Break Fluid??!

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My old car calls for DOT 4; I was wondering how important is the replacement for you and how many of you keep up with maintenance of the fluid;

On the note, I replaced mine today after many, many miles, and little or if any difference in braking power IMO

 
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I have been saying it for years (but no one will listen) that a well designed brake system will keep the fluid dry. Furthermore, even if water gets in the fluid, unless your in the mountains or towing, your not going to boil the fluid. I never bleed my brakes yet have never replaced a caliper. Go figure.
 
It's important and I keep up with replacement.

I was a mechanic at a Honda dealer eons ago before more education and eventually becoming a UPS semi mechanic.
Don't be disappointed your brakes don't feel better. I've worked on my share of vehicles where the brake fluid was never changed and caused expensive repairs.
Brake fluid accumulates moisture over time. Brake fluid is cheap. Replacing an ABS pump is not. Losing your brakes away from home is no fun either.
 
Originally Posted By: philipp10
I have been saying it for years (but no one will listen) that a well designed brake system will keep the fluid dry. Furthermore, even if water gets in the fluid, unless your in the mountains or towing, your not going to boil the fluid. I never bleed my brakes yet have never replaced a caliper. Go figure.


Explain how brake fluid gets dark over time.
 
Originally Posted By: philipp10
I have been saying it for years (but no one will listen) that a well designed brake system will keep the fluid dry. Furthermore, even if water gets in the fluid, unless your in the mountains or towing, your not going to boil the fluid. I never bleed my brakes yet have never replaced a caliper. Go figure.

If you keep your car for only a few years this is correct. Why change it? If you keep it for a long time, change it regularly. Your brake system corrodes from within and you can’t see it and one day it will fail you. Mine did and luckily I was in a parking lot. I would have been in deep kimchi had I been on the highway.
 
It's just like any other fluid. It degrades and gets contaminated over time. Just change it and feel good about it.
BTW: It gets dark from the rubber lines.
 
Originally Posted By: miden851
My old car calls for DOT 4; I was wondering how important is the replacement for you and how many of you keep up with maintenance of the fluid;

On the note, I replaced mine today after many, many miles, and little or if any difference in braking power IMO





You won't notice any difference in "braking power" (whatever that is meant to mean). As long as the brake fluid is a liquid, it'll work right up until it isn't.

Then it won't.

Water would work as a brake fluid, until it didn't

If (as is likely) old brake fluid caused corrosion in the system, you MIGHT notice some deterioration in function (sticking pistons, for example) prior to (possibly catastophic) failure.
 
Brake fluid is hygroscopic and absorbs water from the air and once absorbed, it cannot be separated. I change mine every 3-4 years, not a major expense and it keeps the system fresh and working well.
 
Originally Posted By: 2015_PSD
Brake fluid is hygroscopic and absorbs water from the air and once absorbed, it cannot be separated. I change mine every 3-4 years, not a major expense and it keeps the system fresh and working well.

Right. I do about 2 years which might be overly cautious but I like to keep it fresh.
 
Originally Posted By: E150GT
Originally Posted By: philipp10
I have been saying it for years (but no one will listen) that a well designed brake system will keep the fluid dry. Furthermore, even if water gets in the fluid, unless your in the mountains or towing, your not going to boil the fluid. I never bleed my brakes yet have never replaced a caliper. Go figure.

If you keep your car for only a few years this is correct. Why change it? If you keep it for a long time, change it regularly. Your brake system corrodes from within and you can’t see it and one day it will fail you. Mine did and luckily I was in a parking lot. I would have been in deep kimchi had I been on the highway.


I have always drove my cars 12-14 years....
 
Thank you for all your suggestions and experiences!

Mine got cloudy for sure; I think i haven’t change it in 5 years or approximately 80-100 miles; it took me more than I expected honestly; I haven’t stop bleeding until I’ve seen clear fluid on the other end; I have bled about 1/2l of fluid; next time I’ll change it sooner for sure:

Also how about shelf life of the fluid that is opened now; how long it is reasonable to keep it around as an open bottle please?
 
Brake fluid flushing is done by less than 10% of North American drivers, based on my seat-of-the-pants research. I've done it for the last 25 years, every 24-30 months & I've never had a ABS system failure, ever. Is it overkill to do this service? if you never tow a trailer, never drive in the mountains, never keep your cars over 10 years, never give your old cars to family members, it might be a waste of time & money. Otherwise it doesn't cost much and is in the spirit of all things BITOG.
 
Originally Posted By: philipp10
Originally Posted By: E150GT
Originally Posted By: philipp10
I have been saying it for years (but no one will listen) that a well designed brake system will keep the fluid dry. Furthermore, even if water gets in the fluid, unless your in the mountains or towing, your not going to boil the fluid. I never bleed my brakes yet have never replaced a caliper. Go figure.

If you keep your car for only a few years this is correct. Why change it? If you keep it for a long time, change it regularly. Your brake system corrodes from within and you can’t see it and one day it will fail you. Mine did and luckily I was in a parking lot. I would have been in deep kimchi had I been on the highway.


I have always drove my cars 12-14 years....

mine failed at 21 years of age. When I finally did the brake flush after replacing brake lines the fluid looked like coffee or coke and had chunks in it.
 
Originally Posted By: KGMtech
Brake fluid flushing is done by less than 10% of North American drivers, based on my seat-of-the-pants research. I've done it for the last 25 years, every 24-30 months & I've never had a ABS system failure, ever. Is it overkill to do this service? if you never tow a trailer, never drive in the mountains, never keep your cars over 10 years, never give your old cars to family members, it might be a waste of time & money. Otherwise it doesn't cost much and is in the spirit of all things BITOG.


Ancedotal. Who ever has ABS system failures? I have never seen nor heard of one.
 
Originally Posted By: E150GT
Originally Posted By: philipp10
I have been saying it for years (but no one will listen) that a well designed brake system will keep the fluid dry. Furthermore, even if water gets in the fluid, unless your in the mountains or towing, your not going to boil the fluid. I never bleed my brakes yet have never replaced a caliper. Go figure.

If you keep your car for only a few years this is correct. Why change it? If you keep it for a long time, change it regularly. Your brake system corrodes from within and you can’t see it and one day it will fail you. Mine did and luckily I was in a parking lot. I would have been in deep kimchi had I been on the highway.


Technically not correct. Brake fluid will absorb moisture from the air and that's from when they heat up and cool down. So moisture gets in through the brake lines and through the rubber from the calipers. OP won't notice any difference in braking between Dot 3 and Dot 4 as they're both liquids. The difference is in the spec, Dot 4 has a higher boiling point than Dot 3, but if the brakes never get near that temperature, then it doesn't matter. Mercedes tends to use a Dot 4+ fluid and they require brake bleeds every 2 years as Dot 4 is more hygroscopic than Dot 3. What happens is that if you don't bleed the brakes, you end up with the wet boiling temperature spec instead of dry boiling temperature. For instance my Pentosin super dot 4 has a dry boiling temp of 509 but the wet boiling temp is 329. So if you don't hit 329, your brakes will be fine even if you don't flush them and they're filled with water, but if you're towing or coming down a mountain and heat up the brakes, they may disappear when the liquid turns into a gas. Dot 3 has lower numbers, 401 dry and 284 wet.
 
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