[PresidentEvil]

I used these brake fluid / coolant fluid test stripes

link here

one of the reviews said something about the brake fluid test not being accurate because the brake fluid doesn't circulate so the brake fluid at the calipers will be in worse condition and have more moisture than the fluid in the reservoir

I did the test and both tests said my fluids were very good, its a 2018 M2 but I don't know if the coolant or brake fluid was ever changed as I only bought the car 9 months ago

anyone have any experience with this?

[edycol]

Originally Posted by PresidentEvil

I used these brake fluid / coolant fluid test stripes

link here

one of the reviews said something about the brake fluid test not being accurate because the brake fluid doesn't circulate so the brake fluid at the calipers will be in worse condition and have more moisture than the fluid in the reservoir

I did the test and both tests said my fluids were very good, its a 2018 M2 but I don't know if the coolant or brake fluid was ever changed as I only bought the car 9 months ago

anyone have any experience with this?

Change it.
Factory fill: after 3 years.
After that every two if not tracking.

[Maynard]

The issue is water contamination - that dissolves in the fluid, so lack of circulation doesn't affect it (evenly distributed). Sludge and contaminants settle to low spots, but no reason to expect those in a newer car that hasn't been opened up or had brake work.

[edycol]

Originally Posted by Maynard

The issue is water contamination - that dissolves in the fluid, so lack of circulation doesn't affect it (evenly distributed). Sludge and contaminants settle to low spots, but no reason to expect those in a newer car that hasn't been opened up or had brake work.

Flyid itself is hygroscopic. Moisture will find its way to fluid through microscopic pathways in rubber lines. Opening reservoir or nit does not have anything with it.

[Maynard]

Originally Posted by edycol

Flyid itself is hygroscopic. Moisture will find its way to fluid through microscopic pathways in rubber lines. Opening reservoir or nit does not have anything with it.

Agreed, the water is constantly seeping in and dissolving equally into all the fluid in the system. But what I meant was that in a newer car you would not have the sludge present that WOULD localize to lower spaces or near to where it entered (calipers, wheel lines, etc); that type of contaminant is the only thing that would not be expected to show up in the reservoir for easy test identification. On tracked cars it is also common for the fluid near and inside the caliper to be heat-damaged and darkened moreso than what is up in the reservoir.

[edycol]

Originally Posted by Maynard

Agreed, the water is constantly seeping in and dissolving equally into all the fluid in the system. But what I meant was that in a newer car you would not have the sludge present that WOULD localize to lower spaces or near to where it entered (calipers, wheel lines, etc); that type of contaminant is the only thing that would not be expected to show up in the reservoir for easy test identification. On tracked cars it is also common for the fluid near and inside the caliper to be heat-damaged and darkened moreso than what is up in the reservoir.

Well, to prevent that one has to change fluid regularly. In Europe they test fluid for each technical inspection for registration.
Track fluid needs to be changed often. I change it 2-3 times during track season. But, we are talking fluid. Pressure changes will mix fluid. Also, fluid is on the move as pads are worn out.