[djwoodyuk]

Hi.
I am looking to change my brake fluid shortly.
Which would you recommend?
I have been looking at Pentosin DOT4 LV. Seems good value.
I am not tracking the car, so just need it for fast road.
Also, it is just 1 litre I need?

F30 335d with 370mm Fronts

[Billfitz]

BMW fluid is no more expensive than most.
Before changing mine I got one of these, to be sure that it actually needed changing:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

It showed the water content of my brake fluid at 0%, saving me the bother of changing it when it wasn't due.

[sspade]

Originally Posted by Billfitz

BMW fluid is no more expensive than most.
Before changing mine I got one of these, to be sure that it actually needed changing:
https://www.amazon.com/gp/product/B0...UTF8&psc=1

It showed the water content of my brake fluid at 0%, saving me the bother of changing it when it wasn't due.

Wow, cool gadget. May have to pick one up. Anyone know what the recommended interval for changing fluid? I seem to remember it being really long, like 100k miles but I could be wrong...

[bheng89]

the recommended interval is every 2 years.

I plan to use ATF super blue (or the US variant super gold) when I do it.

[Billfitz]

It's two years or 20k miles, but there's nothing scientific about that interval, they just figure it's better to change the fluid before it gets water in it rather than later. I'm at 3 years but only 12k miles, so I wanted to be sure it was broken before I fixed it, what with the purging and bleeding procedure being the PITA that it is.

[_bdiddyb_]

Originally Posted by Billfitz

BMW fluid is no more expensive than most.
Before changing mine I got one of these, to be sure that it actually needed changing:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

It showed the water content of my brake fluid at 0%, saving me the bother of changing it when it wasn't due.

Bill, instruction said to dip into reservoir to check. But brake fluid doesn't circulate back up to the reservoir. Don't you need to bleed some out from any caliper to get a better measurement? Cool gadget though.

[rak299]

I would expect water content to be highest at the reservoir. At the caliper or in the lines, how would water get in?

[Billfitz]

Originally Posted by rak299

I would expect water content to be highest at the reservoir. At the caliper or in the lines, how would water get in?

+1, the main source of contamination would be water vapor that gets past the reservoir cap. For water to get in further down the line there'd have to be a leak. The directions with the tool say that 2% water content is OK, but I wouldn't wait for it to hit 3% before changing it.

[Polo08816]

Castrol SRF hands down. Change out 1x per season since it has such a high wet boiling point.

[sspade]

Originally Posted by Billfitz

It's two years or 20k miles, but there's nothing scientific about that interval, they just figure it's better to change the fluid before it gets water in it rather than later. I'm at 3 years but only 12k miles, so I wanted to be sure it was broken before I fixed it, what with the purging and bleeding procedure being the PITA that it is.

If its every 20k, why arent dealers performing this under the 50k maintenance warranty?

Has anyones dealer performed this service for free under warranty?

[Billfitz]

They should, it is a CBS item, just like oil and so forth. I got the dashboard notice that it was due, but didn't take it to the dealer, as that's a 3 hour round trip, plus the time spent waiting. I'd have changed it myself if it turned out that it did need it, and will when that time comes.

[ibn_adam]

CBS!

[MacklinUSOB]

I use RBF600 and flush once a year. Thinking about trying SRF as I've heard good things, but have yet to boil the RBF. I do a bleed after every couple track days to keep the pedal nice and taught.

[bimmer456]

Got my brake fluid done for free as part of free maintenance. Had to pay for new tires though.

[EstorilMSport]

@MacklinOSB how much fluid is required for a full system flush? I’m looking to replace my OEM fluid (about 6 months old) with RBF600 to prep for an HPDE event.

[jh_f30]

Originally Posted by EstorilMSport

@MacklinOSB how much fluid is required for a full system flush? I’m looking to replace my OEM fluid (about 6 months old) with RBF600 to prep for an HPDE event.

I just did mine with ATE Type 200. 2 liters should be more than enough.

[MacklinUSOB]

Originally Posted by EstorilMSport

@MacklinOSB how much fluid is required for a full system flush? I'm looking to replace my OEM fluid (about 6 months old) with RBF600 to prep for an HPDE event.

As Jh said, about 2 liters/quarts should do the job. I would buy three quarts just in case you over bleed somewhere, worst case scenario you've got an extra bottle when you want to bleed them next. Make sure you do not let the power bleeder go dry (assuming that's what you're using).

[Polo08816]

Originally Posted by Polo08816

Castrol SRF hands down. Change out 1x per season since it has such a high wet boiling point.

Originally Posted by MacklinUSOB

I use RBF600 and flush once a year. Thinking about trying SRF as I've heard good things, but have yet to boil the RBF. I do a bleed after every couple track days to keep the pedal nice and taught.

I've been re-thinking this. I used Castrol SRF when I did not have a garage and space to easily put the car onto jack stands. The premium was well worth the time savings to drive 45-60 mins to an Auto Skills Center, spend 1-2 hours to bleed, and drive another 45-60 mins back home.

However, it should be noted that the wet and dry boiling points of RBF600 are only slightly above ATE Type 200. RBF is almost 3x the cost of ATE Type 200. This means that you'll have to bleed RBF600 almost as frequently as ATE Type 200. Even then, the dry boiling point of ATE Type 200 is still higher than the wet boiling point of Castrol SRF.

In conclusion, I think only 2 routes that really make sense are to either bleed frequently (before every other event) with ATE Type 200 or bleed 1-2 times per year with Castrol SRF.

Originally Posted by MacklinUSOB

As Jh said, about 2 liters/quarts should do the job. I would buy three quarts just in case you over bleed somewhere, worst case scenario you've got an extra bottle when you want to bleed them next. Make sure you do not let the power bleeder go dry (assuming that's what you're using).

2 quarts is more than sufficient to do the job. You could do both a standard and DSC bleed with that amount of brake fluid.

[bavarianride]

Originally Posted by sspade

If its every 20k, why arent dealers performing this under the 50k maintenance warranty?

Has anyones dealer performed this service for free under warranty?

My 2013 F30 had two brake fluid change under 4 years/50000 miles of free maintenance.

At year 6 mark, both brake fluid and coolant were changed@dealer for $250 with BMWNA coupon.

[FaRKle!]

Originally Posted by jh_f30

I just did mine with ATE Type 200. 2 liters should be more than enough.

Originally Posted by MacklinUSOB

As Jh said, about 2 liters/quarts should do the job. I would buy three quarts just in case you over bleed somewhere, worst case scenario you've got an extra bottle when you want to bleed them next.

Originally Posted by Polo08816

2 quarts is more than sufficient to do the job. You could do both a standard and DSC bleed with that amount of brake fluid.

2L/qts is WAYYYY more than you need. 1L is plenty to change out the whole system (I've done it, and still had some leftover). I disagree with buying 3 quarts (especially if you're getting the expensive stuff like SRF). Also, if you're planning on "using the leftovers later" I'd try to put the brake fluid bottle that you opened in a hermetically sealed container/bag to prevent moisture intrusion.

[MacklinUSOB]

Originally Posted by FaRKle!

2L/qts is WAYYYY more than you need. 1L is plenty to change out the whole system (I've done it, and still had some leftover). I disagree with buying 3 quarts (especially if you're getting the expensive stuff like SRF). Also, if you're planning on "using the leftovers later" I'd try to put the brake fluid bottle that you opened in a hermetically sealed container/bag to prevent moisture intrusion.

Using opened containers is not something I suggested. If it's opened and there is some left, toss it.

Having an unopened bottle of brake fluid is a good thing to have, every person I know who goes to a track has one just in case. If you are bleeding for the first time it is easy to overbleed. If that happens and you have no extra, good luck driving to the store for more.

[Polo08816]

Originally Posted by MacklinUSOB

Using opened containers is not something I suggested. If it's opened and there is some left, toss it.

Having an unopened bottle of brake fluid is a good thing to have, every person I know who goes to a track has one just in case. If you are bleeding for the first time it is easy to overbleed. If that happens and you have no extra, good luck driving to the store for more.

That's what the parking brake is for. Who uses the foot brake anyways? That shit is for pussies. Wide open throttle and ripping the parking brake for the most epic drifts is the only way to drive.