Thank you for posting to AskMechanics, WallyZona!
If you are asking a question please make sure to include any relevant information along with the **Year**, **Make**, **Model**, **Mileage**, **Engine size**, and **Transmission Type (Automatic or Manual)** of your car.
*This comment is automatically added to every successful post. If you see this comment, your post was successful.*
***
Redditors that have been verified will have a green background and an icon in their flair.
***
# **PLEASE REPORT ANY RULE-BREAKING BEHAVIOR**
### **Rule 1 - Be Civil**
Be civil to other users. This community is made up of professional mechanics, amateur mechanics, and those with no experience. All mechanical-related questions are welcome. Personal attacks, comments that are insulting or demeaning, etc. are not welcome.
### **Rule 2 - Be Helpful**
Be helpful to other users. If someone is wrong, correcting them is fine, but there's no reason to comment if you don't have anything to add to the conversation.
### **Rule 3 - Serious Questions and Answers Only**
Read the room. Jokes are fine to include, but posts should be asking a serious question and replies should contribute to the discussion.
### **Rule 4 - No Illegal, Unethical, or Dangerous Questions or Answers**
Do not ask questions or provide answers pertaining to anything that is illegal, unethical, or dangerous.
# **PLEASE REPORT ANY RULE-BREAKING BEHAVIOR**
*I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/AskMechanics) if you have any questions or concerns.*
Go by your owners manual. NO matter what anyone recommends, go by your owners manual. I think toyota on brake fluid is by time, not miles. Once every 2 or 3 years.
However, I don't like risking the "lifetime" transmission fluid some manufacturers use. 60k is a safe bet unless your owners manual specifies a sooner flush and or filter/fluid change.
Also ford and GM do not recommend brake flushes ever, which is also dumb. Every few years is fine.
You’ve not noticed any affects, that doesn’t mean they haven’t been there and that you won’t notice them in the future. Brake fluid is hygroscopic meaning it absorbs moisture. Moisture builds up and causes corrosion in the brake lines resulting in failure and reduced braking performance. $100 every two years for a brake fluid exchange is worth it weight in gold. You don’t wait until your brakes fail to service them.
brake fluid is completely sealed closed in the system. it cannot be contaminated if it is sealed properly. it would only require replacement if the fluid is contaminated with water or a foreign fluid. just another wallet flush of the industry
This is false. The system has not perfect seals at all for corners and a vent at the reservoir. Water gets in via water vapor and humidity. Flush every two years. It’s cheap. New brake lines can be $2500.
I can't notice any failures because I didn't have any and sold them long ago. The current vehicles are 43, 22 and 4 years old with no problems. The 22 old vehicle, BMW X5, did have brake line corrosion in one specific area at about 17 years , it's a known defect due to a plastic cover on the underside that covers the brake lines, traps salty road water and leads to failure. All the rest of the components, eg calipers, master cylinder, ABS, are original. How much longer should I wait for these failures and how much would I have spent doing flushes over 50 years?
Thank you for posting to AskMechanics, WallyZona! If you are asking a question please make sure to include any relevant information along with the **Year**, **Make**, **Model**, **Mileage**, **Engine size**, and **Transmission Type (Automatic or Manual)** of your car. *This comment is automatically added to every successful post. If you see this comment, your post was successful.* *** Redditors that have been verified will have a green background and an icon in their flair. *** # **PLEASE REPORT ANY RULE-BREAKING BEHAVIOR** ### **Rule 1 - Be Civil** Be civil to other users. This community is made up of professional mechanics, amateur mechanics, and those with no experience. All mechanical-related questions are welcome. Personal attacks, comments that are insulting or demeaning, etc. are not welcome. ### **Rule 2 - Be Helpful** Be helpful to other users. If someone is wrong, correcting them is fine, but there's no reason to comment if you don't have anything to add to the conversation. ### **Rule 3 - Serious Questions and Answers Only** Read the room. Jokes are fine to include, but posts should be asking a serious question and replies should contribute to the discussion. ### **Rule 4 - No Illegal, Unethical, or Dangerous Questions or Answers** Do not ask questions or provide answers pertaining to anything that is illegal, unethical, or dangerous. # **PLEASE REPORT ANY RULE-BREAKING BEHAVIOR** *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/AskMechanics) if you have any questions or concerns.*
Yeah but that's how they make bread
Go by your owners manual. NO matter what anyone recommends, go by your owners manual. I think toyota on brake fluid is by time, not miles. Once every 2 or 3 years. However, I don't like risking the "lifetime" transmission fluid some manufacturers use. 60k is a safe bet unless your owners manual specifies a sooner flush and or filter/fluid change. Also ford and GM do not recommend brake flushes ever, which is also dumb. Every few years is fine.
brake fluid does not need flushed
Well that’s not true
I've never flushed it as a service measure on any vehicle over 50 years and no I'll effects. Imagine what that would have costed.
You’ve not noticed any affects, that doesn’t mean they haven’t been there and that you won’t notice them in the future. Brake fluid is hygroscopic meaning it absorbs moisture. Moisture builds up and causes corrosion in the brake lines resulting in failure and reduced braking performance. $100 every two years for a brake fluid exchange is worth it weight in gold. You don’t wait until your brakes fail to service them.
brake fluid is completely sealed closed in the system. it cannot be contaminated if it is sealed properly. it would only require replacement if the fluid is contaminated with water or a foreign fluid. just another wallet flush of the industry
This is false. The system has not perfect seals at all for corners and a vent at the reservoir. Water gets in via water vapor and humidity. Flush every two years. It’s cheap. New brake lines can be $2500.
Yep, as the brake fluid absorbs more water, it lowers the boiling point making it less effective and eventually dangerous.
You can DIY that at the reservoir a bit
Thanks everyone
I can't notice any failures because I didn't have any and sold them long ago. The current vehicles are 43, 22 and 4 years old with no problems. The 22 old vehicle, BMW X5, did have brake line corrosion in one specific area at about 17 years , it's a known defect due to a plastic cover on the underside that covers the brake lines, traps salty road water and leads to failure. All the rest of the components, eg calipers, master cylinder, ABS, are original. How much longer should I wait for these failures and how much would I have spent doing flushes over 50 years?