Brake Fluid change interval?

[Grimes]

I'm trying to setup a little self-guide of intervals for fluids just as another deciding factor for deciding on whether a change is warranted or not, and am stuck on brake fluid. I know it is good to check its color and level and moisture % if possible, but is there a general guideline for mileage/time? I've already had a shop try to talk me into a flush 2 months after I had one, so I'm sure I just look like easy pickins, and I want to be able to say "No thank you" with confidence and maybe have a few more nice meals a year.

I've seen lots of 2 years, 3 years, and fewer 5 years. However, people are also saying no change, and domestic manufacturers (including GM) don't even mention it (a GM press release stated it wasn't necessary due to additives in DOT 3 reducing moisture absorption).

So, what is y'alls take?

Thanks for the input.

 

[AZSCTACO]

I have 187k on my 07' and have never had a shop flush mine. What I've been doing since day one is every other oil change, I use a turkey baster and take out as much fluid out of the reservoir and replace it with fresh stuff. Takes 2 minutes and I know it's done right.

 

[Grimes]

You don't bother bleeding brakes or anything like that? I'm hearing more and more about simply using a turkey baster for most fluid changes, and doing it frequently enough makes a true flush unnecessary. Anyone else suggest this?

 

[AZSCTACO]

I've never had the brakes bleed. I also do this with my power steering fluid. Fluid is cleeeeeean

 

[Grimes]

I've never had the brakes bleed. I also do this with my power steering fluid. Fluid is cleeeeeean

Do you do the PS every oil change too, or just when it is looking like it needs it? Is moisture buildup also the concern for PS fluid?

 

[AZSCTACO]

I do the PS fluid every other as well. I've never experienced moisture buildup....but I also live in dry ass Arizona.

 

[about20ninj45]

Do you do the PS every oil change too, or just when it is looking like it needs it? Is moisture buildup also the concern for PS fluid?

I work on brake dynomometers/tester/boosters all the time, its part of my profession. I will simply state that everytime you introduce air into the lines via brake job, you should flush the system. The reason for this being is that with dot 3//4, tiny air bubbles get stuck in the viscous fluid and become trapped causing more wear and less performance over time. Even with Dot 3 sitting on a shelf at autozone, the fluid still absorbs moisture through a sealed container. Granted its plastic, but it will still do the same inside of a vehicle.Brake fluid is hygroscopic (absorbs moisture from the air) and will saturate which changes its boiling point and could cause valves in the master cylinder to go bad. For sanity reason, drain some of your brake fluid into a beaker or graduated cylinder ( or glass jar ) and check for not only color, but separation of fluid in layers. If it is, your brake fluid is contaminated and should flushed/discarded

Hope that helps

 

[Grimes]

I appreciate the input guys.

Regarding copper strip testing and electronic moisture testing, do y'all think these are worth it if you keep to a regular schedule (2-3 years, 24-36k) for brake fluid? At this point I'm thinking of just keeping an eye on the fluid, maybe refilling just the reservoir, and seeing if the shop pushes a flush. Whether or not they suggest a flush I'll try to get proof of moisture and/or copper test to keep from buying the $78 tube of strips. I'm not trying to be cheap or beat the system, I am just at a point where I don't trust a word out of their mouths with all of the national and local stories in the air.

Minimal knowledge about brakes. At what point does a brake job involve opening the lines? Does that include pads?

Thanks again.

 

[about20ninj45]

I appreciate the input guys.

Regarding copper strip testing and electronic moisture testing, do y'all think these are worth it if you keep to a regular schedule (2-3 years, 24-36k) for brake fluid? At this point I'm thinking of just keeping an eye on the fluid, maybe refilling just the reservoir, and seeing if the shop pushes a flush. Whether or not they suggest a flush I'll try to get proof of moisture and/or copper test to keep from buying the $78 tube of strips. I'm not trying to be cheap or beat the system, I am just at a point where I don't trust a word out of their mouths with all of the national and local stories in the air.

Minimal knowledge about brakes. At what point does a brake job involve opening the lines? Does that include pads?

Thanks again.

When replacing pads/rotors or brake lines. Its always a good rule of thumb to flush the lines for any contaminates prior to install. Any time you see a leak or bleed, remember, if fluid can get out, air can get in. Also, make sure your brake reservoir cap is completely sealed, this mainly the source of moisture intruding the system.


Copper strip testing and electronic moisture testing is overkill. I would just inspect the fluid after bleeding the system. Id recommend brake fluid change intervals every 2 years.

 

[Grimes]

Probably going to go at this tomorrow or Tuesday, but am getting cold feet with replacing flushes with a turkey baster job. Anyone else able to give their experience with just suctioning it out and skipping the flush? The point of this switch is to save money and avoid potentially unnecessary shop work. But I don't want to save $200 here and there if it means a looming $2000 down the road.