Green Brake Fluid???

I'm doing the 100 kmile service on 2002 Chevy Trailblazer 2WD with the 4.2L inline 6. The TB has ABS.

I'm working on the replacing and flushing the old brake fluid. This stuff has been in the TB since we purchase it in 2002. The old DOT3 brake fluid is GREEN. WTH??? Replacing with Valvoline Syn DOT3. I'm not concerned with compatibility, because Owner's Manual and warnings on the brake reservoir call DOT3.

In my 30+ years of DIY service, I've never seen GREEN brake fluid. Typically, it is a light clear amber color.

Did GM use some funky stuff once upon a time?
Is this a "normal" color?
Or do I have another problem on hand?

 

Moisture has got into the brake fluid discoloring it?

 

Haven’t noticed that in our 2006 Trailblazer.

Have noticed it eats fuel level sensors.

 

Crap.....thats another task...... Replace fuel filter.

I can do that when I replace tranny fluid and filter. Serp belt and pulleys too.

Then back on the Taco for Serp belt and tranny fluid/filter.

The TB is my daughter's car.

This Covid crap and employment situation has pushed me to be the family mechanic, landscaper, repairman.......any job we normally hire.......I learn to complete. Materials are less expensive than labor.

 

I believe green means that some funky algae is growing in it and deff needs to be completely fished out and replaced.

 

crap, double crap, crap squared.......

I did notice some "stuff" on the interior wall of the reservoir. I didn't think it was normal. Although, never suspected it to possibly be algae.

Well, fortunately, I ran out of brake fluid working 1 wheel (right rear). No solids were seen during the bleed, just green. Wasn't able to finish.

Ok. My thinking. Get a replacement Master Reservoir from Rockauto for about $20. Replace old resv with new, bleed/flush the system. I think I can remove the old resv without introducing air into the master cyl. I have a lube pump that can be used to empty most of the fluid. So, the mess should be manageable.

Will this plan work?????

Nothing like an 18 year old car.......

 

Well, I did a bunch of research.

The green is not likely to be algae. Algae needs sunlight to grow. It is a single cell plant.

The green is likely to be copper getting leached from the brazing of the brake lines.

Either way, the fluid needs to be flushed and the reservoir replaced. I'm going to push the TB onto the same maintenance schedule as the Tacoma. Since, I'm the one doing the work........

Thanks all for the direction. Looks like my simple flush has become a bit more difficult. Looks like I'll be ordering a reservoir and picking up 4 qts of DOT3.

 

Yes GM has had that for years. So much that copper test strips exist for brake fluid. It also somehow pits the abs pump motor and ruins it.

 

Whoever thought algae could be growing in hydraulic fluid needs some common with that sense.. i dont think algae can grow in any mechanical fluid.. washer fluid, antifreeze, oil, gas, refrigerant.. would be a big no way of anything growing in it. Only chemical reactions either breaking down the chemical into various hydrocarbons or structures from reactions of an external substance getting introduced into the mix.. aint gonna be any life forms or biology happening in there unless its been sitting somewhere for way too long and even then things would only possibly grow on the systems dry areas, inside or outside..