Confirmed Brake Fluid is lifetime! Save your money

[ants_oz]

For the education of those who were unaware - as moisture levels increase in the brake fluid, the fluid loses its resistance to boiling. Brake fluid most often boils in the calliper, immediately behind the piston/s as heat is transferred from the pad friction material, to the steel backing plate, and into the piston. And when it boils, there is often no warning. Your brakes just "go away". One moment you are braking well, the next you are on a sled without brakes. But with a steering wheel...

[Joshdub]

Paying $200-300 for a brake fluid flush is getting ripped. It takes no more than half an hour with a pressure bleeder (which is a ~$50 tool) and a ~$15 bottle of brake fluid.

Like others have stated, over time your fluid is getting saturated with moisture and the boiling point is lowering significantly. This isn't some group of bean counters trying to coax more money out of people, it's chemistry. Once you boil your fluid under heavy/panic braking, well let's just hope your Ebrake is up to the challenge. Just because your brakes "work" or "feel as good as new" doesn't mean they are going to be there when you need them most. Not to mention your corroding hardlines and calipers.

You have literally -zero- evidence to back up what you are claiming. Once you have the fluid tested and lines/calipers examined (internally, not the visual exterior like you were talking about), then you can try to disprove science. Until then, it's just reckless conjecture.

[crystalworks]

Originally Posted by Joshdub

Paying $200-300 for a brake fluid flush is getting ripped. It takes no more than half an hour with a pressure bleeder (which is a ~$50 tool) and a ~$15 bottle of brake fluid.

You have literally -zero- evidence to back up what you are claiming. Once you have the fluid tested and lines/calipers examined (internally, not the visual exterior like you were talking about), then you can try to disprove science. Until then, it's just reckless conjecture.

Oh, I agree on the price being high... but if you are paying it every 3 or 4 years... it's a small price to pay. Plus, lol in the x5 world... anything able to done at a shop for less than $1000 is cheap.

And you don't even need a pressure bleeder if you are gravity bleeding... or using the 2 person method. More money savings. I have a vacuum bleeder ($30) but still prefer the 2 person method when possible.

Also agree about it being a little reckless to post a thread title like the above... especially without any scientific evidence to back it up.

[Joshdub]

Originally Posted by crystalworks

Oh, I agree on the price being high... but if you are paying it every 3 or 4 years... it's a small price to pay. Plus, lol in the x5 world... anything able to done at a shop for less than $1000 is cheap.

And you don't even need a pressure bleeder if you are gravity bleeding... or using the 2 person method. More money savings. I have a vacuum bleeder ($30) but still prefer the 2 person method when possible.

Also agree about it being a little reckless to post a thread title like the above... especially without any scientific evidence to back it up.

That is true as well. The 2 person method is the cheapest, but sometimes it can be tricky to get a second set of hands, or feet in this case, to help out. I have had mity vac vacuum bleeders in the past and they worked great, they have just never lasted very long even with proper cleaning. I have been meaning to buy a pressure bleeder to replace my defunct vac one.

[StephenVA]

There is no question that a simple low cost effective way to maintain superior braking performance is brake fluid replacement semi annually every 24 months/36,000 miles. Prevents issues like caliper piston rust lock ("frozen calipers") etc. Also a great way to learn more about your vehicle and the status of the brake pads, lines, hoses, master cyl, etc.

Now, can you drive a car without doing some services? Of course! I have seen multiple vehicles driven well past 100K without any brake work other than hanging a set of pads on it. Would I do it on my car? Hell no, I enjoy my life too well.

[cn90]

While I can see that the O.P. runs to 200K w/o hydraulic brake issues, I still replace my brake fluid every 2-3y/24K miles or so. Maybe this is overkill but I have done it for years.

Now back to the original post, I can see some reasons why the O.P.'s brake is still fine after 200K...

1. Las Vegas has dry weather for the most part.

2. Water can only enters the hydraulic system at 2 points:

a. The reservoir cap: when brake pads wear down, the pistons extend further, fluid in reservoir goes down, so atmospheric air (and some water in the air) enters the reservoir. Not a big deal as the amount of water is rather small.

b. At the caliper areas b/c the caliper is exposed to rain water all the time.
In order for water to enter the caliper itself, it has to go past the:
* rubber boot
* piston seal itself

Usually the rubber boot is torn with time/heat...then water enters the area behind the boot, then the pistons become corroded ---> seal damaged.

So, I can see that if one lives in dry climate such as Nevada or Arizona, one can argue to replace brake fluid at less frequent intervals.

I live in the snow belt (salt) and tons of rain in the summer, thus the 2-3y/24K schedule.

My 2 pennies...

[Qsilver7]

BTW...does regular DOT 4 brake fluid turn from it's light amber color to a dark murky color as it absorbs moisture? Or does the darkened fluid occur for other reasons? Obviously if you're using a colored brake fluid (like blue)...this color identification won't apply.

Just some FYI to add to the discussion...especially those that were unaware of the hygroscopic nature of brake fluid and why BMW has the 2 yr recommendation to flush:

(from owners manual)




(from BMW TIS)

[admranger]

Originally Posted by Qsilver7

BTW...does regular DOT 4 brake fluid turn from it's light amber color to a dark murky color as it absorbs moisture? Or does the darkened fluid occur for other reasons? Obviously if you're using a colored brake fluid (like blue)...this color identification won't apply.

Just some FYI to add to the discussion...especially those that were unaware of the hygroscopic nature of brake fluid and why BMW has the 2 yr recommendation to flush:

(from owners manual)

(from BMW TIS)

I have observed brake fluid getting darker over time but I don't know if there is any correlation to moisture or not. Brake fluid gets dark after high temps too (e.g., track days) in my expience.

Since I flush the system before my all too infrequent track days on the 2002 M3, I usually run any extra out of the pressure bleeder through the X5 brakes. An open can of brake fluid is no good unless you purge the air in the container with dry nitrogen.

Use it or lose it is my motto with an open bottle of brake fluid, so I use it all up!

[bcredliner]

I have used the two person push the pedal method, the vacuum bleeding and pressure bleeding. I like pressure bleeding because it doesn't require coordination with another person, and I don't have to worry about drawing more air into the system or refilling the master cylinder. Chain auto parts stores rent bleeders, usually with a 100% refund when it is returned.

A sample of one is never enough to draw a valid conclusion. In this case there are years of expert documentation stating brake fluid should be changed at some interval. Though I doubt it, there might be someone that believes you and does not change their fluid resulting in a lack of braking crash. I agree this thread is reckless.

[chivas]

Question about bleeding brakes since we are on this topic. Does the ABS pump module need to be on? In my bronco, it requires abs module to cycle each pump to each wheel to bleed. I don't recall doing this to my 39... Figure it's the same procedure?? Thanks