| Author |
Message |
Sheldon
Guest
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 Posted:
Sat Apr 16, 2005 11:46 pm Post subject:
Synthetic brake fluid? |
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My mechanic is hyping synthetic brake fluid. Apparently this is not DOT 5,
it's something else. Anybody know what he's talking about? He claims it's
great stuff.
Sheldon
sheldon@sopris.net
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y_p_w
Guest
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| Posted:
Sat Apr 23, 2005 5:45 am Post subject:
Re: Synthetic brake fluid? |
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Sheldon wrote:
| Quote: | My mechanic is hyping synthetic brake fluid. Apparently this is not
DOT 5, it's something else. Anybody know what he's talking about?
He claims it's great stuff.
|
Possibly low-hygroscopic DOT 5.1 or 4? I've seen some claims of
brake fluid that can go 5-10 years without replacement, but I'm
highly skeptical. There are some super exotic racing brake fluids
like Castrol SRF, which is about $70 for a 1 liter can.
BTW - nearly all modern brake fluids are "synthetic" save some
exotic systems requiring mineral oil based fluids. Using the term
"synthetic" to describe brake fluid is nothing more than a marketing
gimmick. Even rather ordinary Prestone DOT 3 is now being
marketed as "synthetic". |
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Sheldon
Guest
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| Posted:
Sat Apr 23, 2005 7:11 am Post subject:
Re: Synthetic brake fluid? |
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"y_p_w" <y_p_w@hotmail.com> wrote in message
news:1114217158.973407.317880@g14g2000cwa.googlegroups.com...
| Quote: | Sheldon wrote:
My mechanic is hyping synthetic brake fluid. Apparently this is not
DOT 5, it's something else. Anybody know what he's talking about?
He claims it's great stuff.
Possibly low-hygroscopic DOT 5.1 or 4? I've seen some claims of
brake fluid that can go 5-10 years without replacement, but I'm
highly skeptical. There are some super exotic racing brake fluids
like Castrol SRF, which is about $70 for a 1 liter can.
BTW - nearly all modern brake fluids are "synthetic" save some
exotic systems requiring mineral oil based fluids. Using the term
"synthetic" to describe brake fluid is nothing more than a marketing
gimmick. Even rather ordinary Prestone DOT 3 is now being
marketed as "synthetic".
|
Well, what I do know, after lots of research, is that you actually want your
brake fluid to absorb water. That's a good thing. So, if your brake fluid
is doing its job you need to replace it on a regular basis.
>
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y_p_w
Guest
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| Posted:
Sun Apr 24, 2005 12:21 am Post subject:
Re: Synthetic brake fluid? |
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Sheldon wrote:
| Quote: | "y_p_w" <y_p_w@hotmail.com> wrote in message
news:1114217158.973407.317880@g14g2000cwa.googlegroups.com...
Sheldon wrote:
My mechanic is hyping synthetic brake fluid. Apparently this is
not
DOT 5, it's something else. Anybody know what he's talking about?
He claims it's great stuff.
Possibly low-hygroscopic DOT 5.1 or 4? I've seen some claims of
brake fluid that can go 5-10 years without replacement, but I'm
highly skeptical. There are some super exotic racing brake fluids
like Castrol SRF, which is about $70 for a 1 liter can.
BTW - nearly all modern brake fluids are "synthetic" save some
exotic systems requiring mineral oil based fluids. Using the term
"synthetic" to describe brake fluid is nothing more than a
marketing
gimmick. Even rather ordinary Prestone DOT 3 is now being
marketed as "synthetic".
Well, what I do know, after lots of research, is that you actually
want your
brake fluid to absorb water. That's a good thing. So, if your brake
fluid
is doing its job you need to replace it on a regular basis.
|
It's two things really. You want it to absorb water that ends up in
the
system, so that there aren't small pockets of water that cause rapid
localized corrosion. Silicone doesn't mix with water and water that
ends up in the system ends up in the low points. Silicone doesn't
attract water though.
However - ordinary glycol-based brake fluids are hygroscopic, meaning
that they will absorb (actually attract) water vapor from air.
Different
brake fluid formulations are better or worse in that regard. I
remember
hearing about a demonstration where someone took a sealed bottle of
brake fluid in a humid climate at a racetrack near Atlanta. He then
poured the fluid into a shot glass up to the top. After an hour, the
fluid had spilled over simply because it attracted and absorbed
moisture
from the air.
Apparently ordinary brake fluids have a certain shelf life because a
small amount of moisture can permeate the plastics (or even the
plastic seals of metal cans). Once opened, brake fluid should be
used quickly - maybe less than two weeks to top off after a brake
job. No brak system is perfectly sealed, so moisture will be attracted
into the system by the fluid. |
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Sheldon
Guest
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| Posted:
Tue Apr 26, 2005 7:54 am Post subject:
Re: Synthetic brake fluid? |
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|
"y_p_w" <y_p_w@hotmail.com> wrote in message
news:1114284084.690614.37970@l41g2000cwc.googlegroups.com...
| Quote: |
Sheldon wrote:
"y_p_w" <y_p_w@hotmail.com> wrote in message
news:1114217158.973407.317880@g14g2000cwa.googlegroups.com...
Sheldon wrote:
My mechanic is hyping synthetic brake fluid. Apparently this is
not
DOT 5, it's something else. Anybody know what he's talking about?
He claims it's great stuff.
Possibly low-hygroscopic DOT 5.1 or 4? I've seen some claims of
brake fluid that can go 5-10 years without replacement, but I'm
highly skeptical. There are some super exotic racing brake fluids
like Castrol SRF, which is about $70 for a 1 liter can.
BTW - nearly all modern brake fluids are "synthetic" save some
exotic systems requiring mineral oil based fluids. Using the term
"synthetic" to describe brake fluid is nothing more than a
marketing
gimmick. Even rather ordinary Prestone DOT 3 is now being
marketed as "synthetic".
Well, what I do know, after lots of research, is that you actually
want your
brake fluid to absorb water. That's a good thing. So, if your brake
fluid
is doing its job you need to replace it on a regular basis.
It's two things really. You want it to absorb water that ends up in
the
system, so that there aren't small pockets of water that cause rapid
localized corrosion. Silicone doesn't mix with water and water that
ends up in the system ends up in the low points. Silicone doesn't
attract water though.
However - ordinary glycol-based brake fluids are hygroscopic, meaning
that they will absorb (actually attract) water vapor from air.
Different
brake fluid formulations are better or worse in that regard. I
remember
hearing about a demonstration where someone took a sealed bottle of
brake fluid in a humid climate at a racetrack near Atlanta. He then
poured the fluid into a shot glass up to the top. After an hour, the
fluid had spilled over simply because it attracted and absorbed
moisture
from the air.
Apparently ordinary brake fluids have a certain shelf life because a
small amount of moisture can permeate the plastics (or even the
plastic seals of metal cans). Once opened, brake fluid should be
used quickly - maybe less than two weeks to top off after a brake
job. No brak system is perfectly sealed, so moisture will be attracted
into the system by the fluid.
|
So, what would you put in your car? Synthetic or DOT 4? Why?
Thanks.
Sheldon
sheldon@sopris.net
> |
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y_p_w
Guest
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| Posted:
Tue Apr 26, 2005 9:25 pm Post subject:
Re: Synthetic brake fluid? |
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Sheldon wrote:
| Quote: | "y_p_w" <y_p_w@hotmail.com> wrote in message
news:1114284084.690614.37970@l41g2000cwc.googlegroups.com...
Apparently ordinary brake fluids have a certain shelf life because
a small amount of moisture can permeate the plastics (or even the
plastic seals of metal cans). Once opened, brake fluid should be
used quickly - maybe less than two weeks to top off after a brake
job. No brak system is perfectly sealed, so moisture will be
attracted into the system by the fluid.
So, what would you put in your car? Synthetic or DOT 4? Why?
|
I've used various DOT 4 brands, and had never been particular
about brands. I buy the fluid and take it to the shop. Among
the brands I've used are Prestone DOT 4, Castrol GT/LMA, Pyroil
DOT 4, and Valvoline SynPower. I just brought my car into the
shop today, and left 5 .25L cans of Motorex DOT 5.1 fluid for
the shop to install. I also have three bottles of Motul DOT
5.1 fluid that will probably be used at a later date.
Also - almost all normal brake fluids are "synthetic". DOT 3,
DOT 4, DOT 5, DOT 5.1. The only brake fluids that aren't would
be some exotic mineral (petroleum) oil based ones, used in some
Citroën or older British cars. |
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