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Thought you might appreciate that I was able to eliminate my pulsating rotors by removing the brake dust from the cross drilled holes - especially on the inside surface of the rotors (i.e. contact area facing the wheel well).
A few weeks ago, I decided to replace the pads with the ceramics with the hope of generating less dust. As soon as I removed the rotors I was able to see, very easily, the built up brake dust in the cross-drilled holes - especially the first couple of holes closest to the inside diameter of the contact area. Almost every hole along the ID was packed full with dust.
Since the brake contact surfaces appeared to be in overall good condition, I proceeded to clean out every hole with a twist drill that was about .005 under size so as to remove as much as possible. I cleaned the holes on both contact surfaces and it went quickly. Installed the Akebono pads and set them in.
Almost a 1000 miles on 'em with some moderate grade hill driving and nuttin' but smooth braking action.
Would like to know your findings on your brakes.
Good start to the weekend.
Agree, cleaning them holes does work.
I use air blow gun and it clean good, but I am sure your method clean even better but much more work.
What I hate the most about these holes are not only the dust. It is the holes themselves when they rust* ( *car not being used say 30 days ) , the holes edges started to form rust which
grow above the hole outer diameter and into the friction territory of the brake pad. Over a long period of time, the brake pad wear pattern and the rotor wear pattern will get un-even.
Like below :
Now I learnt a simple but useful trick. If I wash my car and clean the wheels + brake system, I have to drive it out to dry these brakes. Using airgun can not blow dry enough the brake.
Usually I can leave my car un-touched for a week after car washing because I don't go out at all, I am kinda retired and work from home.
1 week is enough to cause my brake rotor to lock up due to those rust left growing after washing the wheels + brakes. So when the car first move, we can hear that brake-crack sound, from rust release
Now unless my wheel is very dirty, I do not spray lots of water on the wheel + brake, I use wet cloth with Simple Green cleaner to clean the brake dust, that is all and this help prevent the rust,
for someone like me who does not drive the car everyday.
See new rotor below, the nice tapering of the holes would be gone if the rust eat them
Supposedly brake pad "dust" is needed to make brake pad contact to rotor better, something like that. I forgot what the techy term for it.
Those holes become inteference, they probably rob the brake dust too
Anyway, I hate them holes. If I were able to avoid buying genuine MB rotor from MB Indonesia and get a a known good aftermarket rotor without holes, I would do so.
Importing 2 brake rotors is too expensive on the shipping by UPS/Fed-Ex because each is 12KG or so, otherwise I probably would have imported them hole-less ones from USA or Europe.
On the outer hubs part of the rotors !
Choose life , choose no rust .
Either choose a good rotor with a robust paint finish or add a decent paint a week before fitting , I did this 9.5 years back on my other car and still wot no rotor hub rust .
Cast iron, that rust.
Some rotors are painted, or galvanized, what makes the central hub rust-free (to some degree).
Where I live rust never happens, so I don't care about paint on the rotors.
Can't see rotors past my monoblocks anyway.
Thought you might appreciate that I was able to eliminate my pulsating rotors by removing the brake dust from the cross drilled holes - especially on the inside surface of the rotors (i.e. contact area facing the wheel well).
A few weeks ago, I decided to replace the pads with the ceramics with the hope of generating less dust. As soon as I removed the rotors I was able to see, very easily, the built up brake dust in the cross-drilled holes - especially the first couple of holes closest to the inside diameter of the contact area. Almost every hole along the ID was packed full with dust.
Since the brake contact surfaces appeared to be in overall good condition, I proceeded to clean out every hole with a twist drill that was about .005 under size so as to remove as much as possible. I cleaned the holes on both contact surfaces and it went quickly. Installed the Akebono pads and set them in.
Almost a 1000 miles on 'em with some moderate grade hill driving and nuttin' but smooth braking action.
Would like to know your findings on your brakes.
Good start to the weekend.
Not had this pulsing problem with my M-B or any car, that is the pulsing due to plugged holes in the brake rotors.
But I bought a low miles used Porsche 996 Turbo with good thickness rotors and pads but with all the holes filled with brake dust/rust.
I went around the car with a round file and removed all the stuff from every hole.
i switched to zinc coated slotted only rotors, no rust on the cooling vanes which improves longevity the most with proper heat distribution. Original MB drilled were all grooved, didnt really pulse but weren't right either.
The painting thingy looks good. I may want to paint mine if it has not developed any hard to remove rust at the inner vented area
The nice photo from Gaz made me itchy fingers wanna work hahahah
IMHO, the drilled rotors used on the E350 'sport' models, the drilling is purely cosmetic and serves no useful function. you can interchangably use the undrilled rotors rom a E350 'luxury'
IMHO, the drilled rotors used on the E350 'sport' models, the drilling is purely cosmetic and serves no useful function. you can interchangably use the undrilled rotors rom a E350 'luxury'
that's for sure!
The only purpose of these stylish drillings is to reduce disk surface and shorten useful life.
The ugly wear grooves tell the whole story. Some people swear by looks
Last edited by CaliBenzDriver; 06-20-2022 at 03:58 PM.
The drilled rotors are to DRILL our wallets..... ha ha ha.
Its extra cooling effect is useless for us and to minute a difference from test I seen.
The holes (or grooves) are not there for the extra cooling but to deal with outgassing from the pads under severe braking.
While vehicles sold in the US probably don't benefit from this -- unless they are tracked -- vehicles sold in other countries where higher speed limits are permitted do.
In Germany I understand is to when running at high speed on the autobahn and a vehicle pulls out into the passing lane in front a line of vehicles traveling at speed is to slam on the brakes and let the ABS sort it all out. In this case every bit of braking margin is invaluable.
There might be some benefit too when driving in wet weather the holes/grooves can give any water on the discs a way to leave the area between the pads and discs.
IMHO, the drilled rotors used on the E350 'sport' models, the drilling is purely cosmetic and serves no useful function. you can interchangably use the undrilled rotors rom a E350 'luxury'
+1 indeed you can install the plain rotors and they're less expensive. You'll save $74 ($37 x 2) purchasing the plain rotors
The holes (or grooves) are not there for the extra cooling but to deal with outgassing from the pads under severe braking.
While vehicles sold in the US probably don't benefit from this -- unless they are tracked -- vehicles sold in other countries where higher speed limits are permitted do.
In Germany I understand is to when running at high speed on the autobahn and a vehicle pulls out into the passing lane in front a line of vehicles traveling at speed is to slam on the brakes and let the ABS sort it all out. In this case every bit of braking margin is invaluable.
There might be some benefit too when driving in wet weather the holes/grooves can give any water on the discs a way to leave the area between the pads and discs.
I recalled on the out-gassing thingy...now that you mentioned it. Thank you.
I sometime drive fast enough to benefit the holes for outgassing, in fact that is how my brake pad got overheated at the track, fun-driving only.
200-100 KM/H near maximum breaking. I have to admit, the brakes did not fade in 3 laps and is a good achievement for standard brakes, albeit mine is the sportier 344mm 4 pistons, code 950.
06-17-2022, 07:12 PM
