dannyual777

Okay, I've got hydraulic clutch problems and while looking at the clutch master cylinder, I noticed that my brake master cylinder appeared to have dark brake fluid in it. I removed the cap and the brake fluid is pretty much black .

I've owned the car since it was new and it has 25,000 miles on it. I'm going to bleed the brakes to get fresh, new brake fluid in the system. I was just wondering how often others are doing this.

BTW, I've been researching the bleeding process for these ABS/TCS cars and I found out that others have had the "black brake fluid" as well.

Duffster

iTrader: (103)

as often as you can see color in it (or in your case, tint. . .)

slow96ss

just replaced my rear end brake lines last week and my brake fluid was very black with debris in it before i pulled the lines off.

dannyual777

Like I said earlier, I've owned this WS6 since it was brand new. Not only is the brake fluid black but the clutch fluid is, too.

I've never owned another car that turned the brake fluid black. Last week, I bled the brakes on my 4-wheel Cobra disc braked Fox body Mustang. The fluid wasn't watery clear but it was an amber clear and I thought that was dirty. It certainly wasn't black like this TA's fluid is.

Mark2002

iTrader: (2)

I'm the original owner of my '02 Z28. 1st time I changed the brake fluid was early last year when it had 80K miles and it was black like you mentioned. Since then I've been to the road course track 4 times pushing the brakes much harder than any daily driving could do. My car is a full weight daily driver. I have flushed the system 1 other time since last year (changed calipers so had to). I'm running ATE Super Blue fluid and plan to flush it once a year since I also plan to track (road course) my car ~4 times a year... which reminds me... I'm about due

Mark.

leadfoot4

iTrader: (1)

I store my car for the winter ('96 Z-28), and one of the "rites of spring", every spring, is fresh brake fluid...

dannyual777

The car is up on jackstands for clutch hydraulics work and the brake fluid will be changed before the car comes down.

2QuikTA

How does one flush the system? Do you just continue to bleed until you bleed the old stuff out?

Chris_B

Brake fluid should be changed every two years at the most. It takes about that long for enough moisture to penetrate the rubber brake lines to lower the boiling point from the "dry" rating to the "wet" rating. Also, contaminants can get in, as you are experiencing.

leadfoot4

iTrader: (1)

The easiest way I found, so far, was to use a suction tool to draw the fluid through the lines. In all honesty, I found this suction device at the local marine supply store, but I know that other outfits re-label it, and sell it as their own product, often at ridiculous prices.

Basically, it's a 6-7 quart capacity plastic cylinder, about 18-20" tall, with a pump handle on top, as well as a connection for a suction hose at the top. You use the hose to initially pull the old fluid from the master cylinder, refill the master with fresh fluid, then starting at the RR wheel, hook the suction hose to the brake bleeder, use the pump to draw a vacuum in the hose, then crack open the bleeder screw and draw the old fluid from the line.

BMR Tech2

iTrader: (5)

I change mine several times a year because of track days but you're really supposed to change it once a year. Some will argue with that because they've never had a problem with their brake fluid after 4, 5, 6+ years. I'm just saying you're "supposed to" change it once a year. haha

leadfoot4

iTrader: (1)

I know what you mean. My wife has a very frugal (cheap) uncle who believes the same thing about engine oil. He drives about 22-2300 miles a year, mostly short hops of 1.5-2 miles, and honestly believes that it's OK to change the oil at 10,000 miles intervals, because A) it's synthetic oil, and B) somewhere in the owners manual, it says it's OK to go that long on oil...

DarkFox118

iTrader: (7)

a black brake fluid can mean the master cylinder is starting to break down as well.

I lost brakes one day becaoes of this. Even after doing new calipers pads rotors hoses and a flush my fluid was black within 1 drive.

a few days later.. I nearly rearended a lincoln and ran a 4 way stop.

fortunately, one of the two cylinders was still working.

Flush it if it's black and keep an eye on it. If it quickly turns black again.. you probably have what I had.

bayer-z28

iTrader: (14)

I never replace it but I bleed the brakes whenever they get spongy. I've had a couple cases where I boiled the fluid up front.... After a short time it was black again. Oddly enough, the fluid on my truck was never bled and it's the normal apple juice color.

Chris_B

One year IF you live in a very humid area. The stuff still technically works (stops the car) if in there longer, but the boiling point drops dramatically and the compressibility rises. This means that when you really need your brakes to perform, they won't have near the response they should have. Daily driving typically does not reveal what trouble awaits.

dannyual777

Now this has me concerned ! After flushing it, I'll keep a close eye on the brake fluid when the car is back on the road after I fix the clutch situation.

DarkFox118

iTrader: (7)

it's a cheap part. I got a raybestos replacement from rockauto.com.

yea, certainly keep an eye on it. My understanding is the rubber gaskets inside the piston.. thingy.. starts to break down and that can make the pedal go to the floor. If I did anything more than just barely ease on the brakes it'd go to the floor and I'd have no brakes. luckily mine failed on a saturday just about 15 miles from home.

if it turns black like immediatley after the flush I'd say go ahead and get new hoses and a master cylinder to be on the safe side. You need your brakes! I didn't listen to the mechanic that told me my master cylinder was goin bad. He told me over tyhe phone on how I described it.

he put the new one in. He didn't rub it in tho thankfully.

dannyual777

DarkFox, thanks for that detailed information. I'll keep a very close eye on that brake fluid and start replacing parts if the fluid quickly turns black again!

leadfoot4

iTrader: (1)

Which is very true, but since brake fluid is so cheap, why not change it on a regular basis??

dannyual777

Yesterday, my father-in-law and I bled the brakes to get fresh fluid in the system. The first thing that I did was suck out about half of the dark fluid from the master cylinder. I put the old fluid in a clear jar to inspect it. The color is an ugly, dark, dark green color. Not black but almost black.

I then refilled the master with fresh brake fluid and proceeded to bleed the brakes. Lots of dark green fluid came out and eventually I got relatively clear fluid to each caliper. I didn't bother to try to bleed the ABS block.

My brakes worked fine before and I'm sure that they're in much better shape now. Maybe in a year or so, I'll rebleed the system to get a better mix of fresh brake fluid in the system.