Sharing............

I am in a middle of doing this ................ : https://mbworld.org/forums/e-class-w...it-brembo.html

The NEW ROTOR using oldie/used brake pad experiment showed some interesting result.

First the baseline, to show that the used brake pad is thin enough ( down from 16.5mm new to 13mm used ) now allows caliper piston to retract properly.
Run the car at idle RPM in D. Let wheel hub spin and see if there is any touching of brake pad to rotor which will cause heat.

Both Left and Right passed the 3 minute spin test. No touching and no heat.
Both L and R Rotors stay at ambient temperature

LEFT SIDE
C = caliper position. It is always towards car rear.
Hot spot on the right is the exhaust system.



RIGHT SIDE



The brake test, using right rear wheel.


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The temperature result of the above test, for both rotors.


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Too cold, that meant not enough friction created.

Lo and behold
Oldie brake pad wear pattern on new rotor showed how the condition actually was for my oldie rotor.
No wonder the braking has the "shudder" as per the video above.
The friction zone of the oldie brake pad is only at the sides and not entire surface. The green marker pen middle zone did not get "touched"

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I got curious, how much is this gap we are talking about ?

The best I can do to measure difference of thickness of the oldie rotor.
My best illustration of the oldie rotor. Thinner at the edge and fatter at the middle.




My tool maximum reach not the greatest, but decent , middle enough.


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Holy Cow, 0.05mm can make touch or no touch.




For-non metric dude


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If using caliper, must use light ray leak method



Tissue test, single layer only. Okey my caliper jaw is still good. This is new caliper.


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For rear brakes rotor x 2 pcs + brake pad set is cheap, MB genuine. For USA they are only under US$250 at good MB dealer online webstore.
Based on my car and this is so general in use for rear brake system :



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US$45 x 2 , so cheap .





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Let see the front if for my car , based on USA MB prices. Mine is the 4 pistons MB-Brembo caliper 344mm, not single piston caliper. Pads made by Akebono.
Brake pad not in stock at the moment , thus no price. But we can track Part Souq which sell higher than MB dealer.
I got whacked locally at MB Indonesia about US$950 for 2 front rotors + brake pad.... dugggh and this is 2 years ago.
MB USA at the most rotors x 2 = U$250. Brake pad set , US$150 = US$400, dang, such a good price.



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Part Souq in Dubai is never cheaper than USA's MB dealer online webstore.
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So there you go............

Change rotor too when changing pads = BEST

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More evenly spread? When you took the images the car was standing still...the caloric value of the dissipation would rise (as one would think the ambient temp was cooler than the rotors). The heat will in general dissipate towards the thing wtih the greatest caloric offset - in general, close meal items and then to the air (poor transfer to the air, in general). The heat will "soak" into the parts of the rotor with additional metals (and seem cooler to thermal imaging) than parts with air behind them (hollow parts). The draw from the metal areas (lug nuts, and metal the metal contact) will also have a great cooling appearance. In general when the caloric value dissipates to a larger structure (the wheel) it will seem to limit the temps as the wheel has a higher mass of metal (Aluminum, a faster thermal process metal) and dissipate to the materials in a more rapid fashion, showing a cooler over all signature.

Remember, energy can not be created or destroyed...it can only change form. Heat is energy.

 

Thanks for the information....

I think your reply suits better to my other thread : https://mbworld.org/forums/e-class-w...ml#post9242036

 

Odd, I thought that is where it was...you know how the forum will show other threads on the bottom of a thread.

 

Yes yes, I know what you meant.
I landed a wrong post too because of that ...