itsav8

I suppose your rite.... Austin told me not to argue with him... waste of time ;-)

Katman

Same thnig.. Whenever underhood temps went up, brakes would drag, and the pedal would feel weird.

(I'm not sure how underhood temps would make me need to look at the 4 corner calipers first? And if at teh corners, how the problem would go away once I got back on the highway..)

Anyway.. "Bench Bleed" the master first, and you may not have to even bleed any further. I didn't, so replacing the master cylinder was easy.

Bench bleeding is where you have the master off the car (say, mounted in a vise). You attach the fluid resevoir, and put some tubes in the outlet ports, pointing back into the resevoir (Came with my master cylinder).

Aslo, you shodl not operate the master without any fluid in it, as there is possiblility of damaging the seals (without any brake fluid to lubricate)

Fill up the resevoir, and operate the cylinder. Air and fluid will come out the tubes, and dump back in the resevoir. Keep cycling until no mor bubbles. Then (keeping air out of the master), install it on the car. As the master is now already charged wit fluid (if you are careful) not much further bleeding required.<ul><li><a href="http://www.tegger.com/hondafaq/mastercylinderreplace/benchbleeding.html">Read this for more on how to bench bleed the master</a></li></ul>

cuatrokoop

HAHAHAHAHA!!!!

cuatrokoop

for contamination, with no filtration...

shortyq

But also find any roils between Ron and Bernie is a bit of an oxymoronic rush....

Back to the OP: Me, I'd flush that fluid out, and use a pressure bleeder to do so. Then I would make sure all the caliper pins are sliding correctly in the carriers. Then I would replace the 18 year old rubber lines. When that fluid starts getting "particles" in it, that's usually paint chips, and they can clog the lines quite easily.

WRT the post about not changing fluid, a sealed system doesn't mean a thing, temp changes of brakes heated to 500 degrees then back to ambient will cause moisture in the system. Brake fluid being hydroscopic by definition means that this property of absorption is increased significantly. Read: 2 years on brake fluid max.

Enjoying the reads

Scott J
Surfin the tsunamis
92 v8 4.2 ABT chip
2.5 Urq's
2.0 CGT's

Mister Bally

Just curious, why doesn't GM, Ford or Chrysler require brake fluid replacement periodically?

Crayzkirk

From what I've seen, all major US auto makers recommend flushing of all fluids every 24000 miles or two years.

I believe that people simply drive faster and harder than ever. We also keep cars longer than before.

Higher temps, more abuse, ect.

Kirk S.

shortyq

GM says lifetime in their brake presentation symposium, and says to use the FASCAR strip test. Fascar measures copper inhibitors (corrosion) in the brake fluid as a 'bad' test. Go to FASCAR site, their Chemical Engineer claims after 34000miles the inhibitors are basically gone. 34k normal driving = 2 years?

Since the brake fluid tests of 'moisture' really aren't reliable, there is no real test for interval. IMU, this also assumes that brakes are never above their boiling point and that severe duty has no affect on brake fluid life.

Me, I think this is all speculation and marketing, even the FASCAR strips speak to 'selling' brake fluid changes based on corrosion inhibitors, not service interval or moisture content. Regardless, it would appear even GM's reference to FASCAR indicates that a claim of "lifetime" brake fluid is just not supported.

What's more concerning in Audis specifically, is that the fluid will eat the paint in the master cylinder and particulate matter can be found in brake fluid, btst.

My own thinking is that anyone that beleives brake fluid interval changes are not a routine service, needs to find a reference. Car companies saying that fluid is lifetime, sounds like Audi claiming Auto trans fluid is lifetime too.

Cheers and my .02

Scott J