Brake Fluid Type

[rglassma]

My wife picked up Prestone DOT 4 synthetic brake fluid. Will this work for topping off the rear res?

[hp1bmw]

BMW does not reccomend any synthetic brake fluid. The rubber they use to make their hoses is not compatiable with synthetics.

Jim

[Dman]

Jim,
Are you sure that you don't mean silicone based fluid? (Dot 5.) as not being compatible?

Synthetic fluids classed as Dot 4 should be just fine and will more than likely say on the container that they are compatible with all Dot 4 fluids.

Good Luck

[mwnahas]

My wife picked up Prestone DOT 4 synthetic brake fluid. Will this work for topping off the rear res?

The good...Dot 4 is spec and what you want, don't know about prestone I bought the BMW stuff. :)

The Bad...Do not mix Dot 4 and Dot 5

[dshealey]

My wife picked up Prestone DOT 4 synthetic brake fluid. Will this work for topping off the rear res?

Yep, DOT 4 is correct.

Do NOT use DOT 5! That is Silicone, and cannot be mixed with non silicone.

Most brake fluids these days are synthetic though.

[rglassma]

Thanks Guys,

That is what I thought. But, whenever I am in doubt, I check here. It is definately dot 4 and it does say compatible with dot3 and dot4.. So, I guess we are good to go. Will just be using it to top off the rear since that pesky light keeps going on in cold early morning weather..

Regards..