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Discussion Starter #1
Hi all-

With all the talk of the StopTech BBK and now the Dinan/Brembo kit lately, I've been wondering about maintenance of these systems.

I was talking with my Service Advisor earlier in the week. He mentioned that our cars typically need "brake jobs" around 20,000 - 25,000 miles. I assume this means a replacement of the rotors, among other things.

With a BBK, what happens when you need a "brake job" at the dealer? What about replacing those drilled or slotted oversized rotors? The dealer obviously doesn't stock StopTech components.

Can anyone attest to typical maintenance requirements for BBKs used mainly ON THE STREET? (I've never been to a track before!)

A nice firm pedal and some big red calipers sound awful nice...

-Matthew
 

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MT JTN said:
With all the talk of the StopTech BBK and now the Dinan/Brembo kit lately, I've been wondering about maintenance of these systems.
...
A nice firm pedal and some big red calipers sound awful nice...
Good question. My 2001 has Brembo fronts, and was wondering what I should be on the lookout for. I do know that the brake-wear warning system is deactivated with a BBK, so I need to keep an eye on the pad wear.

Oh, and don't expect a firm pedal feel. The mushy feel drove me nuts for a while. After bleeding the lines and putting braided stainless lines on all fours, I heard that the soft pedal is just part of the tradeoff, due to piston design. Stops like gangbusters, though (whatever that means).

DaveZ - can I get Axxis Ultimate pads to replace those that came with the Brembos? They are 14" (355mm). Thx.

Best,
Bert
 

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FastFwd said:
Good question. My 2001 has Brembo fronts, and was wondering what I should be on the lookout for. I do know that the brake-wear warning system is deactivated with a BBK, so I need to keep an eye on the pad wear.
My stoptech kit retained the brake pad wear indicator. Not sure if the shop who did the install did something special, but the sensor is in a notch in the pad, driver side iirc.
Mike
 

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mottati said:
My stoptech kit retained the brake pad wear indicator. Not sure if the shop who did the install did something special, but the sensor is in a notch in the pad, driver side iirc.
Mike
Yes, the Stoptechs come pre-configured to accept the brake pad wear indicator.
 

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FastFwd said:
Good question. My 2001 has Brembo fronts, and was wondering what I should be on the lookout for. I do know that the brake-wear warning system is deactivated with a BBK, so I need to keep an eye on the pad wear.
The pad wear sensor doesn't work with the Brembo brake kit, however the StopTech kit uses pads with the proper notch to allow the sensor to work. So big brake kit doesn't automatically imply loss of brake wear sensor.
Oh, and don't expect a firm pedal feel. The mushy feel drove me nuts for a while. After bleeding the lines and putting braided stainless lines on all fours, I heard that the soft pedal is just part of the tradeoff, due to piston design. Stops like gangbusters, though (whatever that means).
Same thing here too. The StopTech brake kit uses smaller caliper pistons than the Brembo F50-based kit. Thus the pedal travel is reduced and the pedal feels MORE firm than stock, not less.
DaveZ - can I get Axxis Ultimate pads to replace those that came with the Brembos? They are 14" (355mm). Thx.
I wish the Axxis Ultimate came in that size! I did not like the Hawk HPS pads that came with my Brembo brakes, so I swapped them out for more agressive Pagid RS421 (Blue) pads. Lots of dust and more rapid wear. But the pedal feel improved after these were bedded in. There's still a dramatic difference in pedal feel between the Brembos on my car and my customers' 4-wheel StopTechs.
 

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MT JTN said:
Can anyone attest to typical maintenance requirements for BBKs used mainly ON THE STREET? (I've never been to a track before!)
I can answer this! In addition to big brakes on my dedicated track car (now it's Rebel1's track car!) I have upgraded the brakes on every street car I've owned for the last 15 years. Plus I maintain the big brakes on many of my local customers' carts.

Assuming you use the street pads that came with your big brake kit, you should expect longer pad and rotor life than your stock system. I can't tell you exactly how long in miles because someone in San Francisco will have shorter brake life than someone in Kansas. I had a customer in San Francisco order pads for his 740iL yesterday and he told me he goes through a set of front pads every 10,000 miles! Nothing wrong with his brakes. He just lives and works in the city (SFO) and if you've driven there, you understand.

Heat dramatically affects pad and rotor life. On a big brake kit, the larger rotors provide a bigger heat sink, so they don't get as hot as the stock brakes. And they are more efficient at shedding heat because they have more surface area for radiation cooling and they have better airflow through the rotors (between the two friction plates) for improved convective cooling. Cooler brakes mean less wear.

Replacing pads on these big brake kits is a breeze. For Brembo, simply pull two small cotter pins, then slide out the pad retaining rods and remove the spring clip. The old pads lift right out. The caliper pistons get pushed back in with a pair of large screwdrivers or with a specialized tool. Then the new pads drop in, the spring clip, retainers and cotter pins go back on. It took me longer to type this than it does to change the pads on one caliper.

For StopTech, you remove two 5mm allen screws from the caliper bridge and it lifts off. Then the pads are pulled out, pistons retracted, pads replaced, just like Brembo. Then the bridge goes back on and is bolted in place. Again, 5 minutes per caliper. Much easier than changing the stock pads.

Replacing rotors is a bit more involved. I put together instructions for the Brembo rotor replacement here: http://www.zeckhausen.com/Brembo/Rotor_Replacement.htm With the Brembo and StopTech big brake kits, you can expect to go through several sets of pads before needing to swap the rotors. (Again, this is assuming no track time.)

Some of my customers choose to buy a spare set of rotors and hats, pre-assembled with float hardware. When it's time to change rotors, they simply install the spare assemblies (or have their mechanic do it for them) then send me their old rotor/hat assemblies. I install fresh rotors and float hardware, then send them back.
 

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DZeckhausen said:
The pad wear sensor doesn't work with the Brembo brake kit, however the StopTech kit uses pads with the proper notch to allow the sensor to work. So big brake kit doesn't automatically imply loss of brake wear sensor.Same thing here too. The StopTech brake kit uses smaller caliper pistons than the Brembo F50-based kit. Thus the pedal travel is reduced and the pedal feels MORE firm than stock, not less.I wish the Axxis Ultimate came in that size! I did not like the Hawk HPS pads that came with my Brembo brakes, so I swapped them out for more agressive Pagid RS421 (Blue) pads. Lots of dust and more rapid wear. But the pedal feel improved after these were bedded in. There's still a dramatic difference in pedal feel between the Brembos on my car and my customers' 4-wheel StopTechs.
Thanks for the all the info, Dave.
Absolutely invaluable, as usual.

Best,
Bert
 

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Discussion Starter #8
DZeckhausen said:
I can answer this!

Some of my customers choose to buy a spare set of rotors and hats, pre-assembled with float hardware. When it's time to change rotors, they simply install the spare assemblies (or have their mechanic do it for them) then send me their old rotor/hat assemblies. I install fresh rotors and float hardware, then send them back.
Dave, that's what I was talking about.

But eventually, the rotors do need to be changed. I assume this is part of the dealer's routine at the 20,000-25,000 mile brake-job.

When this happens, what's the cost of replacement hardware versus the cost of replacement stock hardware?

Let's say I was going to buy a set of StopTech front-ONLY AND an extra set of whatever hardware I needed in anticipation of a brake-job (all street, no track time). What would the approximate cost?

Oh, and most importantly, given all street driving and no track time, let's call it moderate usage, about how long in terms of time or miles would one go between a brand new set up and switching the rotors out, etc.?

-Matthew
 

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MT JTN said:
But eventually, the rotors do need to be changed. I assume this is part of the dealer's routine at the 20,000-25,000 mile brake-job.
There's no such thing as "the 20,000 mile brake job". What happens is that a sensor in the left front inboard pad gets chewed up by the rotor when the pad thickness goes below about 2mm. A message "CHECK BRAKE LININGS" appears on the dash and the owner takes the car into BMW for service. This may happen at 25,000 miles or it may happen at 60,000 miles depending on the age/agressiveness of the driver and the topography and climate in which the M5 operates. For M5 owners with a 3-year free maintenance plan, the first rotor and pad swap might not be required in time to get the freebie. The 4-year plan that started in model year 2002 or 2003 (can't remember which) improves the odds of getting free parts from BMW.

When this happens, what's the cost of replacement hardware versus the cost of replacement stock hardware?
I don't know the cost of the stock hardware, but dealers typically charge $1000 - $1400 to swap the pads and rotors on an M5. You can do better by purchasing the parts at a discount from Pacific BMW and either handing them to an independent mechanic or doing the installation yourself.

For the big brake kits - StopTech replacement rotors are $245 each for plain or slotted and $305 each for drilled. The rotors come with new float hardware included. Brembo replacement rotors are $369 each for slotted or drilled, but you need to add $85 per rotor for replacement float hardware, since it is sold separately. Street pads for the StopTech brakes are Axxis Ultimate and cost $73. For the Brembo, they are Hawk HPS and cost $122.
Let's say I was going to buy a set of StopTech front-ONLY AND an extra set of whatever hardware I needed in anticipation of a brake-job (all street, no track time). What would the approximate cost?
You wouldn't do that for a street driven car. The first set of pads and rotors could last several years depending on your annual mileage and driving conditions. You have plenty of warning that it's time for replacement. And you would swap pads only on the first swap and not rotors. So it's possible that the rotors on your front big brake kit will last the life of your car. It just doesn't make sense to buy a complete set of hats/rotors and keep them on ice until you need them unless you are tracking the car.

That being said, a pair of StopTech replacement hats and rotors assembled with float hardware costs $899. For Brembo, the cost is $1,908. (Tha'ts not a typo!)
Oh, and most importantly, given all street driving and no track time, let's call it moderate usage, about how long in terms of time or miles would one go between a brand new set up and switching the rotors out, etc.?
That's very hard to say. It's like asking what happens when you install a CAI and a free flow exhaust. In theory, your gas mileage should improve with the installation of those devices. In practice, the change in intake and exhaust tone as well as the slight boost in power tends to make the driver more agressive and the result is usually LOWER gas mileage. Such is the case with big brakes. All else being equal, you should get longer life out of them than the stock components. In practice, you may find yourself braking later and harder, just becuase you can. The effect is more pronounced at the track where big brakes can chop seconds off your lap time, which means you are braking much harder than before when you were using track pads on stock hardware.
 

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Discussion Starter #10
Beautiful Dave. Clear and informative as always!

Thank you!

-Matthew
 
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