When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Here is a message I sent to Hawks regarding my bad experience with the HPS pads.
I contacted you guys before but I never got a reply. I purchased Hawk HPS brake pads for my 2009 Mazda RX-8 from racingbeat. Installed the pads and broke them in following the instruction. The pads are completely inadequate to use with the rotors as they are not hard enough to cut into factory rotors to provide adequate friction. Stopping is very dangerous on these pads even after 1000 miles of driving and two mild track days. The rotors never got worn and had dark tarnish due to material deposit.
I took them out and put old factory pads back in, braking resumed great right away and the rotors turned into shiny again.
Several days ago, I was putting new factory pads back in and noticed part of the dust boots on the piston missing in a very weird way. Mind you the car only has 27000 miles and never driven in snow. The factory pads have rubber shims and SS covers which cover the whole surface of the pads.The rubber shims on the piston side also has cuts in them to allow air flow to cool the pistons. The Hawk HPS pads comes with shims that do not cove whole back of the pads not do they have enough cooling. As a result, part of the dust boots were touching the actual metal base of the pads. In addition to that, the pads were never hard enough to provide adequate braking so they were constantly overheating causing the rubber to burn off.
I hope this comes to your attention that as a reputable company, Hawk should stand behind their products instead of ignoring the problems.
Here is a photo of my calipers. I now need to rebuild them at least.
Updated photos for those who want to see more details about this issue
Pads comparison. Hawk on the left and OEM on the right. I see no glazing.
Pad material difference. OEM is much more darker and rougher.
Driver side piston seal. Same deal.
Shim coverage. OEM slightly bigger.
Shim thickness. OEM much thicker. Also OEM pad metal backing is tapered around the edges to avoid contact with the rubber dust seal where Hawks are much more 90 degree.
Last edited by jasonrxeight; 06-08-2015 at 08:39 PM.
The pads are completely inadequate to use with the rotors as they are not hard enough to cut into factory rotors to provide adequate friction. Stopping is very dangerous on these pads even after 1000 miles of driving and two mild track days. The rotors never got worn and had dark tarnish due to material deposit.
HPS pads are street pads. They are not meant for track use at all and will not perform well there. They are supposed to be one notch above most OEM pads in terms of stopping power, but on cars with good factory brakes like the 8, a driver may see little to no benefit over stock.
Brake pads do not "cut into" rotors. Modern street pads are very gentle to rotors. They continuously lay down a friction material on the rotors, which is then used against the pad material to stop the car. The discoloration you were seeing was incompatible friction materials in conflict with each other from the two different pad compounds used on the same rotors. If you had burnished or turned the rotors before installing the new pads, the "tarnish" would not look the way it did, and the pads probably would have performed better. Another aspect you need to consider is that the OEM pads and rotors mated themselves together over a period of 26K miles. When you put new pads on old rotors without turning them, the new pads only contact the rotors at the high spots, which means in a few rings around each rotor, until the new parts have time to mate together over a period of... thousands of miles. In that scenario, very little surface area is available to contribute to stopping power.
I took them out and put old factory pads back in, braking resumed great right away and the rotors turned into shiny again.
Several days ago, I was putting new factory pads back in and noticed part of the dust boots on the piston missing in a very weird way. Mind you the car only has 27000 miles and never driven in snow. The factory pads have rubber shims and SS covers which cover the whole surface of the pads.The rubber shims on the piston side also has cuts in them to allow air flow to cool the pistons. The Hawk HPS pads comes with shims that do not cove whole back of the pads not do they have enough cooling. As a result, part of the dust boots were touching the actual metal base of the pads. In addition to that, the pads were never hard enough to provide adequate braking so they were constantly overheating causing the rubber to burn off.
The cuts in the shim are not there to provide air flow for cooling. They are there to provide air flow for evaporation.
I know of two ways Hawk pads can damage the rubber boot. One is close to as you suspect, but with a twist. If you take HPS pads to the track, they will not have enough torque to provide adequate stopping power, and you will find yourself standing on them. You will be on them longer and harder than you would with more appropriate brake pads. That will certainly overheat them. The second way is somewhat related to the first. At least some Hawk pads (I have not looked at the thickness numbers for all of them) are thicker than OEM. When installed, the dust boot can contact the pad. That is fine if you do not overheat the brakes, but not so fine if you do. Having the rotors turned usually solves this by creating a little clearance.
When was the last time you bled your brake fluid? If you are running DOT3 fluid, you need to bleed your brakes after every track day. If you are not doing that, boiled fluid could be compounding your issues.
Many people really like HPS pads. In my opinion, your troubles with the pads stem more from expecting them to be something they are not exacerbated by improper installation rather than a true failure of the product. Had you turned the rotors and installed HP+, you would probably be a happy camper right now (excepting the noise). Or, turn the rotors and try them again. Or, just stick with OEM. I have tracked OEM pads a few times and found them to work well enough for a casual day and to be better than a lot of aftermarket pads.
Last edited by Steve Dallas; 05-16-2015 at 06:49 PM.
HPS pads are street pads. They are not meant for track use at all and will not perform well there. They are supposed to be one notch above most OEM pads in terms of stopping power, but on cars with good factory brakes like the 8, a driver may see little to no benefit over stock.
Brake pads do not "cut into" rotors. Modern street pads are very gentle to rotors. They continuously lay down a friction material on the rotors, which is then used against the pad material to stop the car. The discoloration you were seeing was incompatible friction materials in conflict with each other from the two different pad compounds used on the same rotors. If you had burnished or turned the rotors before installing the new pads, the "tarnish" would not look the way it did, and the pads probably would have performed better. Another aspect you need to consider is that the OEM pads and rotors mated themselves together over a period of 26K miles. When you put new pads on old rotors without turning them, the new pads only contact the rotors at the high spots, which means in a few rings around each rotor, until the new parts have time to mate together over a period of... thousands of miles. In that scenario, very little surface area is available to contribute to stopping power.
The cuts in the shim are not there to provide air flow for cooling. They are there to provide air flow for evaporation.
I know of two ways Hawk pads can damage the rubber boot. One is close to as you suspect, but with a twist. If you take HPS pads to the track, they will not have enough torque to provide adequate stopping power, and you will find yourself standing on them. You will be on them longer and harder than you would with more appropriate brake pads. That will certainly overheat them. The second way is somewhat related to the first. At least some Hawk pads (I have not looked at the thickness numbers for all of them) are thicker than OEM. When installed, the dust boot can contact the pad. That is fine if you do not overheat the brakes, but not so fine if you do. Having the rotors turned usually solves this by creating a little clearance.
When was the last time you bled your brake fluid? If you are running DOT3 fluid, you need to bleed your brakes after every track day. If you are not doing that, boiled fluid could be compounding your issues.
Many people really like HPS pads. In my opinion, your troubles with the pads stem more from expecting them to be something they are not exacerbated by improper installation rather than a true failure of the product. Had you turned the rotors and installed HP+, you would probably be a happy camper right now (excepting the noise). Or, turn the rotors and try them again. Or, just stick with OEM. I have tracked OEM pads a few times and found them to work well enough for a casual day and to be better than a lot of aftermarket pads.
If you say they are compatible OEM pads, they are NOT! NOT EVEN CLOSE. When I had the OEM pads, I can do laps after laps on this 2 mile track not feeling brake fade at all. With these pads, they will fade on just second lap.
Yes, I turned the rotor. Pads DO cut into rotors. I turned the rotors and installed the Hawks. The surface didn't even change a bit after 1000 miles and two days on the track. It left tarnish on the turned rotor. The moment I threw on the factory pads, the rotor start to turn shinny exposing new metal. Also the texture that rotor turning machine left completely disappeared after just 500 miles of normal driving. If you say pads don't cut into rotors, how is the texture gone and rotor turning smooth again?
I am gonna stick with factory pads. They work very well with the rotors.
Maybe you got a defective set, but a huge number of HPS owners will disagree with you about their performance in relation to OEM for street use. I have never tried HPS, so I can't speak from direct experience. I do have quite a few friends who use them on different cars on the street and for the occasional autoX and love them. But, as I said, the 8's OEM pads are very good, so that may be the difference.
Since we are talking about street pads here, I am making generalizations about street pads only. And, street pads are generally very easy on rotors. There will always be some wear since two things are grinding against each other, but it takes a long time with most street pads to see any visible wear. When you are stopped in traffic, take a moment to glance over at the rotors on the car next to you. Most late model cars have beautiful, perfectly smooth rotors.
By design, street pads are made to be low noise, low dust, and low wear items. According to your description, it sounds like OEM 8 pads use a more aggressive compound than most others, which is why you are seeing some wear faster than you normally would. That would makes sense considering how well they perform. I honestly do not remember what my rotors looked like before I had them turned.
When I think of "cutting into" rotors, I think of what my track pads do to them, which is quite dramatic.
Maybe you got a defective set, but a huge number of HPS owners will disagree with you about their performance in relation to OEM for street use. I have never tried HPS, so I can't speak from direct experience. I do have quite a few friends who use them on different cars on the street and for the occasional autoX and love them. But, as I said, the 8's OEM pads are very good, so that may be the difference.
Since we are talking about street pads here, I am making generalizations about street pads only. And, street pads are generally very easy on rotors. There will always be some wear since two things are grinding against each other, but it takes a long time with most street pads to see any visible wear. When you are stopped in traffic, take a moment to glance over at the rotors on the car next to you. Most late model cars have beautiful, perfectly smooth rotors.
By design, street pads are made to be low noise, low dust, and low wear items. According to your description, it sounds like OEM 8 pads use a more aggressive compound than most others, which is why you are seeing some wear faster than you normally would. That would makes sense considering how well they perform. I honestly do not remember what my rotors looked like before I had them turned.
When I think of "cutting into" rotors, I think of what my track pads do to them, which is quite dramatic.
OEM pads feel metallic to me.
They squeal a little under light braking but like I said they work very well stoping from 100+mph repeatedly. I was more worried about the engine getting cooked than the brakes.
Regardless Hawks should tell people to use factory pad shims if their pads can cook caliper dust covers.
Last edited by jasonrxeight; 05-16-2015 at 07:45 PM.
HPS are inadequate for ANY track driving. You cooked them at the track...and overheated the caliper seals......and you are surprised?
Brake caliper seals are a wear item at track temps...you will ned to replace them at least once a year.....or more if you track a lot
To condemn a whole manufacturer for using the wrong pads isn't logical
There is no pad that I have ever seen that you can use on the street and at the track if you are fast.....it's just one of those things
HPS's are inadequate for any driving to me. I almost rear ended someone.
As for dust boot melting, no if they didn't design the pads properly.
Like I said, if its normal to melt, it would melt all way cross not just part of it.
Factory pads have shims that cover the entire pad making sure the seals are not touching the base of the pads.
Hawks shim do not cover all the way. It's a design flaw.
Why not show photos of the pads and shims to illustrate your point? There must be something different about HPS, because the HP+ and DTC-30 pads I have been using have been just fine in that regard.
Also, a lot of people ignore the Hawk shims and just clean, grease, and reuse the OEM shim stack.
To dannobre's point, I keep seal and boot kits in stock should I need them. I track my car about a dozen times per year and rebuild my calipers about once per year. My dust boots never look perfect.
Chiming in with the HPS users, I have about 80,000 miles on several sets (There are a lot of track miles in there). I saw none of these issues. I did rebuild the calipers after about 120,000 miles. I was getting some dragging and the seals were kind of worn. That went away with the rebuild ($40 in little rubber parts). I can share that the car stops like a demon. My biggest track issue is over-braking. Others that have driven the car agree.
The incompatible transfer layer could be an issue, but if you turned the rotors, that should not be a problem. I wipe mine down with acetone. Lot easier than getting them turned, layer comes of nicely. They could be dragging, especially in the rears if not screwed all the way back in, and that will heat the rears and kind of remove them from the equation. What stability control, ABS and the proportioning valve do with the at information kind be kind of messy.
One think I can share is they HATE to be cold. There are tables out there that talk about the minimum temps. I found them when I switched to HAWK. I live in Florida, so it is not much of an issue, but my first drive in the high 20's with them were an eye opener when I hit the end of the street (stop sign). I add this because I think OP is in Nebraska. On a cold day, that first stop can be kind of interesting. I now drag the brake to the first stop sign if it is below freezing. The day is fine after that. Those tables helped me pick a pad that would work well for the majority of the temps I drive in.
Love to help more, what are the average temps you were seeing when you had issues? Also, if you did not get the old transfer layer off the rotors, it would coat the pads as well. Then the only option is sand paper to clean them back up.
Here is another chart, but it unfortunately does not include HPS or PC. I seem to remember PC fitting a curve just below OEM and HPS fitting a curve just above OEM on previous charts. Who knows what OEM means to them?
Last edited by Steve Dallas; 05-17-2015 at 11:00 AM.
That fits the old table I saw. OEM is kind of flat heading off the chart. Or, good a all temps. Most of the entry level pads kind of hit the axis down around zero. Kind of like summer tires. They do not work when cold. I learned that one on a very cold track morning. And, you need friction to get heat, if there is no friction, they just do not work.
One think I can share is they HATE to be cold. There are tables out there that talk about the minimum temps. I found them when I switched to HAWK. I live in Florida, so it is Love to help more, what are the average temps you were seeing when you had issues? Also, if you did not get the old transfer layer off the rotors, it would coat the pads as well. Then the only option is sand paper to clean them back up.
50-80F. Plenty warm.
I did turn then rotors before throwing on the HPS.
Like I said these pads are not near aggressive than factory pads.
When I put factory pads back in after Hawks, I didn't even clean the tarnish and the factory pads just took it all off after 500 miles.
I think you're drawing the wrong conclusions from the symptoms you're seeing. HPSs are my daily pads, I swap the out for track days though, because they get glazed. Never had a problem.
1) the braking performance. Can you show a photo of the pad surface? I have a strong suspicion you glazed them during track days or break-in.
2) black deposits. Totally normal with Hawk pads after heavy use, like track. It's pad material, and it's meant to be on there. If you continue driving on the street ( and your brakes aren't dragging), it gets spread around. I never had shiny rotors with any Hawk pad. At best a matte finish.
3) 'dangerous' stopping should have been your first indication that something is wrong. Broken in or not, the pads will stop the car adequately even cold, even in winter. So..something went wrong with the installation. Picture of the pad surface will tell a lot.
4) Your caliber seal isn't burnt, it's sheared off. Look at the remaining portion of it, it's mint. Either it got pinched or the piston is crooked in the bore and / or twisting while the brake is applied, which would happen if your brake was dragging. Are both sides' calipers damaged equally?
I think you're drawing the wrong conclusions from the symptoms you're seeing. HPSs are my daily pads, I swap the out for track days though, because they get glazed. Never had a problem.
1) the braking performance. Can you show a photo of the pad surface? I have a strong suspicion you glazed them during track days or break-in.
2) black deposits. Totally normal with Hawk pads after heavy use, like track. It's pad material, and it's meant to be on there. If you continue driving on the street ( and your brakes aren't dragging), it gets spread around. I never had shiny rotors with any Hawk pad. At best a matte finish.
3) 'dangerous' stopping should have been your first indication that something is wrong. Broken in or not, the pads will stop the car adequately even cold, even in winter. So..something went wrong with the installation. Picture of the pad surface will tell a lot.
4) Your caliber seal isn't burnt, it's sheared off. Look at the remaining portion of it, it's mint. Either it got pinched or the piston is crooked in the bore and / or twisting while the brake is applied, which would happen if your brake was dragging. Are both sides' calipers damaged equally?
Hmm the pad does look clean. Seems normal for the low mileage.
Symmetrical boot damage like that though, on both sides of the car. That's weird.
Also is that grease on the piston and dust boot? You're not supposed to put grease there. It shouldn't hurt anything if you do though.
I can't explain what's happening here, lol.
Hmm the pad does look clean. Seems normal for the low mileage.
Symmetrical boot damage like that though, on both sides of the car. That's weird.
Also is that grease on the piston and dust boot? You're not supposed to put grease there. It shouldn't hurt anything if you do though.
I can't explain what's happening here, lol.
Whats happening is the shim was too thin on the Hawks as a result the boots were touching the pad.
The lack of bite on the pads cause the pads to overheat which burnt the rubber.
The lack of bite is due to in compatibility between the pads and the rotor.
I've had HPS pads on for a while, with plenty of autocross time, and a track day. I loved the way they handled on the track. Never had any fade, and I could out brake all the cars I was behind. I like that they aren't aggressive for normal driving, but once they get hot they grip very nicely.
I've had HPS pads on for a while, with plenty of autocross time, and a track day. I loved the way they handled on the track. Never had any fade, and I could out brake all the cars I was behind. I like that they aren't aggressive for normal driving, but once they get hot they grip very nicely.
It's very weird too I did not get any braking force what so ever.
And the rotors just got coated with dark tarnish. After switching factory pads back in the tarnish went away and the rotors became shiny and smooth again just like before.
05-16-2015, 08:13 AM
