allowing the pad to bite harder into the disc causing an increase in disc temperatures. This will bring your brakes up to temperature faster , but might also take you too far decreasing the benefit. The slotted rotor coupled with a race pad which need to be heated would be optimum.
- Slotted rotors will also cause slightly more brake pad wear and tear giving you less miles on a pad before it needs to be replaced. Shorter maintenance schedule.
- Slotted rotors allow gas to ventilate during brake fade.
- Slotted rotors are less prone to cracking then the cross drilled rotor.
- Slotted rotors weigh more.
- Slotted rotors have more disc surface.
- Slotted rotors maintain around 96% of the friction surface

Drilled Rotor Attributes:

- Drilled Rotors offer an enhanced initial bite.
- Drilled Rotors perform better in wet weather over the slotted rotor. Due to volume of a hole vs a slot.
- Drilled Rotors are more prone to cracking than slotted.
- Drilled Rotors allow gas to ventilate during brake fade.
- Drilled Rotors offer a performance benefit since there lighter in weight.
- Drilled Rotors have more ventilation so they should cool off faster , but have less rotor material so they could get hotter than a slotted rotor. But its hard to say as the slotting also increases heat.
- Drilled rotors maintain around 85-93% of the friction surface


Drilled and Slotted Attributes:

- The slotting will increase rotor heat.
- The drilled holes will increase the cooling after braking.
- The drilled holes will increase the water braking.
- Drilled and slotted are the least reliable.
- Drilled and slotted are going to weigh less from the same manufacturer. Other designs might be lighter from company to company.
- Drilled and slotted will give the most performance benefit to acceleration due to the lighter weight.
- Drilled and slotted will also be the hardest on your brake pad (wear and tear)
- Drilled and slotted only maintain 80-91% of the friction surface.

Overview & Suggestions:

If you can stand the increased pad wear. Slotted is pretty much a great choice for stopping power and reliable both on the street and track. Good for auto-x / road course and mountain downhill racing.

Allthough if your looking for an acceleration increase as well. A drilled rotor might be the best choice. As well works well in water/rain. All good for the street or drag racing.

The Slotted and Drilled rotor could also be a good combo for someone whos into racing or ok with increased pad wear. But youll notice that it also provides the least amount of braking surface as well the least material on the rotor. Which some attribute more brake rotor material to being able to withstand heat better. Just imagine a block of metal being heated by a lighter vs a thin strip of aluminum from an intake. The thinner and or smaller amount will allow quicker and higher heating. Which will increase rotor temps which might take your brake pad out of heat range. So its a toss up on this one.

Another factor to remember is the frequency of slots or drilled holes on the rotor itself. How far they are spaced or how frequent they come. I believe a good slotted and drilled rotor combo would be that of one that has a few sets less on the holes , replaced by a small amount of slots. 3 or so. This will give more of a sharing effect rather than an overly done rotor.

Then there are the "big brake" kits. Which cost an arm and a leg, use oversized rotors and larger calipers with sometimes more pistons in use. These are indeed great braking systems. But we find this is complete and total overkill. Not only does it decimate your wallet and car budget, which isnt even the point. Maintenance is also exspensive (if the time does come), brakes are wear and tear item and sooner or later they will need replacement. As well there going to give you a big hit on performance in acceleration and unsprung weight. This is why we say stay away from these kits. With some smart choices you can have all the braking power youll ever need with the stock oem braking setup. Some aftermarket rotors and brake pads will give almost any car the ability to lock your tires. Which in the end result is what your aiming for. The ability to stop the tires from rotating from whatever speed you achieve, to a complete stop. Without much fade. As stated above its just too much of an overkill to fit a car with a large brake kit. Unless your car is running 8's and your almost hitting the wall at the end of the 1/4 mile. Then for safety reasons you might want to go this route. Otherwise your tires are what connect you to the road and those are your main bottleneck. If you want to stop faster. Tires are where that kinda money should be spent.

Now onto when shopping for a rotor , look at a few companies. Check out all your options and the different versions from each company , ask about how many holes or slots there are and dont just believe what image your being shown online is really whats in your box. Have them look at it. Also when they offer the slotted and drilled , take a look at the design. Did they decrease some drilled holes to make room for the slots or did they simply slap in some slots in between the drilled holes. This makes a difference and if you use the above guide you can also figure out the performance change and the benefit you might have as the end result driver and user. What risks your willing to take on reliability and maintinenace and where you want to see performance increases.

Another thing to remember is to find out who does the drilling and slotting for the rotors your purchasing. A lot of these places online and ebay will do in house drilling and slotting. Dont feel bad to probe these people and see how they are doing it. Some use outside manufacturers who will most likely have a better system at doing it. Some in house people might modify your holes by hand...which might end up a disaster. Be sure to get chamfered holes , this makes them smoother , more durable and less harsh on the brake pad. Beware of the ebay stores and brembo rotors. Brembo sells oem blanks to almost anyone and they are the ones doing the modifying. Usually these are not the best choice , especially drilled because they were meant to be pretty much stock replacements. There is the brembo sport rotors which brembo does themselves and is much more durable. So find out how they did it or what there seling before investing your money in your braking system and essentially your life.

The best bet is to get a good street performance pad. Some good brake fluid for starters. If this isnt enough or you still get fade , get some rotors. Then if you want better pedal effort get ss lines.

If your going to go with low cost rotors that are slotted or brembo slotted. It would probably be best to stick with slotted. Otherwise look for performance models.


Otherwise like stated if you like solid rotors , thats all you , but this article is about slotted vs drilled. And drilling oem rotors is where you get cracks , but pre-made drilled rotors like from brembo probably will not and or would be under warranty so either way your covered. As well were not nascar , were not worrying about finishing a race and were not pushing earthly metals to the limits of heat and durability. Were worried about bumping up our street drive or track drive. Auto-x is also not so hard on a cars brakes...it takes a good bit of very tight driving on an auto-x course to really get them up to heat. Either way even at the auto-x youll benenfit from a vented pad due to the initial bite.

If anything downhill mountain racing would be the most vicious on


If anything for those that love solid discs. You should try a slotted. For those that dont want a cracked rotor , then yes stay away from a drilled rotor. Thats why Ive noted all the points for each and let one decide the other. To say one is better than the other is pointless.

But if you want to never have a cracked rotor. Then yes , slotted is the way to go. Otherwise the pluses and minuses have been listed for those to pick and decide whats best for them. Iam just noting the differences.

Like drilled will be lighter (sorry but they will).

And all slotted rotors clean the pad so its got better bite and less fade during venting.

That simple. Comparing the cheaper blanks/solids. Does nothing , yeah they cost less and if you do your own labor its cheaper. Great , but they do get outperformed by a slotted and even the drilled rotor. Your going to risk cracks etc with the drilled. Thats the only drawback.

Ok I'm getting a lot of braking questions, and people are STILL blowing money on ****ty rotors, so I will tell you all why blank rotors are better.

The reason for the creation of cross drilled rotors initially was to remove the "gasses" from the brake pads. HOWEVER, most of your modern brake pads (Axxis metal, AEM semi-ceramic) do NOT produce gasses when heating. This was on bad brake pads used in the 1950s and 1960s. Back then, asbestos was also used, and we dont use that either.

The other reason is so called heat dissapation. I don't have my physics and thermo books with me, but the logic is that the holes in the rotor are suppose to allow the brake pad to cool. So...air gets into the rotor from the inside of the vents. If you have a back rotor which is solid, air gets into these holes how? If your stopped, you are leaving air inside these holes sandwiched between the pads, thus creating air with a rising temperature. Its increasing in pressure from the heat, which I guess you "could" call a gas that would affect braking. So the cross drilled rotors do not remove any gasses formed by brake pads (because there are none created anymore) but could possibly inhibit the creation of "hot spots".

Cross drilled rotors have LESS contact area because of the holes.
But if the rotor is cooler, its better, right? Well no, because these rotors are not cooler. the heat is generated from the pad/rotor contact. What removes heat the most effectively? When stopped or moving, the pad transfers heat into the rotor because its made of cast iron. the rotor has a lot of surface area and even vanes in it. But the little holes allow air in this surface contact, and you can transfer more heat into a solid big *** chunk of cast iron more than you can into the air. Don't believe me? Touch some steam at 150 degrees, then touch a piece of hot metal which is at 150 degrees. Which burns your hand? the metal. So let the heat transfer into the metal, because since it has so much more surface area, dissapates better.

Safety!!
Cross drilled rotors can crack! I have seen them!!
this is a pic of a crappy slotted rotor for reference

why might you ask? well when i was at north western,we had a Guest speaker from brembo give us a 2 hour long seminar on brake technology and he mentioned something very important about slotted rotors. when purchasing a slotted rotor make sure the manufacturer has cut the slot into the rotor without Going all the way to the edge of the rotor. it's hard to explain so look at the pic above of a poor manufacturing process.

now the slots should Never exceed to the edge of the rotor. the reason for this is in a circle the outer edge plays a significant roll in the ingerity of the entire unit. it's just when you cut into that circumfrance edge you drasically take away the strength of the rotor. this can lead into a very bad crack or shatter. think of a piece of glass, the way you cut it is to score it with a cutter. however, the score is only usefull in breaking the glass if you run the score all the way edge to edge.
this is a pic of a quality slotted rotor


f1 and nascar are certain track based events with totally different power and there taking again what metals we have to use to limits far beyond a street car. Therefore they probably cant run slotted etc etc, because there already at the limit of a rotor. Slotting again does two things , cleans the pad and allows more bite into the pad. Imagine your hand on the disc of a solid as its spinning , then a slotted. Youll grab the slotted disc easier. The other benefit is if the brake pads start venting and they will in hard street use. Then the slotted rotor will allow the gas to safely expell without effecting the space of the pad to the rotor.

Even racing teams will recommend AGAINST cross drilled rotors:
http://www.livermoreperformanc....html


Companies that sell cross drilled rotors that are redrilled may not be structurally sound. I have actually seen pictures of rear Integra rotors that have had hairline cracks turn into the rotor actually breaking apart!

Do your homework. Even Porsche and Ferrari will admit that the cross drilled rotors they use are for looks. So if you are one of those kids who thinks the little holes look cool, get a name brand drilled rotor like Ferrari does. The REASON Ferrari's 'holed' rotors are alright to use is because they are CAST with the holes in them, so they are not actually drilled into cast iron rotors. Cheap drilled rotors are not safe, and even the good ones are not necessary. Why do Ferrari do it? People THINK they want it, and it sells. If you don't believe me, go into the business world. You will learn that pretty soon, you can sell utter **** if people THINK its better.

99BlackPonyGT

Why should you upgrade to cross drilled rotors?

Simply stated, the function of any vehicles brake system is to stop the vehicle. This is accomplished by absorbing the kinetic energy stored in the moving vehicle, and converting it into heat. The friction caused by the brake pad rubbing on the rotor is the source of this heat. The more quickly and efficiently that heat can be absorbed and dissipated, the more quickly and efficiently the car will stop.

There are several contributing factors to this heat reduction. One of the most common sources of heat is from the gases produced by the bonding agents of the brake pad burning off. Under severe braking, this can actually produce a boundary layer of gas that pushes the pad away from the rotor, which can lead to excessive brake fade. The cross-drilled holes or slots in a rotor provide an escape path for these gasses (de-gassing or out-gassing are common terms), and allow the pad to stay in contact with the rotor. As well as de-gassing, cross drilling or slotting will provide better wet weather braking as water is swept through the holes, or down the slots.

A vented rotor can be viewed as an air fan. When in motion, the vents draw air from the center of the rotor outward. This air flow, over an increased internal surface area, effectively dissipates rotor heat. Cross drilling adds to this air flow, as well as providing additional rotor surface cooling. "

This company is just telling you that the rotors may be cooler, however they fail to mention that the holes really do create a more than substantial decrease in surface area, thus less braking, thus less heat created, thus the less heat CREATED will leave the rotors cooler, the holes barely do anything! Its the less braking lowering the temperature!

Slotted rotors-
Find me a company that uses stock slotted rotors. They remove brake dust, but if you study braking systems, you find that with modern cars, flat blank rotors and semi-ceramic pads, the brake dust causing the rotor to slip on it is almost non-existent. But the brake dust doesnt need all those lines. Notice how most front brake pads (and most back) have that line down the middle to give essentially two bite points. If OEM or racing companies found it to be a benefit, they would do it.

PROOF OF IT ALL:

Find me an F1 car as of now that uses cross drilled or slotted rotors.
They all use full ceramic rotors and ceramic pads. Are they drilled or slotted? No.

If they helped the fastest cars in the world, wouldn't they use them? Its basic calculations that show the lack in surface area does not make up for the possible loss in temperarure. They use brake cooling air ducts insted.

BIG BRAKE KITS:
Some have asked if the big brake kits are worth it. This is sort of a relative question, but the simple answer is no. Regarding the big ones with drilled rotors, if you know that they are cast that way, at least they wont crack. I will still advice against them.
In terms of a big brake kit, I have seen some for Civic DX models. Civics have the small pad, small caliper, and a 9.5" rotor. The big rotors are 12" in diameter, ok so the overall diameter is close to that of an Acura RL (1999). But the sweeping area (the area that the pad can grab) is still the same if they use the same caliper and same pad. If you have the same pad and caliper, you are using the same rotor surface, just farther out, so it will increase braking from stock. However, if you were to change knuckles, etc, and get Acura RL caliper (larger piston than your civic DX piston), RL pads (much bigger and taller), and RL rotors 11.8" but much more surface area is touched, then you have a better brake setup because you have OEM parts, and a better grip on more area of the rotor. The downfall is added weight (since big brake kits are usually 2 piece and lighter) but the benefit is that you have so much more stopping. Ok, so the big brake kit will have less unsprung and rotational mass (so a little better accelleration but less braking), but they tend to run over a grand, and you can use OEM parts to build a better setup for half that.

IN CONCLUSION
Don't buy slotted or cross drilled rotors, blank are better, and stop better. Physics people, get me my formulas and help me out here.


Pad and Rotor Break In
Called burnishing I think. They said the mechanics are supposed to acutally use a thermo device at the shop the heat up the brakes to exact specs in the SAE manual and keep it there for so long. The other method is a 30-30-30. 30 MPH hit the brakes firmly not hard come to a stop are start going again wait 30 seconds and do it again. Do this 30 times and it should be done. So I would definately recomend doing this on new brakes.

!!I have found the posting limit is set to 15000. I was over 30k
and i have not even touched pad's yet...i will get to that later. if this is sticky worty, then do so.(been working on this for a while now, cause going thru tons of braking info, and adding some of my stuff from class's and web write ups and so on)

99BlackPonyGT

i did not write any of that, its all copy paste...not trying to take credit for someone else's stuff