Replaced the stock front and rear brakes on the wife's 2001 with drilled rotors and ceramic pads. I checked the fluid level each time I pushed a brake piston in so it wouldn't overflow and noticed the fluid looked green. I've seen yellowish and clear fluid but never green! What could this stuff be? I don't want to mix it with something else that might compromise the effectiveness of the fluid. Any thoughts?

 

Agreed, I have seen the amber fluid, and the older ATE superblue. Nothing green comes to mind for green brake fluid.

Only green fluid I can think of is the Pintosin CHS power steering fluid typically used for German cars, or maybe that convertible pump fluid (could be the same, I have a Coupe). Maybe take a bit of the green fluid out and try to mix it with water. If it does not mix (it's an oil of some kind), then go from there. Or if your car is a convertible, see if the fluid is the same as what is in the convertible pump tank in the trunk. Not good news if it is...

Best of luck, keep us posted.

 

ATE cannot supply blue fluid to the US now due to govt. regulations, so it's yellow. If you mix them it turns green, but it's not a problem. If the fluid mixes with water as suggested by fmertz that may be the answer.

 

Is may be different in the US but here in the UK, the only green brake and hydraulic fluid is Castrol HSMO (Hydraulic System Mineral Oil) or equivalent as used on XJ40 and 1980/90 Rolls and Bentley power brake, and hydraulic systems.

Graham

 

I had the same issue on my 2000 xk8. I think someone used the convertible top fluid in the brake system. I bled the brakes with the correct fluid super Dot 4 until the green was gone. No problems

 

As brake fluid ages from heat exposure the additives that balance the PH get depleted. Once the PH is out of range, any copper in the system is susceptible to corrosion. This is not a moisture problem its a PH problem. Where is the copper? On brazed steel tubing it's in the braze joint and coats the ID of the tubing. On copper nickel tubing... It's what the tubing is made of. The bad part is as the copper in the brake fluid is missing an electron. This is why you are seeing some flakes or particles. I know it was pretty common Audi's, as they had a lot of copper.


Short story... the green color is dissolved copper and an very strong indicator that your brake fluid is bad and may be damaging your brake system.

 

I think it's time to change the brake fluid. The manual says only use Jaguar Super Dot 4. I am nowhere near a Jag dealer. What else is suitable?

 

Any DOT 4 brake fluid. Pentosin Super DOT 4 is good, but don't get the LV (low volume) version.

I agree with the green being copper. Interesting fact, if, after firing porcelain for a tooth crown, the porcelain comes out green instead of white or a white-yellow shade, there is likely to have been copper contamination.

 

Pentosin Dot 4 LV (low viscosity) is what I used this past fall to flush my 2000 XKR brakes. Also used it in my BMW Z4 for brake flush. No ill effects and it worked well. I believe the LV designation is required for some applications in colder climates to ensure the ABS system works normally.

I live in southern Georgia and we've had temps around 100F last couple of weeks. Brakes worked just fine.

 

Since I have been working on British cars since the early 1970s I do remember the recommendation to use ONLY the old Girling “Green” or Lockheed "Crimson" brake fluid.
It was not available here in the US but the substitute was DOT approved Castrol GT LMA.

I still use it in my brothers 1952 MK VII.

The RR 363 seems to be the same Castrol fluid with a bit of 'bean-oil' in it?? (when it drips on the exhaust manifold you can DEFINITELY smell bean oil)

Thanks for the memories!!

bob