Yes and no. Yes you can "top up" as it says on the can "compatible with Conventional Brake Fluids", however, how long since you have flushed the system. Should be once a year. Yes your brakes will work just fine, but wouldn't you feel better with clean fresh fluid in the system?


If your brake fluid is, as you say, "close to minimum", I would check your brake pads. Most likely you need to replace them. I NEVER "top up" the brake reservoir, when you go to change the pads and push back the caliper pistons, the reservoir will spill over making a paint removing mess!

This weekend I am changing the pads and flushing the brake system on my G. I am using EBC "Green Stuff" pads and Valvoline SynPower Brake Fluid. The next weekend I am going on the Raging Bull Texas Stampede, the fastest, funnest, road rally in Texas. 350 miles of the twistiest roads in Texas. I'll let you know how it goes when I get back. I had no problems with the factory brakes last year. I now have over 41K on them and they still have a lot of wear left.

BTW, this from the Valvoline website:

 

Brake pads are fine. I only got the car in April, and it had just over 30k km on it, and from japan. Got told it was properly services, and knowing japanese, they do everything proper. So I'm thinking of flushing it with the next service ill do in about 6 months.

Thanks for the advice!

 

The brake pad acts as an insulator as the pad wears the caliper piston gets closer to the hot rotor and thus the brake fluid gets hotter. The mass of the pad decreases [metal backing plate doesn't change] to near nothing. Thus the reason for 2-3 mm MINIMUM pad thickness is to reduce the chance odf fluid boiling.

Worn pads will boil fluid faster than brand new pads.

Why I replace my pads way before the minimum is reached.

Fluid type, age, moisture, and pad thickness are the ways you control fluid temperature and fade.

You can skin the cat in multiple ways.

One must cost analyse the cost of flushes and fluid compared to new brake pads and pick a safe suitable interval for each.

You have pads that fade at 600-800F and fluid that fade boils at 400-250F which is more likely to happen in your case?

Easy to mount a thermocouple between the backing plate and piston to see whats happening on your individual car.

 

Don't assume shops [in general] know anything about Brake fluid especially chemistry.
They push whatever is profitable.

Members can spend 15-40 hours of research [primarily on web] and learn much more than almost any shop technican in US.

Specialty brake [stoptech, etc] companies may have research chemist or consultants and have a good understanding of the situation.