How to change brake fluid.

hi,
Inspired by various discussions about brakes and clutches (hydraulic systems), I wondered how brake fluid is actually changed.
With or without the area for the clutch actuation?

I don't think anyone will do that!
Therefore, only very old Asbach brandy is being passed back and forth.
with the corresponding consequences!

or am I wrong?

best regards, leo

Okay, I'm doing the clutch brake fluid replacement. It takes about 5 minutes longer.
Otherwise, there are guides and/or user experiences available here.

Remove all tires, attach containers, connect the vacuum pump with the HL vessel, and continue filling until new BF (presumably referring to a fluid) appears, then add VR and HR to the VL (presumably referring to a liquid).

If you want to bleed the clutch (the fluid in the clutch system likely mixes very little with the brake fluid), there are several ways to do it. A simple method is to use the brake pedal and a connection between the brake caliper and the clutch bleed screw to push the fluid through. Alternatively, you can use a vacuum pump. Be careful to keep the fluid level in the reservoir high enough, as the clutch reservoir often has a small compartment at the back.

hi matthias,
I already understand that it should be done and how to do it.
However, there are some vehicle models where replacing the receiver-dryer is significantly more complicated.
like with my T4.
It will definitely take more than just 5 minutes.
And that's why it's often not done.

best regards, leo

Okay, generally speaking, many systems are structured in a very similar way.
If you're implying that workshops don't do it... well, read the workshop reports; it's not the only thing that's often overlooked.
I also believe that, in this particular case, adding a small amount of "Fusch" (likely referring to a non-specified substance) might not be the worst thing, as my opinion is that the thermal stress on the clutch master cylinder fluid is likely low, and therefore should rarely, if ever, reach a critical level. I only foresee a minimal dilution of the new brake fluid.

Hi!

I'm more concerned about the risk of rust forming inside the cylinders or a lot of dirt accumulating.
and this can cause them to leak.

But it doesn't seem to be that dramatic.
because the brake fluid in my old T3 has also been in there for at least 15 years.
Sure, no problem.

Well... if everything is working correctly, nothing will oxidize. And as for dirt? Well, there's no flow except when you're changing something.