Brake Fluid Quantity

[M3@SG]

Did a search but was not able to find the info.

Any kind bros can advise on the quantity of the brake fluid required for the M3? I was told up to 1.5 litres for a change, but a workshop told me to have 2 to 3 litres for a full flush?

Kinda confused, i just wanna change the full amount of brake fluid, probably to motul. Dun understand the part about 'flushing".

Thanks for the education in advance.

[larryn]

I use two for a flush, but furthest point during a flush (passenger rear) starts seeing new fluid after .75 liter. I use a full liter to that corner, then another liter for the remainder of the three corners.

Luckily, I used ATE Blue to find this out before swapping to Motul RBF 660, which is the same color as factory fluid (maybe a bit more yellow).

[sawzall]

You shouldn't need more than 2 litres for a complete flush. You will probably use about a bottle and a half max.

[Small Yellow]

What? I've been using 1 liter to flush the whole thing... I have a 2010 e92 M3 if it makes any difference.

[M3@SG]

Hmm...i see differing views.

To clarify, I'm not talking about topping up or bleeding, but a full change of brake fluid.

The consensus appears to be less than 2 litres if you know what you are doing. I think i will buy 2.5 litres in that case, and use the excess for bleeding in the future.

Thanks!

[apecush]

I used under 1L of super blue to flush my car. The blue makes things pretty foolproof. Be sure to suck all old fluid out of your reservoir prior to bleeding or you will be using a lot more fluid than you really need to.

[FormulaMMM]

Originally Posted by apecush

Be sure to suck all old fluid out of your reservoir prior to bleeding or you will be using a lot more fluid than you really need to.

This is the key. Had a very successful flush (if I don't say so myself) last weekend. My 2nd time attempting.

First time I did not get any fluid out of the master cylinder beforehand. Sat at the back right for what seemed like 20 minutes waiting for all of the old to come through.. Also had quite a bit of leaking around the master cylinder cap (use the Motive Bleeder), and one of the joints that connects the two lines coming out of the bleeder. Not sure if related. All of the fluid in the cylinder creating back pressure perhaps?

Anyways, last weekend got all of the old fluid out of the master cylinder with a turkey baster first. Then 1 liter of fluid into the bleeder, had probably 1/4 liter remaining once I was done. No leaking whatsoever. Absolutely thorough flush -- went from the yellow ATE to the Super Blue. So >1 liter is not needed, but it's not a bad idea to have some extra on hand.