Nessecary Brake Fluid Flush?

[Bradley Walker]

Hey all,

I noticed on the 90k service leaflet given out by the local dealership, that
it says a brake fluid flush every 30k miles is required. Is this true or
false? I checked my resovoirs and the fluid is a light amber color with no
dirty chunks, no signs of water in the lines, and the brakes are working
fine. I take it this isn't needed??

Advice, thoughts, opinions?

Brad

 

[mulder]

Hey all,

I noticed on the 90k service leaflet given out by the local dealership, that
it says a brake fluid flush every 30k miles is required. Is this true or
false? I checked my resovoirs and the fluid is a light amber color with no
dirty chunks, no signs of water in the lines, and the brakes are working
fine. I take it this isn't needed??

Advice, thoughts, opinions?

Brad

Yes it's a good idea. You can't tell by looking if there is water in
the lines, and brake fluid is by nature hygroscopic so chances are
that the fluid has in fact absorbed some water over time. At the
outside a flush should be done every 30K or two years.

 

[SilverStude]

Hey all,

I noticed on the 90k service leaflet given out by the local dealership, that
it says a brake fluid flush every 30k miles is required. Is this true or
false? I checked my resovoirs and the fluid is a light amber color with no
dirty chunks, no signs of water in the lines, and the brakes are working
fine. I take it this isn't needed??

Advice, thoughts, opinions?

Brad

No signs of water in the lines? How did you check this out? If you
actually opened a bleeder screw, then you should have gone the entire
route and flushed the fluid. It's not that difficult and one of the
things that you can still do yourself. Your ABS system may be another
thing to deal with though. Some are integral with the brake system,
some are not. It's always a good idea to flush Dot3/Dot4 fluid every 2
-3 years.

 

[Edward Hayes]

The ugly BF is in the calipers so the reservoir usually always looks
good. I flush every 3 years and am amazed at the difference in
braking. Brake fluid absorbs water and some moisture does get in as
the caliper cup slid back and forth during braking. The moist air in
the system reduces the effectiveness of the system because air
compresses and BF does not. Just do it and drive happy.

 

[Wvd]

only needed if you drive in the hills/mountains where the brakes (and the
fluid !) may become very hot during downhilling.

I live in the Netherlands and never made a brake fluid flush, only when I
replaced the (front) brake discs after 150.000 miles (Subaru Legacy)

Wilco

 

[mulder]

Well you've been fortunate if you haven't had brake issues.
The official Subaru of America maintenance schedule, which can be seen
on the SOA website here-
http://www.subaru.com/owners/schedules/index.jsp
calls for a brake fluid flush every 30K.

 

[Rick Courtright]

it says a brake fluid flush every 30k miles is required. Is this true

Hi,

I don't know if mileage is that critical, but every two years is a good
interval to flush brake systems. All the reasons have been given.

And, yes, there are people who never flush their systems. I've gotten a
hold of some of their cars in the past. Ever hear the saying, "Penny
wise and pound foolish?" It applies here.

Rick

 

[Bradley Walker]

Thanks, I'll let the dealership go ahead and flush the brake fluid then. I
was told by someone that if the fluid wasn't nasty brown or showed problems
of corroded lines, leaks, etc that there was no need to flush it.

 

[nrs2001]

Why don't they use a fluid that does not attract water. Like
sillypuddy?

 

[Jim Stewart]

Why don't they use a fluid that does not attract water. Like
sillypuddy?

Because water freezes. You'd not want
a blob of ice blocking your brake line
would you?

 

[BoB]

Thanks, I'll let the dealership go ahead and flush the brake fluid then. I
I don't see my msg on this subject so will send again.

My dealer claims they test the brake fluid to determine the need for
a flush. If the test is ok, they do nothing. My '02 Forester tested
OK at 30k.

Ever hear of such a test? Would this be factory authorized?

TIA,

BoB

 

[G.J.H. Jørgensen]

Hi Wilco,

In a posting in this group last month I dealt with the same problem, but I
take quite a different view on it.
I live in The Netherlands as well, we have a wet climate, temperatures vary
greatly, and traffic is dense (a lot of braking is required).
Brake fluid is highly hygroscopic, it attracts water as well as dirt through
the seals.
Moreover, it ages (due to intense heating/cooling) relatively quickly.
I know what a jamming brake does to your car at highway speeds (experienced
it 30 years ago on an Autobahn in Germany).
Cause: rusted pistons and cylinders in the rear drum brakes (Renault, not
Subaru).
The car (Renault 12TS) was 2 years old, had only run 30,000 KM.
Since then I have the brake fluid replaced every 2 years, the same holds
good for power steering fluid and coolant.
All these (especially the hydraulic) fluids are subject to ageing and
deteriorating.
It's a 'small' investment in durability and safety - I know!
The fact that Subaru advise to change them every 2 or 3 years (model, age)
is sensible, I think even obligatory!

Georg

 

[JohnO]

It's not that difficult and one of the
things that you can still do yourself. Your ABS system may be another
thing to deal with though.

Is there anything unusual about flushing BF in a 99 Outback? Or are
they the same as regular cars? ...I can look up specific details later,
I'm just wondering if my car has a special procedure.

-John O

 

[Jim Stewart]

Is there anything unusual about flushing BF in a 99 Outback? Or are
they the same as regular cars? ...I can look up specific details later,
I'm just wondering if my car has a special procedure.

The only odd thing I can remember is that
the front and back bleeder valves take
different sized wrenches.

 

[Rick Courtright]

Ever hear of such a test? Would this be factory authorized?

Hi,

While I've never heard of such a test, at least at a fairly "low user"
level such as a dealer or mechanic, it doesn't mean there isn't such a
thing--I's sure the mfrs have many tests available! Personally, I'd file
"testing" brake fluid at 30k miles when the book says "change it" in the
same league as "oil analysis" at 5k miles when the book says "change
it": you can pay for the test which will possibly tell you "change now"
or just go ahead and change the fluid for probably about the same amount
of money and KNOW what's in there is ok.

The guys who write the service recommendations generally don't pull
these numbers out of a hat, contrary to what all the "barstool experts"
would have us believe!

Rick

 

[Edward Hayes]

With all the time spent on the computer discussing this the Suby owner
could have flushed 10x vehicles. The manual recommends it and most of
us with some experience recommend it. Trying to second guess the
factory often ends up being a big mistake. Your brakes can feel great
in day to day driving but, one hard panic stop and you will be glad
you flushed your braking system. THE END.

 

[Jim Stewart]

BoB wrote:




Hi,

While I've never heard of such a test, at least at a fairly "low user"
level such as a dealer or mechanic, it doesn't mean there isn't such a
thing--I's sure the mfrs have many tests available! Personally, I'd file
"testing" brake fluid at 30k miles when the book says "change it" in the
same league as "oil analysis" at 5k miles when the book says "change
it": you can pay for the test which will possibly tell you "change now"
or just go ahead and change the fluid for probably about the same amount
of money and KNOW what's in there is ok.

The guys who write the service recommendations generally don't pull
these numbers out of a hat, contrary to what all the "barstool experts"
would have us believe!

You'd really want to know what the fluid
in the caliper is like, not just a sample
out of the master cylinder.

 

[BoB]

Hi,

While I've never heard of such a test, at least at a fairly "low user"
level such as a dealer or mechanic, it doesn't mean there isn't such a
thing--I's sure the mfrs have many tests available! Personally, I'd file
"testing" brake fluid at 30k miles when the book says "change it" in the
same league as "oil analysis" at 5k miles when the book says "change
it": you can pay for the test which will possibly tell you "change now"
or just go ahead and change the fluid for probably about the same amount
of money and KNOW what's in there is ok.

The guys who write the service recommendations generally don't pull
these numbers out of a hat, contrary to what all the "barstool experts"
would have us believe!

Rick

Thanks Rick and Jim,

I'll delve into it more at the next oil change. Strange nobody's
heard of this test.

There is no charge for the tests. They said they were trying to
not run up the 30k costs, but I have to confirm just how effective
and 'approved' their test is. The charge to change the fluid is
of no consequence to me. I've paid cash for all three of my Subies.

Thanks again,

BoB

 

[B A R R Y]

I'll delve into it more at the next oil change. Strange nobody's
heard of this test.

I'd like to hear details of the test, as well.

I'm surprised (and refreshed) a shop suggested a customer NOT do work.
Since the service isn't included in anything you were already paying
for, and they would be able to bill you more by flushing the brakes,
I'd probably trust them.

Most shops would gladly do useless but requested services, like draining
and refilling your tire air, if you are willing to pay the shop hourly
rate. <G>

While I know manufacturers don't pull service intervals out of their
ass, I do believe there is at least SOME CYA that goes on. Since many
people won't flush the brake lines every 30k, this recommendation gets a
manufacturer off the hook for lots of problems that may not have been
prevented by the flush anyway.

 

[B A R R Y]

I'd like to hear details of the test, as well.

Lo and behold! Google is my friend!

This page:
<http://www.aa1car.com/library/bfluid.htm>
contains a wealth of information aimed right at our topic.

At least TWO testing methods that can be done right in the shop are
mentioned, test strips and an electronic device.

Maybe someone's found a reputable shop? <G>