UFO brake question

[Steve Scalmanini]

No Q, Bernie.  I know you've had great luck with your UFO's but mine and 
many others hasn't been as good.  I follow your advice, though, to not 
replace them. 

Turning has always trued my UFO's to within .001" TIR and then each runs 
for 3-15 months before wobbling again.  I've never tried your shim 
technique but I'll give it a shot some time.  I made a tool over a 
decade ago to measure runout.  (Aluminum bar that holds a dial indicator 
on one end and can be clamped to the anti-sway bar with a Vice Grip.  I 
posted it's design once.)  So I'll try shims some time and post the 
results.

Have you ever tried steel shim-stock (available from machinist supplies 
- looks like a loooong feeler gage - available in plenty of 
thicknesses)?  An appropriate thickness could be cut and adhered 
adjacent to both sides of each appropriate hole in the mounting surface 
of the rotor, perhaps with a thin coat of Permatex (the alcohol-soluble 
brown goo.)  Then the shims might stay in place if/when the rotor was 
removed.

I've confirmed several times over the years what you posted years ago 
that UFO warpage can be felt in the brake pedal starting at ~ .002" TIR, 
and by the time it gets to .007" it feels like the front end is shaking 
apart. 

I've never messed with the heat-'em-up technique for fear of making them 
worse or some other aspect of Murphy's Law. 

Steve

PS:  My front-end rubber is still original at 245K so that's the next 
project on the car list. 


Sun, 11 May 2008 16:20:07 -0700, Bernie Benz wrote:
> What’s your Q? I’ll throw one back at you!
>
> Why do you think that they need repeated re machining? IMO, it’s a 
> waste of good material and the trueness derived for normal wear. Mine 
> at 225K have never been re machined, are dead true, and I believe will 
> remain so for another 250K.
>
> Bernie
>
>
> On May 11, 2008, at 3:29 PM, Steve Scalmanini wrote:
>
>> If you don't know where to get your UFOs turned (in San Jose, CA) from a
>> post years ago, it's on Chris Miller's site.
>> I have 3 extra sets and every 3/4/5 years I send or drop off the 6 not
>> on the car to get turned.
>> Steve
>> Ukiah, CA
>