[Fot] TR6 Porterfield R-4 Rear Brake Shoes - Carbotech relining

[yellow04]

My issues with Carbotech has not been the quality of the pads, it has 
been the shoes for the rear drums. I have had a couple of failures where 
the lining breaks up at the top or bottom edge, and once it starts 
crumbling, it is game over. I got to the point where I was mixing and 
matching shoes from different sets to actually get 4 shoes to wear out 
evenly.

Last year there was a thread here about running stock linings on the 
rear shoes, and the first thing in my head was that's nuts. But taking 
into account where those racers were finishing, I decided the worst 
thing that would happen is I needed to swap brake shoes in the paddock.

OK, I didn't go with the Moss Motors "who knows where they came from" 
shoes, I went to Rock Auto and spent all the money on a set of genuine 
Raybestos shoes, currently available for a whopping $32 plus shipping. I 
ran them for the first time at Summit Point last weekend and they seemed 
fine. Obviously, until I put eyes on them the jury is still out, but I 
really didn't think I could tell any difference in stopping power. Most 
importantly, my lap times were OK and consistent.

Thinking I probably had less coefficient of braking, I did nudge the 
balance bar a tad to the rear, and after the first session where I did a 
completely crap job of bedding them in, I never thought about them all 
weekend.

Henry

On 2024-05-23 10:36, DAVE HOGYE via Fot wrote:
> I used Carbotech a few times for front pads.  I had lots of problems
> with them.  Quality control is/was terrible.  The backing plate was
> ground down to the friction material at the sides of the pads and they
> were not square.  So, there was far to much clearance in the caliper
> slot.  This caused the piston to torque once the brakes were applied.
> This makes the pads wear at an extreme angle and the pistons were
> leaving a witness mark in the bore from the induced torquing and side
> load.  The hot friction material was making contact with the caliper
> casting.  I talked with Carbotech a few times about this and they were
> completely defensive and said they sell a lot of these pads and no one
> ever complained about this problem before.  They were not willing to
> check quality control or make them correctly.  I took many photos and
> some video of exactly what was happening and made a direct comparison
> to standard pads and Hawk pads.  The standard pads were NOS from a
> quality manufacturer, which I can't recall at the moment.  Standard
> backing plate have a pretty tight fit in the caliper.  I think I found
> .010" clearance.  I found that the Hawk pads have very consistent
> production quality.  So I switched to Hawk.  I did like the feel of
> the Carbotech pads, but they really caused problems.
>  I'll share some photos and later.