Maximum brake fluid flush interval

[Rushfan1]

What is the maximum amount of time that should elapse prior to having a brake fluid change done? What is the impact of not regularly having your brake fluid flush? Incidentally my E21 is barely driven and spends 1/2 the year (winter) in the garage.

[Madhatter]

every 2 years is the usual interval.

Brake fluid is hygroscopic, so it absorbs moisture out of the air. The biggest problem with moisture is it lowers the boil point of the fluid, so its nowhere near as effective as before.

Replacement fluid helps keep systems clean and free of contaminants and stops seals from drying out or cracking. The impact of poor fluid is not having any brakes when go to use them, heh heh. Its up to you how long you want to wait for, but I was always taught that just because a vehicle isnt run/used a whole lot, doesnt mean it should be exempt from servicing. Oils still continue to break down even when the car is stationary, so if anything, to keep everything happy, a vehicle that sits around for a long time should still be serviced.

Personally, I just like to know things are going to be ok when you want to get in and drive it.