Doing my own brakes (97 Accord) - need some advice

"*" > wrote in
news:01c7f79c$e6bf3d00$ce90c3d8@race:

>
> ----------
>> From: Tegger >
>> Newsgroups: rec.autos.makers.honda; rec.autos.tech; rec.autos.misc
>> Subject: Doing my own brakes (97 Accord) - need some advice
>> Date: Friday, September 14, 2007 9:07 PM
>>
>> "*" > wrote in
>> news:01c7f6ca$f811eee0$0c91c3d8@race:
>>
>>
>> >
>> > Some anti-seize compounds, those intended for oxygen sensors for
>> > example, contain glass beads. What sort of lubrication do you
>> > suppose glass beads provide?
>>
>>
>> First post doesn't seem to have "taken". Repost follows:
>>
>> The beads roll, to prevent seizure of the sensor?
>>
>>
>
> Don't confuse "seizing" with "galling."
>
> In this case we use the following descriptions......
>
> Threads "gall" in motion. Dry threads need lubrication to keep metal
> from transfering from one side to the other.



It has been my impression that galling was a phenomenon most commonly
experienced between metals that were close in hardness. In other words, if
one metal was significantly softer than the other, galling wouldn't occur
for the reason that the softer metal would simply smear instead of balling
up.



>
> Threads and components "seize" while sitting still - often due to the
> properties of different metals reacting to heat/water/exhaust
> chemicals/galvanic activity/etc.



And simple surface-texture embedment. From what I've been told by an
engineer at BoltScience, embedment is the primary reason that loosening
torque can be several times what's applied while tightening.



>
> Threads/components are "seized" by rust and corrosion. You need an
> anti-seize compound that works to prevent this - not lubricate the
> components.



Oils are not compatible with water. If oil is present, water cannot
generally react with the metal. I have found that just about any kind of
oily substance will keep rust off the threads, provided it does not wash
away.

I have found (after a lifetime of living in the Rust Belt) that rust rarely
penetrates more than one turn of thread. It's corrosion of the head to its
mating surface that makes such bolts hard to remove. If the bolt goes into
a through hole, the end thread of the bolt will seize at its bottom turn,
which is why these often need to be drilled out.



>
> The use of anti-seize has increased in direct relationship to the
> increased use of aluminum components with steel fasteners, and other
> different metal interactions in the modern automobile.
>
>


I wonder why my car has absolutely no substances applied to any of its
fasteners that go into aluminum holes? I guess the bolt itself may have a
plating or wash that consists of an anti-seize?
Toyota's OEM spark plugs that were intended for 100K mile intervals used to
be cadmium plated, to prevent seizure. I'm told they've replaced the
cadmium with something else that's supposed to be more "environment
friendly".

--
Tegger

Tegger wrote:

> "*" > wrote in
> news:01c7f79c$e6bf3d00$ce90c3d8@race:
>
>
>>----------
>>
>>>From: Tegger >
>>>Newsgroups: rec.autos.makers.honda; rec.autos.tech; rec.autos.misc
>>>Subject: Doing my own brakes (97 Accord) - need some advice
>>>Date: Friday, September 14, 2007 9:07 PM
>>>
>>>"*" > wrote in
>>>news:01c7f6ca$f811eee0$0c91c3d8@race:
>>>
>>>
>>>
>>>>Some anti-seize compounds, those intended for oxygen sensors for
>>>>example, contain glass beads. What sort of lubrication do you
>>>>suppose glass beads provide?
>>>
>>>
>>>First post doesn't seem to have "taken". Repost follows:
>>>
>>>The beads roll, to prevent seizure of the sensor?
>>>
>>>
>>
>>Don't confuse "seizing" with "galling."
>>
>>In this case we use the following descriptions......
>>
>>Threads "gall" in motion. Dry threads need lubrication to keep metal
>>from transfering from one side to the other.
>
>
>
>
> It has been my impression that galling was a phenomenon most commonly
> experienced between metals that were close in hardness. In other words, if
> one metal was significantly softer than the other, galling wouldn't occur
> for the reason that the softer metal would simply smear instead of balling
> up.
>
>

The most flagrant example of galling, (in my experience), was with large
stainless steel bolts/nuts in the semiconductor equipment mfg biz.

Since such assembly operations took place in clean room conditions, use
of grease, oil etc. was not an option. In fact, the only possibility wa
the use of IPA, (isopropanol), which worked to reach the required torque
spec...

JT

(No longer dons bunny suits)

Scott Dorsey wrote:
> Tegger > wrote:
>>> Some anti-seize compounds, those intended for oxygen sensors for
>>> example, contain glass beads. What sort of lubrication do you suppose
>>> glass beads provide?
>>
>> First post doesn't seem to have "taken". Repost follows:
>>
>> The beads roll, to prevent seizure of the sensor?
>
> Yes, it's sort of a kind of lubricant.
>
> Another example of that sort of macrolubrication is bentonite grease,
> which is made with a kind of clay that has big flat pieces that slide
> easily across one another.
>
>>> For drum brake shoe pads, there is "Brake Lube" - which is, simply,
>>> white lithium grease.
>> That's what I use in electrical connectors, which is what the factory used.
>> I did not know you could use it for where the shoes contact the backing
>> plate.
>
> I tend to suspect silicone dielectric grease is more effective on
> connectors,

it is - it's oem. bearing grease isn't a good insulator, is not good in
the wet and can deteriorate the plastic materials used in the connectors


> but the lithium grease is cheaper and should last twenty or
> thirty years.

it's not the grease that matters - it's the connectors!


> --scott
>