A response- long
CQRT said:
You seem pretty adamant in your belief Mikey-- are you an engineering-type that would render your opinion better informed, or are you just out to see what kind of discord you can stir up on a seemingly innocuous subject? You seem to want to criticize the fellow simply for not blindly agreeing with your position.
If there's good science fine, but your way or the highway- it's not !
Yes, I am adamant in my opinion, and yes, I am an "engineering type". Thanks for asking. I have 25+ years seniority with world's largest manufacturer of aviation gas turbine engines, every moment of that fully engaged in some, or all of: assembly, test, design engineering, reliability engineering, field engineering, shop repair, field repair and/or customer service. Throw in 4 years of instruction somewhere in the middle of that. 15 of those years was heavily oriented towards monitoring the reliability trends of 40,000 individual gas turbine engines operating in 150+ countries around the world and reporting the stats (by requirement of the law) to the federal regulatory authorities. Not long into that job, you learn the difference between 'dependable' 'reliable' and 'durable'. Until you know the difference, stand clear.
Prior to that, I had ten years experience as a tech inspector for a nationally accredited motorcyle road racing organisation. Concurrent with that I held a professional motorcycle mechanics license with the AMA and regularly 'wrenched' with a team at Laconia NH and Daytona FL. Yes, that makes it the early 70's for those who are counting.
My first encounter with SS/teflon brake lines was in bike racing. Rules were 'not allowed'. Any bike that showed up at tech check was sent back to remove them. "Sudden failures" was the reason.
Next experience was a friend in Toronto who tried an experimental monocoque frame and used teflon lines throughout. A line fracture put him in the weeds, fortunately at low speed. I helped him make new lines out of good old TBW with OEM rubber lines from Honda IIRC
Most relevant experience was shortly after entering the aviation field. My first job as an apprentice was to test and calibrate fuel control units mounted on a huge test rig driven by a 75HP electric motor. All hydraulic and pneumatic connections to and from the units were with ss/teflon lines for easy of mounting and quick change over from one config to the other. After the third 'shower' I took in 1500 psi fluid following a hose burst, the local health and safety rep blew the whistle. The hose manufacturer was called in and informed all concerned that hoses of this nature, although aircraft quality, WERE NOT SUITABLE FOR INSTALLATIONS WHERE A HIGH DEGREE OF FLEXING AND VIBRATION WERE PRESENT ON A CONSTANT BASIS. He further explained that all hoses of this construction were subject to sudden failure (no sh*t says me), and NO non-distructive tests were considered adequate to recertify.
The solution was to replace all $3000. (1978 dollars) worth of hoses every three months.
Note that NO aircraft engine manufactured by this particular company has ever had (or will have ) ss/teflon flex lines.
Do I consider the subject 'innocuous' ? No. Not where sudden failure of the primary safety system of a high powered performance vehicle is concerned. "Innocuous" could be debating whether brand X brake pads vs. brand Y pads last longer. Brake pads wear out in a progressive manner that can be tracked, measured, plotted, analysed and most importantly removed from service before they cease to function.
SS/teflon brake lines (by all accounts) cannot, and therefore present an unacceptable failure mechanism with equally unacceptable consequences of the failure.
I suggested in my first post that the person inquiring do a bit of external research on the subject to get opinions from others with direct experience with these particular components. Others have since chimed in here with opinions that ranged from 'made no difference in brake feel' to 'I personally had a failure' with a smattering of 'no problems to date'.
I guess I fail to see why the debate goes on trying to justify a product that, by all accounts, appears to offer no improvements in performance (other than anecdotal quotes) yet introduces a new and serious failure mode where none existed before when using the OEM product.
Stirring up discord? Not my intent. Healthy debate that's woth the effort? In my book yes.
