On 06/23/2011 08:00 AM, Scott Dorsey wrote:
> > wrote:
>> "Scott > wrote in message news:itvfi1>
>>> Problem is that this is very dependant on the electrodes being used.
>>> If you had a couple standard electrodes, though, you could do it
>>> accurately.
>>
>> I dont think even that would help this method, Scott.
>
> It's true that there's other stuff that will increase conductivity, but I
> think everything that will possibly increase conductivity is going to be
> something you probably don't want in your brake lines.
>
> But, unless you have calibrated electrodes and a calibrated volume,
> you can't get resistivity from resistance.
>
>> The most accurate method I know of for water in polyols is Karl Fischer
>> titration....and that is beyond the cost limitations and technology of most
>> people who want a value for water in polyols.
>
> That seems severe overkill for the application, and definitely not an
> easy kitchen job.
>
>> There are some test strips:
>> http://www.gwrauto.com/stripdip.htm
>>
>> that may be economical for shop use.
>
> Frankly, it seems easier to change it than to test it

ain't that the truth. while i'll take testing over superstition every
time, brake fluid, with its attendant seal swelling/degradation
problems, and known absorption profile, is simply not worth it - just
change every other year. testing may be useful for shops where they
have a new customer and an unknown service profile, but for an owner
that knows their vehicle's history, it's pointless.


> , although I realize
> some newer vehicles with ABS systems can make it more difficult to change.

that may have been the case when they first came out, but these days,
it's really not a problem.


> --scott
>


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