F30POST
F30POST
2012-2015 BMW 3-Series and 4-Series Forum
BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read
BMW 3-Series and 4-Series Forum (F30 / F32) | F30POST > Technical Forums > Mechanical Maintenance and TSBs: Break-in / Oil & Fluids / Servicing / TSBs and Service Bulletin > DIY Brake flush service?
European Auto Source
Post Reply
 
Thread Tools Search this Thread
      10-17-2017, 08:50 PM   #23
chaungo
=D
chaungo's Avatar
Canada
897
Rep
1,651
Posts

Drives: 13' 335ix
Join Date: Sep 2015
Location: Quebec

iTrader: (4)

Garage List
Quote:
Originally Posted by Bestodabest View Post
Never said i was a mechanic; but it certainly sounds like you're not. Do i smell an MSE Op?
I'm not, but I am a CF-18 technician, and I have friends who are vehicle techs on base that can confirm what you're saying is complete BS. Fluids are important to change after a certain time.


Quote:
Originally Posted by Bestodabest View Post
If your friend was involved in a collision that resulted from brake fluid boiling, then that's an operator problem.

I've been seeing those daily inspection checklists for 11 years now. I'm the guy you come and see when a fault is found. Please stay in your lane.

I stand by my previous statements. Unless you can produce evidence of QL5 Vehicle Technician training, a 310S or 310T red seal certificate, then you should keep your opinion to yourself. Tell your idiot friend to stop racing on public roadways.

You don't become an expert on the matter a year after figuring out how to swap brake pads.
Oh great, then someone needs to get a requalification.

My friend was driving normally and was going downhill when it happened. He is far from a boy racer.

I learn very quickly about stuff on my car, and in mechanics in general in a year. I did not say I was an expert, but I know enough to know that fluid changes are important.

If you don't want to do your fluids then by all means be that guy that will cause accidents. But do not encourage other people by providing false information.
__________________
2013 335i xDrive
Bootmod3 S2, Pure Stage 2, Pure Inlet, GFB DV+, AFE Pro Dry S Drop-in Filter, ER CP/TIC CP, ER Catless DP, CTS Turbo FMIC, Borla ATAK, Dinan Springs, Dinan Shockware
Appreciate 0
      10-17-2017, 09:51 PM   #24
Bestodabest
Private First Class
Canada
25
Rep
122
Posts

Drives: 2014 435i Xdrive
Join Date: Apr 2017
Location: Toronto

iTrader: (0)

Quote:
Originally Posted by chaungo View Post
I'm not, but I am a CF-18 technician, and I have friends who are vehicle techs on base that can confirm what you're saying is complete BS. Fluids are important to change after a certain time.




Oh great, then someone needs to get a requalification.

My friend was driving normally and was going downhill when it happened. He is far from a boy racer.

I learn very quickly about stuff on my car, and in mechanics in general in a year. I did not say I was an expert, but I know enough to know that fluid changes are important.

If you don't want to do your fluids then by all means be that guy that will cause accidents. But do not encourage other people by providing false information.
Chocking wheels once on OJT at Coldlake doesn't make you a "CF18 Technician".

That "certain time" isn't 2 years.

Your friend needs to learn what a downshift is.

The only thing you've learned in a year is how quickly banks will lend money to soldiers that sign lifetime contracts.
Appreciate 0
      10-17-2017, 10:14 PM   #25
Bestodabest
Private First Class
Canada
25
Rep
122
Posts

Drives: 2014 435i Xdrive
Join Date: Apr 2017
Location: Toronto

iTrader: (0)

I don't care.

You don't need to flush your brake fluid every 2 years. Buy the test strips to confirm.

/Thread.
Appreciate 0
      10-19-2017, 03:50 PM   #26
spitpilot
Private First Class
34
Rep
187
Posts

Drives: 2009 328I M sp, 2017 X1 M sp
Join Date: Jun 2010
Location: Reno/Tahoe

iTrader: (0)

Let's get focused back on technical issues rather than "gut feel"....
Here's an excerpt from a technical article about brake fluid, meassuring wet and dry boiling points etc that covers the topic well IMO...

4.0 When to Change Brake Fluid?
Many motor vehicle manufacturers recommend
checking brake fluid every 12 months, or changing
fluid every 24 months. The amount of moisture that
brake fluid absorbs depends on a number of factors
including the type of fluid, humidity, type of
brake hoses, condition of the seals and mileage.
Brake fluid will absorb 1% or more moisture per year
of service life. A two year old vehicle will have 2 to
3% water in the brake fluid. 3% water reduces the
boiling point of DOT 3 brake fluid by approximately
175F (97C). 3% water in DOT 4 brake fluid reduces
the boiling point by 162F (90C). (See Chart
next page)
Generally, the type of driving should influence when
to change brake fluid. If the vehicle is used for
towing, is driven in mountainous regions, or has an
ABS system it would be best to change the fluid
sooner. All vehicles should have the brake fluid
changed when the water exceeds the minimum wet
boil point. Motor vehicle manufacturers may recommend
brake fluid changes at lower water content/
higher boiling point than shown on the chart. OEM
service recommendations should be followed.


BMW reccomends 3 years for first flush and 2 year intervals there after...same as Audi/Vw...both use Bosch braking components (ABS valve blocks.) so I'd bet that Bosch has given some input to the car makers here about how to keep their components in top operating shape...Interesting to note both makes switched to requiring only DOT 4 LV (low viscosity) fluid at about the same time a few years back....so I'd guess Bosch drove that change as well....
Appreciate 0
      10-19-2017, 04:38 PM   #27
Polo08816
Colonel
882
Rep
2,658
Posts

Drives: 2014 335i M Sport
Join Date: Sep 2010
Location: MD

iTrader: (0)

Quote:
Originally Posted by chaungo View Post
Guess what, that's about over a year ago.

Guess who learned how to do more stuff within the year? And also saw more things? why do you think I'm defending my position on the brake fluid?

I've seen accidents happen because the brake fluid was so overdue, it boiled. One of my friend who hasn't swapped his brake fluid in 6 years was the vicitim of that, he had a e92 335i.



You don't have to do it yourself, I implied that if you know or don't know how to do it, just bring it to someone who does, or do it yourself.

Have you ever since a military vehicle checklist before you sign one out? Brake fluid is on the list and they tell you what is acceptable and what isn't.

My trade experience goes from normal DND vehicles to CF18s (no I'm not joking. Check out BMWTN and you'll know who I am) and guess what, the brakes on the CF18 are hydraulically operated, they swap the fluid every x amount of flights or depending if the filter has been triggered or not.

I'm not here to cause a argument, I'm just providing my own advice on maintaining the vehicle, I don't want people to start taking stupid advice of "neglecting" fluids. I don't want my family or friends to get into an accident because some idiot decided not to swap his brake fluid in 6 years because someone said it's useless to do so. The fact is if you leave your brake fluid alone and don't touch it, it will lose it's temperature of where it's supposed to boil, and it can cause an accident due to it overheating faster.

Don't cheap out on maintenance, especially on a 50k+ car. Will it hurt to swap brake fluid? No, but don't tell people it's useless when it isn't.

I almost forgot. You even mentioned coolant flushes are overrated.

I want you to swap out both the brake and coolant in the next 3-4 years and see how disgusting they are and tell me they're still good. Coolant is IMPORANT for our cars. If you don't swap it, guess your water pump and thermostat are going to go VERY early. Not to mention, your engine will now be prone to overheating. N55 are notorious for running hot.
Quote:
Originally Posted by Bestodabest View Post
If your friend was involved in a collision that resulted from brake fluid boiling, then that's an operator problem.

I've been seeing those daily inspection checklists for 11 years now. I'm the guy you come and see when a fault is found. Please stay in your lane.

I stand by my previous statements. Unless you can produce evidence of QL5 Vehicle Technician training, a 310S or 310T red seal certificate, then you should keep your opinion to yourself. Tell your idiot friend to stop racing on public roadways.

You don't become an expert on the matter a year after figuring out how to swap brake pads.
I'm going to have to agree with Bestodabest here.

I've never seen someone on the street get into an accidentally solely because their brake fluid boiled. Even under track use in the middle of an 90F summer, my rotors reach 350F at most and calipers are at 150-200F (measured about 1-2 minutes after coming off the track). Not nearly enough to boil brake fluid on the street unless if you're dragging your brakes the entire time.

I'm more inclined to believe that this "friend" got into an accident because of operator error than boiling brake fluid.
Appreciate 1
      10-19-2017, 04:47 PM   #28
Bestodabest
Private First Class
Canada
25
Rep
122
Posts

Drives: 2014 435i Xdrive
Join Date: Apr 2017
Location: Toronto

iTrader: (0)

Quote:
Originally Posted by spitpilot View Post
Let's get focused back on technical issues rather than "gut feel"....
Here's an excerpt from a technical article about brake fluid, meassuring wet and dry boiling points etc that covers the topic well IMO...

4.0 When to Change Brake Fluid?
Many motor vehicle manufacturers recommend
checking brake fluid every 12 months, or changing
fluid every 24 months. The amount of moisture that
brake fluid absorbs depends on a number of factors
including the type of fluid, humidity, type of
brake hoses, condition of the seals and mileage.
Brake fluid will absorb 1% or more moisture per year
of service life. A two year old vehicle will have 2 to
3% water in the brake fluid. 3% water reduces the
boiling point of DOT 3 brake fluid by approximately
175F (97C). 3% water in DOT 4 brake fluid reduces
the boiling point by 162F (90C). (See Chart
next page)
Generally, the type of driving should influence when
to change brake fluid. If the vehicle is used for
towing, is driven in mountainous regions, or has an
ABS system it would be best to change the fluid
sooner. All vehicles should have the brake fluid
changed when the water exceeds the minimum wet
boil point. Motor vehicle manufacturers may recommend
brake fluid changes at lower water content/
higher boiling point than shown on the chart. OEM
service recommendations should be followed.


BMW reccomends 3 years for first flush and 2 year intervals there after...same as Audi/Vw...both use Bosch braking components (ABS valve blocks.) so I'd bet that Bosch has given some input to the car makers here about how to keep their components in top operating shape...Interesting to note both makes switched to requiring only DOT 4 LV (low viscosity) fluid at about the same time a few years back....so I'd guess Bosch drove that change as well....
An excellent write up, however under normal conditions (street use) brake fluid shouldn't be boiling after 2 years. Even with 3% water absorption, the fluid is still significantly above the boiling point of water.
Appreciate 0
      10-19-2017, 04:49 PM   #29
Bestodabest
Private First Class
Canada
25
Rep
122
Posts

Drives: 2014 435i Xdrive
Join Date: Apr 2017
Location: Toronto

iTrader: (0)

Quote:
Originally Posted by Polo08816 View Post
I'm going to have to agree with Bestodabest here.

I've never seen someone on the street get into an accidentally solely because their brake fluid boiled. Even under track use in the middle of an 90F summer, my rotors reach 350F at most and calipers are at 150-200F (measured about 1-2 minutes after coming off the track). Not nearly enough to boil brake fluid on the street unless if you're dragging your brakes the entire time.

I'm more inclined to believe that this "friend" got into an accident because of operator error than boiling brake fluid.
He's already admitted that his friend was traveling down an incline when the incident happened; probably rode the brakes the entire way down instead of selecting an appropriate gear. You hear about it all the time out west where they've started using run-away lanes for commercial vehicles.
Appreciate 0
      10-19-2017, 09:54 PM   #30
dreamspeed
Lieutenant Colonel
dreamspeed's Avatar
United_States
185
Rep
1,604
Posts

Drives: 6MT
Join Date: Jul 2012
Location: Los Angeles

iTrader: (0)

I don't think you will get into a catastrophic accident if you don't change your brake fluid in 2-3 years but it won't hurt.

A friend recently changed his brake fluid after 3 years and the reading on his brake fluid tester was less than 3% water.

I just changed my brake fluid after 4.5 years and it read over 5%.
__________________
Appreciate 0
      10-19-2017, 11:11 PM   #31
John in VA
Captain
183
Rep
603
Posts

Drives: '13 328i xDrive
Join Date: Jul 2007
Location: Leesburg, VA

iTrader: (2)

My father finally had his brake fluid in his Cougar XR-7 changed after 25 years! But he is & drives like an old man. When you drive your car daily the degradation in response/performance can be difficult to notice as it happens incrementally over time. If you drive in a spirited fashion, changing fluid every 2 years can keep you safe & protect the brake components from possible corrosion due to the hygroscopic nature of brake fluid. Brake fluid is cheap, and a pressure bleeder makes the job a breeze.
__________________
_______________________________________________
2013 BMW 328i xDrive in Orion Silver/Venetian Beige - Premium & Cold Weather Packages, Navigation System
Appreciate 1
Polo08816881.50

      10-20-2017, 12:03 PM   #32
spitpilot
Private First Class
34
Rep
187
Posts

Drives: 2009 328I M sp, 2017 X1 M sp
Join Date: Jun 2010
Location: Reno/Tahoe

iTrader: (0)

Quote:
Originally Posted by Bestodabest View Post
An excellent write up, however under normal conditions (street use) brake fluid shouldn't be boiling after 2 years. Even with 3% water absorption, the fluid is still significantly above the boiling point of water.
I should hope the fluid boils "significantly above water"! Ever measured brake component temps after a long downhill blast through some serious mountains?...Way above 212 F for sure...then throw in towing a trailer and you're dissipating some serious heat in "street use"...

But I'm thinking the more frequent flushing being required by BMW and other car makers today is more to keep sensitive modern ABS components in good health and doing their ABS/traction control duties, rather than being driven by brake fade considerations.
Appreciate 0
      10-20-2017, 12:22 PM   #33
Orion4
Captain
United_States
173
Rep
883
Posts

Drives: 2013 335i Sport Line Sedan
Join Date: Aug 2009
Location: Melbourne, FL

iTrader: (0)

For me, it simple. Change every 2-3 years to retain as long as possible a good conditioned brake system minimizing the chance of degradation and corrosion. It's cheap insurance on a safety system.

As noted the degradation of brake fluid has a number of variables: driving style, temp, ambient humidity, driving load, etc. I've disassembled some systems that have not had fluid changed in 7-8 years and the components are fine. Others have looked like crap after 3-4. Varies.

I choose to error on the conservative (non-political) side. To each their own and reap the "benefits" of your decisions!
Appreciate 0
      10-20-2017, 01:07 PM   #34
Bestodabest
Private First Class
Canada
25
Rep
122
Posts

Drives: 2014 435i Xdrive
Join Date: Apr 2017
Location: Toronto

iTrader: (0)

Quote:
Originally Posted by spitpilot View Post
I should hope the fluid boils "significantly above water"! Ever measured brake component temps after a long downhill blast through some serious mountains?...Way above 212 F for sure...then throw in towing a trailer and you're dissipating some serious heat in "street use"...

But I'm thinking the more frequent flushing being required by BMW and other car makers today is more to keep sensitive modern ABS components in good health and doing their ABS/traction control duties, rather than being driven by brake fade considerations.
This all boils down to proper operation of the vehicle (pun intended).

Driving through mountainous areas requires a certain driving technique that relies on correct gear selection over the use of brakes. There's no reason for you to suffer brake fade if you're driving properly.

What brake component were you measuring the temperature of during this "downhill blast"?

You think the manufacturer was more inclined to publish their brake flush interval to preserve system components (that will EASILY last beyond the warranty period), over pressure from consumer and government legislation and lawsuits?
Appreciate 0
      12-17-2017, 06:44 PM   #35
jparnes1
Colonel
jparnes1's Avatar
No_Country
99
Rep
2,236
Posts

Drives: 2016 340i, 2012 Z4 35i
Join Date: Jan 2010
Location: NY

iTrader: (1)

Reviving this thread...a friend with a 2017 330 (B48 engine) told me that to do a brake flush in this car he thinks he needs to use software to perform the bleed. He has no traditional brake fluid reservoir and you have to perform the service by controlling the ECU. Can anyone confirm this?
__________________
2016 340i XDrive, EBII/black, 6 MT, M Sport, Track Handling, Cold Weather, Tech, Lighting, Driver Assistance Plus.

2012 Z4 35i, ED 2/24/2012, Melbourne Red Metallic, Black Leather, Carbon Trim, 6MT, M Sport, CW, PP, PS, NAV, CA.
Appreciate 0
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


All times are GMT -4. The time now is 07:12 PM.




f30post
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST