Brake hydraulic replacement

After the problem I had recently, the brake center was changed and the missing hydraulic was completed. I just came across a piece of information. When different types of hydraulic oils such as old and new mix, they lose their effect.
I want to completely drain the brake fluid and replace it with dot4.
After all, the problem that I had fresh didn't come to joke. How can I completely drain the brake fluid?

You will pour the new hydraulics from the top oil cap and remove the records from each of the wheels in order.

But I think there is no need, if the previous oil is dot4, there will be no problem.

There is no problem with the pedal and no problem with its stance. In both of them, the dot 4 added a master open hydraulic oil after the brake Center replacement. I said it was Dot4. I don't know, no problem

[QUOTE = OguzhanKucuk61] There is no problem with the pedal and no problem with its stance. In both of them, the dot 4 added a master open hydraulic oil after the brake Center replacement. I said it was Dot4. I don't know, don't worry [/ QUOTE]

[QUOTE = x571] [QUOTE = OguzhanKucuk61] There is no problem with the pedal and no problem with its stance. In both of them, the dot 4 added a master open hydraulic oil after the brake Center replacement. I said it was Dot4. I don't know, don't worry [/ QUOTE]
[/ QUOTE]

When the customer becomes an intermediary, they do it carefully if it is their own intermediary. I will look at the channel, thank you