[Vwdiesel] Not Deisel, just brake bleeding hell on a VW bug question

[Erik Lane]

If you look at a material like metal, when it expands it generally
does so in a uniform manner. Think of a balloon being blown up. If you
have a dot on the surface, no matter where it is it will get bigger.
The same thing with a hole drilled in metal - it will get bigger as
the metal expands. The same thing for the inside of a brake drum - it
will expand as the metal expands. Everything expands in all
directions, but the net effect is an outward expansion at all points.

If you don't believe me you can do some research on it. When I first
encountered such a thing I was very unsure which would happen -
expanding inward or outward. I finally managed to find the math that
showed very conclusively that everything expanded. But in essence you
can just imagine a balloon. Even if you draw a circle and then blow it
up the whole thing will expand, even though the line of the circle
itself is getting thicker.

Erik

On Sun, Jul 25, 2010 at 6:27 PM, Tony and Lillie
<tonyandlillie1 at earthlink.net> wrote:
> Well, the drums on a big rig will expand to the point at which the linings
> won't come in contact, which is the danger of letting speed get too high
> down a continuous grade. However, on a car that's not a problem. But I'm
> still unsure how they tighten, but you may be onto something. Either way,
> I've experienced it, so I know it can happen.
>
> Tony
> ----- Original Message -----
>> In a message dated 7/24/2010 8:46:42 PM Pacific Daylight Time,
>> tonyandlillie1 at earthlink.net writes:
>>
>>> However, don't make them too tight either, as they will tighten
>>> even more and start draging once they heat up. I never did undedrstand
>>> this,
>>> as the drums should expand, but I guess the shoes expand even more.
>>
>>  Guess it can expand in as well as out (thickness).  Maybe unlike
>> a bearing, which gets bigger with heat, the closed over side keeps
>> the ring of the drum from growing so much and the expansion goes
>> into the thickness?
>>    Loren
>
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