Drilled holes on break discs filling up and causing brake fade

[optimusprime]

I am you can buy 4x plastic shields to fit one on each disc before the wheel is replaced .. . They will stop this dust, no problem . Dont know why disc makers have these holes in them if there was a problem i am sure the discs would be solid instead of drilled

 

[rf065]

I am you can buy 4x plastic shields to fit one on each disc before the wheel is replaced .. . They will stop this dust, no problem

And it does this by stopping the airflow from the discs through the wheel and therefore restricts brake cooling.

 

[DSM10000]

I am you can buy 4x plastic shields to fit one on each disc before the wheel is replaced .. . They will stop this dust, no problem . Dont know why disc makers have these holes in them if there was a problem i am sure the discs would be solid instead of drilled[/QUOTE]

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They have holes because the manufacturer may claim "advantages" such as decreased un-sprung weight, (technically true but so little an effect as to not be worth mentioning, also there are claims of improved cooling.

By removing material you lower the overall thermal mass so this is tenuous in the extreme plus, if it was an advantage Formula 1 cars would have discs with holes, they do not.

The real reason is marketing as they are sold as "Sports brakes" as meaningless a claim as "Super foods" et al

 

[whitenemesis]

Holes improve wet braking and cold bite. Obviously not something remotely important to F1 as the discs are carbon composite, get and stay,very very hot

 

[Gazwould]

Two complely different applications , holes would crack for sure in F1 hense.

 

[Bellow]

The reason for drilling is.... if the dimensions (hole diameter and disc thickness) are correctly chosen, there is an increase in surface area and hence cooling. Everything else is myth.

 

[DSM10000]

Holes improve wet braking and cold bite. Obviously not something remotely important to F1 as the discs are carbon composite, get and stay,very very hot

Interesting re wet braking and cold bite. What helps with cold braking?

 

[whitenemesis]

The reason for drilling is.... if the dimensions (hole diameter and disc thickness) are correctly chosen, there is an increase in surface area and hence cooling. Everything else is myth.

Cooling is rarely an issue for road cars. The only time, possibly, is on long descents and then the holes help degassing on the pad/ disc interface.
As said, holes help wet braking by breaking up the water film.
Can't recall the reasoning behind increasing cold bite, possibly giving an edge for the pad to work on?

 

[DSM10000]

Cooling is rarely an issue for road cars. The only time, possibly, is on long descents and then the holes help degassing on the pad/ disc interface.
As said, holes help wet braking by breaking up the water film.
Can't recall the reasoning behind increasing cold bite, possibly giving an edge for the pad to work on?

Thanks.

I had heard of pad gassing but again thought this was only an issue under extreme braking and not with new pad formulation. In 30 plus years of driving I have only once suffered brake fade in a car, (a SAAB 9-5 Griffin 3 l Auto that had very little engine braking when lifting off) on a long series of descents, I pulled over and once the smoke had dissipated they were fine

 

[Neiltodd]

Thanks.

I had heard of pad gassing but again thought this was only an issue under extreme braking and not with new pad formulation. In 30 plus years of driving I have only once suffered brake fade in a car, (a SAAB 9-5 Griffin 3 l Auto that had very little engine braking when lifting off) on a long series of descents, I pulled over and once the smoke had dissipated they were fine

I had brake fade once driving a Daihatsu Fourtrak following a Golf GTi in the late 80s, had to back off and meet them later

 

[whitenemesis]

5 reasons for purchasing a drilled disc