1980 floating brakes very noisy

[aseem]

I had to replace the "intermediate" alu disk (hats) that holds the floating brake disk on the front brakes of my 1980 Turbo. Partly beacuse they were badly corroded, and partly beacuse last time I changed my disks, several of the screws snapped and I had to drill and re-thread. That job wasn't perfect....

Since the genuine Porsche article is very expensive, I found some at VCI with a special floating T-lock that came from Coleman Racing. Beside the fact that they came with non-metric screws and nuts, and that I over-torqued these so I had to replace them, the solution seems to work. The only thing is that the brakes have become very noisy. The disks clatter in their mounting when driving, but when I use the brakes however, they are quiet. I have read that floating brakes are more noisy, but I always thought that this was during braking. My old setup was quiet, and never made a sound.

I have later discovered that Rebel Racing has a similar product at a much lower price. I don't know if they use the same T-locks or a similar system.

Anyway. Any experience out there with 78-80 floating 930 brakes in general, and with replacement hats in particular is greatly welcome.

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[jwasbury]

There is another current thread on the floating rotors right now>

http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/776872-floating-rotor-issue.html

Yes they are noisy as HELL when you are rolling down the road. The noise stops when you step on the brake pedal because when the rotor is clamped by the brake pads, it can't bang around in the hats anymore. I'm betting that all the Doctors, Lawyers, and Dentists who bought these cars new as status symbols back in the day complained about the noisy rotors, and I'd guess thats partly why they were eliminated.

Take a look at the thread in the link (where you will see a link to another thread on the topic that I started a few years back). There is a way to stop the rotors from floating if you want the noise to stop.

[aseem]

Thanks for the good link. I will be continuing your thread, and post my comments and questions there

[spence88mph]

"My old setup was quiet, and never made a sound." Could that be because of the dirt, brake dust etc build up reducing the play? I had fully floating rotors on my motor bike, I loved the sound, meant they were working. I can imagine it being annoying in a car though...

[David]

I'm replacing the disks on my '79 930 and there's a lip on the ring that bolts on top of the disk. It appears that if the lip faces the disk it would hold it tight and if the lip faces away from the disk they would be full floating. Is this correct?

[David]

I was informed that the lip on the bolt ring is to make them floating or non-floating. Since the car is pretty loud already I opted for full floating.

On the picture below you can see a little lip just outside the 12 bolts holding the disk. If that lip was facing the other way it would hold the disk tight so it wouldn't float. I couldn't find new locking washers so I went with safety wire.