[Grady Clay]

Bill,

I don’t remember if you and I (and others) have had this discussion but here goes.

I think there should be some flex in the hydraulic brake system. As each tire rotates, the grip isn’t perfectly consistent around the perimeter. The road surface isn’t perfectly consistent. The grip of the pad on the rotor isn’t perfectly consistent.

When braking at the limit you want to control the tire slip at, say, 98% of road speed. As the combination of factors conspire to lock up a tire, you have to modulate the brake pressure. Your foot is capable of perhaps 2-3 Hz max – certainly not high frequency. Some flex in the hydraulic system will tend to “average out” the imperfections.

I will assert that a perfectly rock solid hydraulic connection is more prone to tire lock-up at the limit of braking than one with some “sponginess.”

I feel this equally applicable for a track 911 with race slicks or DOT track tires as on the street when a soccer mom pulls out in front of you with a mini-van full of little girls.


On race cars there is the issue of exceedingly high temperatures at the caliper causing sponginess. Anything that can be done to maintain the brake function is good. Porsche works the issue with bigger and better brakes. Yes, Porsche uses covered SS hoses on the race cars.


I am in favor of OEM rubber hoses for the above and other reasons. I think the most important are in the links that Bill listed above. To summarize:
Dirt getting between the Teflon tube and the SS braid.
Failure at the connection between the hose and fittings.
Inability to inspect for kink damage.

I have never seen a failure of a rubber brake hose other than from old age or from crash damage.

The best reason to stick with OEM Ate rubber hoses is they work just fine and are inexpensive. Available from our host.


Best,
Grady