I'm surprised no-one else has picked up on Bellboy's party trick:
workshop.search-autoparts.com/_Can-You-Believe-This/video/486759/31710.html
It tells you how after about 1:40.
My cars were well under. How about yours?
I wonder what Bb's daily drivers are?
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>>I'm surprised no-one else has picked up on Bellboy's party trick:>>
I did, and thanked BB, My car is too new to need a test.
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I have seen disks in a worse state than this.
I guy I worked with came in with a big very very thin shim.
The part of the disk the pads contact with had completly detached itself because it was so thin.
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I picked up on it but wanted to find out how accurate it was and whether it varied with fluid type.
My Googling led me to this site - tinyurl.com/3yokmks
The limit both sites give is 0.3Volts.
My Focus is 0.06Volts despite being 11 years old and certainly not had the fluid changed for at least 5 years.
If the test is accurate then I should be happy but I'm still rather suspicious of the whole method.
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I think that the limit might just be being interpreted the wrong way.
If the voltage drop measured by the DMM [I assume on the diode test range] is high, that means the fluid is behaving as a good insulator - which you would expect of new fluid.
A low voltage drop - from fluid contaminated by water and/or copper, indicating the fluid is conducting effectvely would be what I would expect to read from old fluid.
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I just used the volts range, I presumed it's some sort of dielectric effect?
I got a reading of 0.11 on a car that had just had some fluid flushed through it, although not a complete change.
0.14 on one that last had a fluid change a year or so ago.
0.4 on the clutch fluid reservoir of an 8-year-old car that's never been changed.
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>> I just used the volts range, I presumed it's some sort of dielectric effect?
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That would give very random results as there's no voltage being pushed through the probes - they're just fluctuating in the way electronic multimeters do.
The diode test feature pushes a voltage through to test a diode, or ohms would work if you knew what kind of figure to look for.
One issue I see is that the amount of the probes that's inserted into the fluid, and the distance apart they are, will affect the reading to some extent - but I don't know if that would be significant or not.
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If we're measuring resistance, why not set the DMM to ohms which AFAIK is an absolute measure?
Voltage drop is all very well but doesn't that depend on the state of the battery?
Can anyone clarify?
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This must be a new technique? Last time my brake fluid was tested it was done by checking its boiling point SFAIK.
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The way I interpreted it, it's not a voltage drop - he was using that as an example of how to set the meter.
Negative lead of the meter goes to negative on the battery - definitive "earth" connection.
Positive lead of the meter goes in the soup.
The brake pipes are presumably not coated on the inside, and have a good electrical connection to the bodywork somewhere (ABS controller?).
The connector on the meter's lead is likely to be plated copper, with some scratches through to the copper.
I think you have an iron / copper battery with dubious electrolyte.
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Testing brake fluid for water content - Old Navy
