Gummy stuff in the master cylinder

[skipsor]

I just got home from having the brake fluid changed in our '04 Brave on the W20 chassis. It has just over 28k on the odometer, we bought it new. The brakes fluid was original.

The tech said he found a floating piece of black gummy, silicone type stuff floating at the top of the master cylinder. He described it as the size of a half dollar and about 1/4 inch thick. He removed it intact and placed it on a shop rag.

He tried to locate the rag he put it on to show me but he was unable to immediately find it . After a few minutes he found the rag but this stuff was no longer a semi solid. Instead it had melted into the rag and it left a sticky spot, a little larger than a half dollar on the rag.

He said he has seen a lot of stuff in brake cylinders over the years but nothing like this.

The question is, what was it and has anyone ever seen or heard of anything like this before?

[skipsor]

I just got home from having the brake fluid changed in our '04 Brave on the W20 chassis. It has just over 28k on the odometer, we bought it new. The brakes fluid was original.

The tech said he found a floating piece of black gummy, silicone type stuff floating at the top of the master cylinder. He described it as the size of a half dollar and about 1/4 inch thick. He removed it intact and placed it on a shop rag.

He tried to locate the rag he put it on to show me but he was unable to immediately find it . After a few minutes he found the rag but this stuff was no longer a semi solid. Instead it had melted into the rag and it left a sticky spot, a little larger than a half dollar on the rag.

He said he has seen a lot of stuff in brake cylinders over the years but nothing like this.

The question is, what was it and has anyone ever seen or heard of anything like this before?

[Don and Kim]

When I changed our brake fluid last year on our 03 W20 coach it has some "stringy" stuff that I sucked out with a syringe. I then wiped out the inside of the container. Not sure what it was either.

[DriVer]

The gummy stuff is perfectly normal - no need to remove it. What it is is a by product of the preservative and brake fluid mixing in the master cylinder.

The gummy stuff floats to the surface in the master cylinder and the clear brake fluid is directly below the skim coat.

Not to worry.

Now if the brake fluid itself is any other color other than DOT 3 there could be a broblem. Water in the brake fluid will turn it dark or black in color - time to flush the system.

[oemtech]

This is not an uncommon problem. Most tech don't get to excited over it.

Me, I see crap like that and its OUTA HERE. For about $12, a piece of plastic tubing and a empty 3 liter pop bottle you can gravity bleed your brakes in about 1 hr start to finish.

[skipsor]

DriVer, thanks for the explanation. Now I don't have to wonder if the brakes are going to gum up.

Other than the gummy stuff the brake fluid was clear.