Brake fluid - need to change?

[Harold Hubbard]

To add to my previous post: With the salt and corrosion problems here, if you went to bleed and flush the system, you would most likely encounter at least one stuck bleeder, and maybe wind up having to replace a caliper or wheel cylinder because of it.

 

[Levi81]

To properly flush the system you will need a scan tool with bidirectional controls to activate the ABS pump. To do the job as it should be done you will need a Brake fluid flush machine. There are a few vacuum and low pressure systems on the market they do not do a good job at this other than easy on the pocketbook. I am a firm believer in flushing brake fluid along with that tooled up well to perform the job.

hydroscopic = the fluid will mix with water, dot5 synthetic does not so the issue will be as you stated water will collect in spots of the brake system. Either way water is an issue. On the black fluid its a reaction to metal most all the time I see this is when aluminum calipers are used.

Back to hydroscopic what's the best thing to clean brake parts when soaked/covered with brake fluid. Water it is noting will match it.


I flush for all the right reasons its part of the gig... To properly flush the system you will need a scan tool with bidirectional controls to activate the ABS pump/valves. To do the job as it should be done you will need a Brake fluid flush machine. There are a few vacuum and low pressure systems on the market; they do not do a good job at this other than being easy on the pocketbook. I am a firm believer in flushing brake fluid along with that tooled up well to perform the job.

I've been told that I should have my brake fluid changed out on my 2014 F150.
I have 120k miles on it.

Is this really necessary. I think it's a waste of money. Am I wrong?

Of all the hundreds of thousands of miles I have put on vehicles, I have never had the brake fluid flushed. Only when I changed calipers have I flushed the lines out myself.
Maybe some vehicles need it. I think it’s not necessary. I think it’s an upsell dealers try to promote

To add to my previous post: With the salt and corrosion problems here, if you went to bleed and flush the system, you would most likely encounter at least one stuck bleeder, and maybe wind up having to replace a caliper or wheel cylinder because of it.

i live in a rust belt state. When I install new calipers I remove the bleeder and coat the threads with anti seize. I also coat all the threads on lines, hoses and banjo bolts.
So far I have never had a problem

 

[sotxbill]

While driving through the mountains in a ford based motorhome, I observed my brake pedal getting mushier and dropping after a long braking going down the 5 mile passes. I ended up with no pedal as it went all the way to the floor... I pumped it up and barely made a safe stop at a pull off. It turned out the moisture in the fluid begin to boil into gas, thus loss of pedal... After 40 minutes, magically the pedal started coming back as it cooled and the moisture returned to fluid. SO... although most of the time you never have to brake that much or that long, the accumulated moisture can and does cause brake failure.. Not to mention the other problems with rust and corrosion in the system. That model of ford also had a problem with one disc pad wearing out due to the caliper mounting pins getting sludge and not allowing the caliper to slide on the pins to center itself on the disc properly. IF... you live in a humid area, I would recommend you follow the factory recommended fluid change interval... On some cars, its every 12 months... but I certainly would think about it if you also live in the mountains.

 

[Levi81]

While driving through the mountains in a ford based motorhome, I observed my brake pedal getting mushier and dropping after a long braking going down the 5 mile passes. I ended up with no pedal as it went all the way to the floor... I pumped it up and barely made a safe stop at a pull off. It turned out the moisture in the fluid begin to boil into gas, thus loss of pedal... After 40 minutes, magically the pedal started coming back as it cooled and the moisture returned to fluid. SO... although most of the time you never have to brake that much or that long, the accumulated moisture can and does cause brake failure.. Not to mention the other problems with rust and corrosion in the system. That model of ford also had a problem with one disc pad wearing out due to the caliper mounting pins getting sludge and not allowing the caliper to slide on the pins to center itself on the disc properly. IF... you live in a humid area, I would recommend you follow the factory recommended fluid change interval... On some cars, its every 12 months... but I certainly would think about it if you also live in the mountains.

How do you know it was not the brake fluid itself boiling?

 

[Hobo,NC]

Of all the hundreds of thousands of miles I have put on vehicles, I have never had the brake fluid flushed. Only when I changed calipers have I flushed the lines out myself.
Maybe some vehicles need it. I think it’s not necessary. I think it’s an upsell dealers try to promote

i live in a rust belt state. When I install new calipers I remove the bleeder and coat the threads with anti seize. I also coat all the threads on lines, hoses and banjo bolts.
So far I have never had a problem

And put a

Brake Bleeder Screw Cap on it.​

 

[Ericp351]

Wow- lots of words re. a simple question. Note: Dot 5 should not be a factor here. 5.1 can be thought as pricier Dot 4, and compatible. Good stuff, higher boiling point, again- unlikely ever to see insides of this rig. Yes- break fluid 3,4,5.1 can and will pull water. Yes- water in break sys. = bad. Yes- big bug-o-boo with ABS systems, especially if they have a pump. Yes- flushing = cheap to do. Jaguar, 4 piston calipers = flush! Crappy mini-van, why? Did somebody drive a 1950's rusty farm truck for 3 decades with but honey as brake fluid?- Probably. My X wife's rig- leave it! Not rocket science!!

 

[sotxbill]

How do you know it was not the brake fluid itself boiling?

dot 3 brake fluid boils at 401 F... wet or contaminated dot 3 boils at 284F or even lower pending on how much moisture and has the water started to settle out, then it boils near to 220 F. Either way I flushed the system, lubed the pins, changed the pads and my shorts..... and never had the problem again. https://search.yahoo.com/yhs/search...9_FFW_ZZ&grd=1&p=boiling+point+of+brake+fluid

 

[showcrop]

Wow- lots of words re. a simple question. Note: Dot 5 should not be a factor here. 5.1 can be thought as pricier Dot 4, and compatible. Good stuff, higher boiling point, again- unlikely ever to see insides of this rig. Yes- break fluid 3,4,5.1 can and will pull water. Yes- water in break sys. = bad. Yes- big bug-o-boo with ABS systems, especially if they have a pump. Yes- flushing = cheap to do. Jaguar, 4 piston calipers = flush! Crappy mini-van, why? Did somebody drive a 1950's rusty farm truck for 3 decades with but honey as brake fluid?- Probably. My X wife's rig- leave it! Not rocket science!!

Simple? maybe but you still got it wrong. Crappy mini van will still kill if brakes fail. And water, which gets in easily makes them fail.

 

[Levi81]

Simple? maybe but you still got it wrong. Crappy mini van will still kill if brakes fail. And water, which gets in easily makes them fail.

Everyone is talking about water in the brake system. I have never experienced this. No matter how long the vehicle sat it time between changing calipers

 

[Levi81]

dot 3 brake fluid boils at 401 F... wet or contaminated dot 3 boils at 284F or even lower pending on how much moisture and has the water started to settle out, then it boils near to 220 F. Either way I flushed the system, lubed the pins, changed the pads and my shorts..... and never had the problem again. https://search.yahoo.com/yhs/search...9_FFW_ZZ&grd=1&p=boiling+point+of+brake+fluid

I have never had moistures in any brake system

 

[Hobo,NC]

Everyone is talking about water in the brake system. I have never experienced this. No matter how long the vehicle sat it time between changing calipers

Brake fluid absorbs moisture it becomes part of the composition. Its like making your favorite mixed drink. Dot 5 does not mix its like adding water to oil they do not become as one.

 

[Ericp351]

Everyone is talking about water in the brake system. I have never experienced this. No matter how long the vehicle sat it time between changing calipers

MAYBE you would NOT be changing calipers IF you flushed the fluid!!! That is the point! As far as mini-vans: ain't those for the heave and uncool? Relevant??

 

[Hobo,NC]

Everyone is talking about water in the brake system. I have never experienced this. No matter how long the vehicle sat it time between changing calipers

I have never seen water in the system I do know water will mix with the fluid. One of the tricks I learned early on at a truck shop I worked at early on was to use a water hose to clean the brakes with. This was before we learned blowing them of with air was harmful. We still blew them clean if you knew you had a wheel cylinder leak yo took it apart outside hosed it off once dry not a trace of brake fluid could be found. If I get brake fluid on my floor I pour water on it and mop it up with water only all the brake fluid will be gone. If I were to rebuild a brake part the first thing I hit it with is water, it magic as it cleans the part right up. The same if I spill brake fluid on the car hit with water its gone. Water is an enemy and more so in the south with its humility.

Its a rare event to rebuild a brake part anymore so I spec that's why this is not seen as useful. I have a old safety kleen brake cleaning machine it uses WATER as the main cleaner.

 

[Levi81]

Wow- lots of words re. a simple question. Note: Dot 5 should not be a factor here. 5.1 can be thought as pricier Dot 4, and compatible. Good stuff, higher boiling point, again- unlikely ever to see insides of this rig. Yes- break fluid 3,4,5.1 can and will pull water. Yes- water in break sys. = bad. Yes- big bug-o-boo with ABS systems, especially if they have a pump. Yes- flushing = cheap to do. Jaguar, 4 piston calipers = flush! Crappy mini-van, why? Did somebody drive a 1950's rusty farm truck for 3 decades with but honey as brake fluid?- Probably. My X wife's rig- leave it! Not rocket science!!

Neither is sentence syntax

 

[Levi81]

MAYBE you would NOT be changing calipers IF you flushed the fluid!!! That is the point! As far as mini-vans: ain't those for the heave and uncool? Relevant??

I usually get 100k out of a set of calipers.

 

[Fixingfarmer]

Yeah see that right there. Introducing water to the system is how it gets there at least in my climate be it the caps accidentally not on right or cleaning. I also have never ever experienced this. How does one get it out? Pull a vacuum on it like an ac pump. How longs it take to boil it out? 15 minutes I’d say just like ac system water is water. Any idea how much fluid you would be pulling through with a pump? Per line? It’s not sealed you say so it’s going to be more difficult to hold a vacuum? Sounds like something not to be done. Eventually it will work itself down to the bleeders and come out but likely a month later you will need to bleed again. Which will mostly take care of that...This is also why it’s either me or one other local person in this whole darn world who will touch the brakes on my vehicles. You just don’t know what the plan is. Not arguing too much with the people from the south I love the weather but wouldn’t bleeding it every couple years negate this? Here in Iowa when the crops growing we have some amazing humidity for this far north as well for about 4 months if you come here in august you will never come back but we do also get a break from it.

 

[Ericp351]

Humidity = water in air. Brake system is vented- by design, or in practice. Air + water + brake fluid + time = brake fluid with water. Far from rocket science. Water in brake fluid = corrosion + lower boiling point + plugged up stuff. Plugged up stuff and/ or boiling fluid- when you need same most- = bad. Brake fluid = cheap. Other parts, not so much. Crumpled cool car/ truck = bad. Down time = bad. Crumpled/ broke mini van = , who cares! Ever change hyd oil, or gear oil? Same concept! Post script- Rock on.

 

[sotxbill]

Everyone is talking about water in the brake system. I have never experienced this. No matter how long the vehicle sat it time between changing calipers

DOT 3, 4, and 5.1 brake fluids are hygroscopic. That means they absorb water from the humidity in the air around them. Even with the brake reservoir lid tightly sealed, eventually enough moisture will contaminate the fluid. https://search.yahoo.com/yhs/search...d=1&p=how+does+water+get+into+the+brake+fluid

 

[sotxbill]

Wow- lots of words re. a simple question. Note: Dot 5 should not be a factor here. 5.1 can be thought as pricier Dot 4, and compatible. Good stuff, higher boiling point, again- unlikely ever to see insides of this rig. Yes- break fluid 3,4,5.1 can and will pull water. Yes- water in break sys. = bad. Yes- big bug-o-boo with ABS systems, especially if they have a pump. Yes- flushing = cheap to do. Jaguar, 4 piston calipers = flush! Crappy mini-van, why? Did somebody drive a 1950's rusty farm truck for 3 decades with but honey as brake fluid?- Probably. My X wife's rig- leave it! Not rocket science!!

Yeah see that right there. Introducing water to the system is how it gets there at least in my climate be it the caps accidentally not on right or cleaning. I also have never ever experienced this. How does one get it out? Pull a vacuum on it like an ac pump. How longs it take to boil it out? 15 minutes I’d say just like ac system water is water. Any idea how much fluid you would be pulling through with a pump? Per line? It’s not sealed you say so it’s going to be more difficult to hold a vacuum? Sounds like something not to be done. Eventually it will work itself down to the bleeders and come out but likely a month later you will need to bleed again. Which will mostly take care of that...This is also why it’s either me or one other local person in this whole darn world who will touch the brakes on my vehicles. You just don’t know what the plan is. Not arguing too much with the people from the south I love the weather but wouldn’t bleeding it every couple years negate this? Here in Iowa when the crops growing we have some amazing humidity for this far north as well for about 4 months if you come here in august you will never come back but we do also get a break from it.

Eric.......And the crappy old truck will drive fine at 40 mph with out overheating the brakes. There will be corrosion, and and bad/leaking wheel cyls, and some wheels not working at all.. And the master cyl will eventually fail.. rust in the body, and low compression. Bad rotted windshield wipers. A couple of burnt out light bulbs... It will continue to stop fairly well, especially as long as the front brakes work. And then the sun will come up in the morning...

 

[Levi81]

Water doesn’t like to mix with hydraulic fluid or gear oil in the same way it does with brake fluid. Run a hydraulic system at temp long enough and water will evaporate out of it.