Brake fluid flush question .....

[mikado463]

So I'm going in next week for state insp and oil change and noticed that I also have an indication for brake fluid service and was told this is time not mileage related.

I've had my '17 X5 for two years and when I purchased it rotors/pads and fluid service work had been performed.

So, is the two year interval really that important ??

[blue dragon]

Why would you not do it? Brake fluid is hygroscopic and absorbs moisture. This will lead to a reduction in boiling point of the fliud. You next road trip that involves long hills with repeated brake use could result in a surprise lack of braking

[mikado463]

Originally Posted by blue dragon

Why would you not do it? Brake fluid is hygroscopic and absorbs moisture. This will lead to a reduction in boiling point of the fliud. You next road trip that involves long hills with repeated brake use could result in a surprise lack of braking

well for starters I've been driving since '69 and have never before on any vehicle changed brake fluid at a two year interval and have never had a brake fluid related issue. Regardless, I understand your point.......

[yupetc]

Relax, the brake fluid will be fine even if you don't change it. I've own several vehicles and going into teens years without changing a drop of it. Only filling it up did the trick. And out of 9 cars that I can count so far, only the E90 328i (it's a 2009) showed signs of sticky brake on the rear driver side. I took that caliper out, cleaned it, put it back in. Then flush the entire brake fluid. It's now mighty smooth again. I did also just flushed the brake fluid on my 2015 X5, and they are very dirty. But I couldn't tell a difference driving and braking. On the iDrive menu, I just keep resetting that service date every time it says due for service. The only thing I do screw around with are brake pads and oil changes.

BTW, since this year, I've then adopted using a new brake oil, it's the Motul 660, get it from Amazon. I stash a dozen of these in my garage for all my cars now. Been modding my cars lately, and with increase HP, I figured braking needs some upity bopity, too.

[Tomcat_F15_STL]

Originally Posted by mikado463

So, is the two year interval really that important ??

Best advice - don't take bad advice.

Flushing the fluid is important. It's all expensive when it goes to hell because simple maintenance was not completed.

Do it.

[mikado463]

Originally Posted by Tomcat_F15_STL

Best advice - don't take bad advice.

Flushing the fluid is important. It's all expensive when it goes to hell because simple maintenance was not completed.

Do it.

'TC', I tend to agree and given the fact that after two years my total maintenance expense as been but one oil change I shouldn't bitch , LOL !

With the vehicle being 5 years old and my plans to keep another two years I suspect the battery replacement will be the real big expense looking forward .....

[Djhumvee]

no, the 2 year interval isn't that important. 99% of every car on the road has the original brake fluid in it. That being said I plan on flushing out my old fluid in my 17' because it probably hasn't ever been done and I am replacing all of the calipers anyways. BMW says the tranny fluid is lifetime fluid so I hope everyone saying to follow BMW's advise never changes their tranny fluid lol.

[yupetc]

Originally Posted by Djhumvee

no, the 2 year interval isn't that important. 99% of every car on the road has the original brake fluid in it. That being said I plan on flushing out my old fluid in my 17' because it probably hasn't ever been done and I am replacing all of the calipers anyways. BMW says the tranny fluid is lifetime fluid so I hope everyone saying to follow BMW's advise never changes their tranny fluid lol.

LOL, pun taken, and agree, tranny fluid, on the other hand, should be changed regularly on every 60k-90k interval, or at least once every 100k miles.

[crystalworks]

I'll do brake fluid every 4 or 5 years normally, or when I pick up a used BMW to set a base line. Only reason to do it sooner is if you have to open up the system.

If you are occasionally tracking your X5, or towing regularly, ~2 years might make more sense just as a matter of safety.

[Clifton]

I'd strongly recommend fluid change every 2 years for a daily driver, and 3-4 year MAX limit for any car, including low mileage garage queens. A brake Fluid flush is an easy, one man job if you use a power bleeder. If you can pull a wheel off the car, you can do the job as well as punch another notch in your Man Card.

Click for Motive Pressure Bleeder

Yesterday, I performed a brake flush on a friend's 2016 Mini Cooper w/83K. No flush since his free BMW service ended after 4 years. His fluid looked like Mountain Dew you see in a bottle on the side of the road.

Basic procedures:

1. Use turkey baster to remove old fluid from reservoir, top off with new fluid
2. Fill power bleeder with a qt of brake fluid, attach adapter cap to reservoir, pressurize to 15 - 20psi
3. At caliper, crack bleeder screw with catch bottle attached to nipple, watch for new fluid
4. After ~8oz of fluid and light gold fluid, close nipple, move on to next wheel
5. Remove pressure bleeder, top off reservoir, replace cap - JOB DONE!

Bleed order - Pass Rear, Driver Rear, PF, DF
Fluid: ATE SL.6 or Type 200
Tools: 11mm wrench & Catch Bottle

[crystalworks]

^If you are doing your own brakes. A pressure bleeder is a must. I just bought one and used it for the first time after having to pull the master on our E70 to change the brake booster. Previous to that it was just using the 2 man pedal method, which sucks hard unless you have someone familiar with the process that you can trust to follow the timing.

Total game changer on the pressure bleeder. Especially if you are not opening the system and just flushing. If opening the system you will still need a tool capable of triggering the ABS pump multiple times. I went through 3 liters of fluid before getting it right.

But still, every 2 years is over-kill. Just another recommendation to get BMW dealers more money through the service dept. You can always test your brake fluid with a test strip to see if it has absorbed too much water and is in actual need of a flush.

[Tomcat_F15_STL]

I went through a lot of drama with a soft pedal after a master cylinder replacement.

Switching to DOT4-LV fluid & using a power bleeder sorted things out.

Also a bit of good advice, do not push fluid backward into the brake system by collapsing the caliper piston. Much better to crack the bleeder and then collapse the piston.

[Clifton]

Originally Posted by crystalworks

But still, every 2 years is over-kill. Just another recommendation to get BMW dealers more money through the service dept. You can always test your brake fluid with a test strip to see if it has absorbed too much water and is in actual need of a flush.

With all due respect, you can't test the fluid sitting in each of the pots behind the caliper pistons. The piston is a conduit that transfers heat from the pad to the fluid which can/will cook the fluid over time. Ultimately that's where moisture, air bubbles (converted from steam), and debris (from torn dust boots) can accumulate.

Also, as much I dislike paying for BMW service, I don't think this is a BMW money grab. BMW covers maintenance for the first 3 years/36K and could easily justify 3-4 year hydraulic intervals to avoid including that in the "free" maintenance program. Remember when BMW introduced the "Free" service and 3-5k oil changes intervals suddenly were stretched to 15K mile?

Is 2 years over-kill, I don't think so, but can I understand your perspective.
Can you go 4-5 years - absolutely. I bet some cars go lifetime without brake flushes. ATE, who makes brakes for BMW and many other European manufactures recommends less than 3 years flush intervals. Says so right on the can. Some of their fluids actually call for 1-2 yr service intervals as well.

At the end of the day, it's the OP's call. However, a Liter of quality brake fluid is $20 and who doesn't love a brake pedal that is consistent, responsive and can be modulated.

[mikado463]

Gents, thanks again for all the replies. Considering how little this vehicle has cost me in the 2 years of ownership (1 oil change) I'm just gonna go with the flush next Thursday when it goes in for state insp and oil change. Rotate the tires too while I'm at it !

[mikado463]

in and out in a little over two hours today, state insp, oil service, brake flush, tire rotation, wash and a vacuum, all for less than $400

[Clifton]

I’d say you made out ok overall. The one thing I dislike about brake fluid flushes and oil changes is disposing the used fluid. Auto parts stores have drums for used oil, but I’m not certain about brake fluid.

Also, I flushed my ‘17 X5 this week. Amazingly simple and I didn’t even have to take the wheels off. The rear bleeder valves are actually horizontal making them even easier to access.

The other fun fact I learned is that the F15’s use DOT 4 Class 6 fluid which has a low viscosity rating to support quick response times required of newer ABS and ESP/TC systems. The other interesting fact is that Class 6 have a short service life of 1-2 years.

I think this helps to further explain BMW’s recommended and seemingly short 2 year service intervals.