Brake fluid is black

[nbristow01]

Installed an all new brake system about 20 months ago. All seemed fine, fluid stayed clear. About 8 months ago I installed a new clutch master when I did my 5 speed swap. Also a new clutch slave. So a few months later the fluid is black. I flush, clean install new fluid. So fluid has turned black again. I believe the slave will usually leak when it is going bad. I have noticed I am gettnig a bit of erratic clutch pedal feel the last few days. Seems like the point of engagement, as far as pedal travel, is not consistant. Most the time it feels about like normal, good pedal travel, same release point. But I am getting this occassional change to where the pedal is mushy until just above the floor (when depressed)then try it again and it feels better.

Could the black I am seeing be from the clutch master seals etc getting erroded by the fluid? I just use plain old brake fluid that I grabbed off the shelf aty Oriellys.

thanks for any feedback. If I do have to grab another clutch master what fluid should I be running?

[Guest Anonymous]

are you flushing the clutch and brake systems completely and at the same time?

[Napes]

I, along with numerous ohers on this board, use Castrol GTLMA Brake Fluid. It's probably not much more expensive than "plain old brake fluid that I grabbed off the shelf aty Oriellys" and you will know you have a good product.

Bob Napier

[jgerock]

I, along with numerous ohers on this board, use Castrol GTLMA Brake Fluid. It's probably not much more expensive than "plain old brake fluid that I grabbed off the shelf aty Oriellys" and you will know you have a good product.

Bob Napier

I have to agree with Bob. Use good quality brake fluid and it should last a lot longer than the cheap stuff.

[Mike Self]

Suspect it's coming from deteriorating flex brake hoses and/or caliper/wheel cylinder seals...but more likely the hoses. Are they original or nearly so? If so, it's time to change 'em.

mike

[JohnS]

I guess this is one argument for not using Ate Super Blue brake fluid like c.d. suggested in another thread. The blue would make it harder to see the black...

[pkbinplano]

new SS brake hoses and ATE super Blue fluid , the clutch issue is air in line. been there.

[nbristow01]

new SS brake hoses and ATE super Blue fluid , the clutch issue is air in line. been there.

Hoses are new SS lines. I will flush and try what Bob said and see how it works out

[pkbinplano]

you may just need to flush your system more often as you drive a zillion miles a week >LOL

[Chris_B]

I had the hydraulic fluid in my 02 flushed recently because the fluid had become dark (not really black) over the period of about 18 months, but I had not really driven the car that much (maybe 1500 miles), and had not recently changed any components. A couple of years back, I installed stainless steel/teflon brake lines. Seems like the fluid turns dark over time from oxidization or the leaching of material from the lines/master or wheel cylinders into the fluid. Brake fluid seems to be pretty reactive stuff (don't get it on your paint...).

[Napes]

Just to clarify my comments about brand of brake fluid - I do not think that is the cause of the black fluid problem. I think some of the comments above address that. I was just saying that in the future you might want to go with a known quality product.

Bob Napier

[Guest Anonymous]

Could the black I am seeing be from the clutch master seals etc getting erroded by the fluid? I just use plain old brake fluid that I grabbed off the shelf aty Oriellys.

thanks for any feedback. If I do have to grab another clutch master what fluid should I be running?

Dark and contaminated fluid is common to all hydraulic braking systems that see a lot of use. Do you think rubber seals and lines (under tremendous pressure and heat) last indefinitely? Could be your etc, too.

Surprised you never encountered this phenomenon in your muscle car days.

[Guest Anonymous]

Plenty of information on this and other topics can be found in the archives;)

http://www.bmw2002faq.com/component/option,com_forum/Itemid,57/page,viewtopic/t,325052/

[JohnS]

I guess this is one argument for not using Ate Super Blue brake fluid like c.d. suggested in another thread. The blue would make it harder to see the black...

That was supposed to be a Joke. I've used the Ate blue and the Ate Typ 200 (gold) for years...

[TobyB]

The thing is, the clutch usually doesn't draw much off the reservoir-

the tube's so big and long (baby) that the reservoir is just

there for security.

And there's just not a lot of fluid circulation on a street- driven car.

Really.

Me, I'd suspect something odd with your rubber hoses, or the fluid...

or yeah, ok, maybe the master(s).

t