Is mixing brake pad brands a problem?

[crowtrobot]

My track setup has been PFC08s up front and EBC yellows in the rear, since the PFC rears I ordered didn't quite fit the caliper correctly.

There's a little bit of wiggle under heavy braking in certain situations on-track, but for the most part the car behaves well. I wouldn't worry about it too much unless you go with dramatically different compounds.

Don't notice any difference at all on the street.

[JimD]

How soon you need pads is partially a function of how long you are will to see a red "Brake" on your instrument panel. Once you hit the wear sensors you cannot turn off the light except by replacing the sensor. It is several millimeters thick - might be as much as 5 millimeters - so you will get the light a long time before the pad is worn away.

I tied my rear sensor up behind the inner fender liner in the rear to stop this but I put the front one back after looking for a convenient place to tie it up.

[bmw1racer]

Originally Posted by bmw1racer

This is an interesting discovery that I don't think anyone has ever pointed out regarding the brake pads (at least for the 128i): I received the Akebono pads today and the fronts (13mm) are thicker than the rears (10mm).

Don't you guys think it's odd that the front and rear pads are of different thicknesses? Doesn't make any sense at all.

[blue135]

Well, if I was charged with doing this design and I had concerns about owners/shops mixing brands of pads when replacing, the first thing I would do is try to make sure fronts and backs wear out at same time. And since we know weight and weight transfer influences brake wear and most people drive forward most of the time (meaning when stopping weight transfer is to front), I would put more brake pad (area and thickness) on front and less on rear to create a situation where front and rear pads might wear to minimum thickness at roughly same time.

[bmw1racer]

Originally Posted by blue135

Well, if I was charged with doing this design and I had concerns about owners/shops mixing brands of pads when replacing, the first thing I would do is try to make sure fronts and backs wear out at same time. And since we know weight and weight transfer influences brake wear and most people drive forward most of the time (meaning when stopping weight transfer is to front), I would put more brake pad (area and thickness) on front and less on rear to create a situation where front and rear pads might wear to minimum thickness at roughly same time.

That makes perfect sense, though it was a shock to me having known in the past (and expecting) the pads to have the same thickness from the beginning.

I guess I'll just sit on these Akebono pads until I really need them.

[nachob]

Originally Posted by bmw1racer

Checked my brake pads today and my rears worn considerably more than the fronts (which seems odd).

I'd like to replace the rears with a different brand (maybe Akebono) than the fronts (original stock). Is this inadvisable?

Absolutely not a problem front to back. Just not mixing right to left!!

Actually BMW mixes brake pad brands themselves. My E46 ZHP had Pagid BMW branded fronts and Textar BMW branded rears.

Personally, I recommend Textar for the street. They can be slightly noisier than Pagid, but have excellent cold bite which I love. The Pagids are quieter but they don't bite as well cold. Once warmed up they are about the same. It's just that in the morning when I'm driving to work and the little 5 year old kids runs in front of my car, I like the instant cold bite of the Textar. Same when you are driving on the highway and exit an offramp, instant bite. BMW pads are also good with cold bite. Everyone wants to go with track pads on the street but you are not on the track where the pads are hot all the time. you want the pads to work immediately when cold. Don't misunderstand, the Pagids are not track pads they are also excellent pads, but the Textar compound is just tuned for a quicker, more reassuring cold bite. Just take extra effort to lube all the contact points to prevent squeal. The Pagids are more forgiving in this respect, but I love cold bite.

Best wishes.

[MightyMouseTech]

Originally Posted by bmw1racer

Don't you guys think it's odd that the front and rear pads are of different thicknesses? Doesn't make any sense at all.

Pretty much every car is like this. Rear calipers are smaller, so less room for thicker pads.

[NorthernDancer]

Originally Posted by nachob

Absolutely not a problem front to back. Just not mixing right to left!!

Actually BMW mixes brake pad brands themselves. My E46 ZHP had Pagid BMW branded fronts and Textar BMW branded rears.

Personally, I recommend Textar for the street. They can be slightly noisier than Pagid, but have excellent cold bite which I love. The Pagids are quieter but they don't bite as well cold. Once warmed up they are about the same. It's just that in the morning when I'm driving to work and the little 5 year old kids runs in front of my car, I like the instant cold bite of the Textar. Same when you are driving on the highway and exit an offramp, instant bite. BMW pads are also good with cold bite. Everyone wants to go with track pads on the street but you are not on the track where the pads are hot all the time. you want the pads to work immediately when cold. Don't misunderstand, the Pagids are not track pads they are also excellent pads, but the Textar compound is just tuned for a quicker, more reassuring cold bite. Just take extra effort to lube all the contact points to prevent squeal. The Pagids are more forgiving in this respect, but I love cold bite.

Best wishes.

Very well said nachob; I would also like to point out that "racing" brake fluid should NOT be used in street cars. Cannot remember exactly why.

[tracer bullet]

Originally Posted by NorthernDancer

Very well said nachob; I would also like to point out that "racing" brake fluid should NOT be used in street cars. Cannot remember exactly why.

I've read that it has a higher boiling point but is more likely to absorb water.

I can't tell you if this is remotely true or not, never looked into it.

[nachob]

Originally Posted by tracer bullet

I've read that it has a higher boiling point but is more likely to absorb water.

I can't tell you if this is remotely true or not, never looked into it.

Yes but if you stay with DOT4 which is what comes with our cars and you change 2 years or less you are ok. DOT 5 racing fluid not recommended for street and also doesn't mix well with DOT4. Just use good DOT4 fluid.

[nachob]

I guess while we are on roll, we have covered pads and fluid. Now let me cover rotors. They are not all the same. Rotors and Pads work as a unit. Pads are designed to work with a certain composition rotor. If you stay OEM rotors like Zimmerman and ATE you will be fine. I have used Textar branded rotors and they seem OK too but rotors have different levels of carbon in them and they will affect braking performance. I learned this the hard way with my oft told story of my Legacy GT that had outstanding brakes but all four rotors warped on me. Being less experienced, I assumed that the excellent braking was the pad compound so I ordered brand new front and rear Subaru OE pads. I normally would've ordered the matching Subaru rotors but since they had all four warped, decided to buy another brand. I ordered four Brembo rotors from tire rack. Immediately as I took off the first rotor I noticed the Brembo rotor was much lighter than the Subaru one I took off. As I said before, being younger and dumber, I thought, great! Lighter rotors, less unsprung mass, etc. The brembos also looked less iron-y, more like aluminum than cast iron in a weird way. Again, oh cool, they will rust less!

So I finished all four corners and set about bedding the brakes, etc. There was no bite. I waited...1000, 200, 300 miles...no bite. The car stopped, but it no longer had the excellent brakes as before. Finally 500 miles, I had enough. I had a good relationship with my Subaru dealer and they changed out the front pads for a new set. I swapped them and again waited another 300 or so miles....no bite. Finally, being a technical person I determined the only other thing I changed was the Brembo rotors. I disliked the braking so much that I said what the hell and went back to the dealer and bought two new front rotors just to experiment. I put them on the almost new Subaru front pads.....and bam! Excellent braking back! It was good enough that I left the brembos in the rear but ended up throwing away the fronts with only 500 miles.

So if you are keeping your OE Rotors, just make sure they are not at the minimum thickness. Here is my take on rotors:

Zimmerman coated, my favorite. The also look great for a long time.
ATE coated, also OK, but like Zimmerman more.
ATE uncoated... They work just as well as coated but look awful in a month, they rust and look bad quickly.
TEXTAR rotors, not sure who makes them but they worked fine with in my E46.
Brembo, I had the bad subaru experience. however, I am sure that if I would've used a pad compound that Brembo recommend, it probably would've been fine but when you can get deals on Zimmerman or ATE, I just don't see the point of Brembos. Finally, Brembo makes several grades including cross drilled etc. I am referreing to bottom end replacement rotors.

BMW dealer sells brake pad paste for about $1-2 a pack. It works very well. One pack will do a set of pads. Make sure you grease all metal to metal contact points and make sure you don't get any into the pad or disk face.

[bmw1racer]

Originally Posted by MightyMouseTech

Pretty much every car is like this. Rear calipers are smaller, so less room for thicker pads.

Not absolutely sure, but I could've sworn that the front and rear pads on my E36 were the same thickness...

[nachob]

Originally Posted by bmw1racer

Not absolutely sure, but I could've sworn that the front and rear pads on my E36 were the same thickness...

It happens sometimes that thickness is
The same but I nowadays they vary. Back in The E36 day cars still had solid thinner disks in the rear and thicker vented ones in front. So you could have a meatier pad with a thin disk. Nowadays most rear disks are vented like the font and a little thicker. The rear brakes also work less so you can have less meat on them and last longer than fronts that do 80% of the work. So you both are right I'm a way but a little less meat is common these days.

[MightyMouseTech]

Originally Posted by NorthernDancer

Very well said nachob; I would also like to point out that "racing" brake fluid should NOT be used in street cars. Cannot remember exactly why.

Many racing brake fluids are only rated DOT 3, but have very high dry boiling points. They are only rated a DOT 3 because their wet boiling point is quite poor. So they start off incredible, but drop off quite quickly, so they must be flushed often. Not a problem for race cars.

The OE BMW fluid is a low viscosity DOT 4. The low viscosity allows the ABS/TC to work faster, especially in cold climates, and the DOT 4 rating means it does not drop off as fast as it ages and absorbs moisture.

[Happy Jose]

I have the Akebonos, front & back, on my Mercedes, and they are virtually dust free, that is you don't see any visible stuff on the wheels. They work well, but they don't have the bite of the OEM pads. Customers have complained about the black brake dust, but Mercedes refuses to change them.

I wish I could get the Akebonos for my 135i, but they don't make them. I replaced the OEMs early with Hawk Ceramic Pads, yellow box, front & rear. They work very well but throw off a tiny bit of dust.

I still have the OEM pads, and the fronts have the same thickness as the rears. I think the wear on your rears is a dragging hand brake. You need to lubricate the cable or maybe replace it.

[nachob]

Originally Posted by Happy Jose

I have the Akebonos, front & back, on my Mercedes, and they are virtually dust free, that is you don't see any visible stuff on the wheels. They work well, but they don't have the bite of the OEM pads. Customers have complained about the black brake dust, but Mercedes refuses to change them.

I wish I could get the Akebonos for my 135i, but they don't make them. I replaced the OEMs early with Hawk Ceramic Pads, yellow box, front & rear. They work very well but throw off a tiny bit of dust.

I still have the OEM pads, and the fronts have the same thickness as the rears. I think the wear on your rears is a dragging hand brake. You need to lubricate the cable or maybe replace it.

Americans need to understand that when BMW and Mercedes makes a car that will end up cruising in the autobahn at 120 mph and needs to hit the brakes hard when cold they need the car to stop or someone will die. It is hard to make a brake pad that works well but doesn't create dust. If you make the pad too hard so it won't turn to dust it will glaze and affect performance. We don't drive as fast here in the US but you have to understand that their priority is to be able to consistently and reliably stop the car from high speeds with cold pads. I also used to get annoyed with the dust until I did Euro delivery and spent 3 weeks driving there. I recall cursing at 120 mph and having some Little car from Eastern Europe pull out onto the passing lane to pass a truck. As I stood on the brakes I was thanking god for all the beautiful brake dust coming out the front wheels. Some goes for daytime running lights that I thought were just some government bs thing until I was on the autobahn and was going to pass a truck. I glanced at my rear view mirror and just see car lights far away behind me. I paused as a 911 passed me going about 180 mph. So there are trade offs .

My wife's 2008 gti brakes were super clean but no cold bite. Changed them and much happier.

As far as Akebono pads go read my thing about rotors. It's possible alwbonos would work well with a different rotor. That is why I say if you use OEM European rotors like Zimmerman, ATE then they will most likely work better with OEM brake pads like Textar, Pagic, ATE

[MightyMouseTech]

Originally Posted by Happy Jose

I have the Akebonos, front & back, on my Mercedes, and they are virtually dust free, that is you don't see any visible stuff on the wheels. They work well, but they don't have the bite of the OEM pads. Customers have complained about the black brake dust, but Mercedes refuses to change them.

I wish I could get the Akebonos for my 135i, but they don't make them. I replaced the OEMs early with Hawk Ceramic Pads, yellow box, front & rear. They work very well but throw off a tiny bit of dust.

I still have the OEM pads, and the fronts have the same thickness as the rears. I think the wear on your rears is a dragging hand brake. You need to lubricate the cable or maybe replace it.

The parking brake is separate from the rear stopping brakes.

[Happy Jose]

Originally Posted by MightyMouseTech

The parking brake is separate from the rear stopping brakes.

Are you sure about that? I found this under "BMW 135i handbrake repair":

The parking brake cable is held in a fixed position, and when the parking brake lever is pulled, pressed, or electronically engaged, the cable is pulled tight. For disc brake systems, this tension presses the rear brakes pads into the rear brake rotor, or, for drum brakes, the rear brake shoes will be pressed into the rear brake drum. Many modern vehicles with rear disc brakes have an auxiliary drum brake inside the brake rotor that is actuated by the cable. This protects the service brakes if the parking brake is left engaged while driving.

[JimD]

If you parking brake works (as it does in my e88) and you have rear discs, then there is a separate drum brake for parking. I guarantee it. You cannot generate enough pressure to engage a disc brake with the parking lever.

My old Fiat 124 spider tried to use the rear disc brake for parking and it didn't work at all. It was a fun car, when it ran (which wasn't terrible often).

I don't think any current cars try to use the rear disc brake for parking.

[tracer bullet]

Yep you're right it's a separate set of arc shaped shoes inside the drum / center of the disc.

My Probe GT had a setup too where it used the "normal" pads, but it would seize once in a while, making me do a semi-annual cleaning and relubrication on it.

[MightyMouseTech]

Originally Posted by Happy Jose

Are you sure about that? I found this under "BMW 135i handbrake repair":

The parking brake cable is held in a fixed position, and when the parking brake lever is pulled, pressed, or electronically engaged, the cable is pulled tight. For disc brake systems, this tension presses the rear brakes pads into the rear brake rotor, or, for drum brakes, the rear brake shoes will be pressed into the rear brake drum. Many modern vehicles with rear disc brakes have an auxiliary drum brake inside the brake rotor that is actuated by the cable. This protects the service brakes if the parking brake is left engaged while driving.

Uhhh, I'm a BMW Tech. Pretty sure.

[Happy Jose]

Well if the rear pad are wearing faster than the fronts, something is causing the rear pads to engage the rotors. Another idea is the pad material in the rears is softer than the fronts. Maybe the OP has a mixed set of pads, or the pads are different thicknesses to begin with?

BTW, you can mix pads as long as they are the same on the axle. How well they'll work will require some experimentation.