What is the life expactancy of brake fluid

[calyx]

Is it really 2 years?
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Boris - London

[DrDonnyBrago]

[DANNYBOI]

Yes 2 years and there bringing in a tester into car mots nextyear to test it
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NSR YEHA

[Rogerborg]

[DANNYBOI]

just a we handheld machine the size of an ipod or sumit it has 3 lights same as traffic lights reds fail amber is fail/advisory its up to the tester and green is fine
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NSR YEHA

[c_dug]

Says who? Is what Mr. Rogerborg means (and I was thinking)
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I am a bellend, I am a man of constant sorrow, I am a gummy bear, I am a rock.

[Raffles]

I've been riding/driving for 34 years and I have always maintained (or paid someone else to maintain) my own vehicles. I have never periodically changed the brake fluid in any of my vehicles and I have never experienced any ill effects from my negligence to so do.
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A good loser will always be a loser.

[calyx]

[Walloper]

[Walloper]

Brake Fluuid manufacturers obviously weren't selling enough of the stuff.

Propaganda sells things.

Truthfully, nothing wrong with changine it. Nothing lasts for ever and simple measures can sometime prevent major catastrophies.
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W-ireless A-rtificial L-ifeform L-imited to O-bservation P-eacekeeping and E-fficient R-epair

[Ichy]

[neil.]

For the sake of a few pounds and an hour or so of time, you may as well flush it every 2 years. Manufacturers also recommend you replace rubber hoses and master cylinder internals every 4 years as well but that's another debate altogether...

[DANNYBOI]

i have seen it last quite a wile but at the end of the day its all down to cash i have used the brake fluid tester myself i will try to get picks for you all but im just giving you a heads up change it or dont change it its not me who will fail mot for the sake of 3 pound and a bit of time
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NSR YEHA

[DANNYBOI]

https://www.google.co.uk/images?q=brake+fluid+tester&rls=com.microsoft:en-gb:IE-SearchBox&oe=UTF-8&rlz=1I7GZAZ_en&redir_esc=&um=1&ie=UTF-8&source=og&sa=N&hl=en&tab=wi&biw=1276&bih=715
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NSR YEHA

[Robby]

Do it every 2 years. It's extremely easy to change brake fluid.

It gradually loses its effectiveness over time, and you will only notice this loss of effectiveness when you are having to work the brakes really hard and get them really hot, like on a high speed emergency stop or hard, fast ride with lots of heavy braking. So you'll have no brakes when you really need them.

The moisture absorbed also promotes corrosion. Seeing as caliper bits on bike corrode far too easily anyway, changing the brake fluid more often means stripping and cleaning the calipers less often. Stripping and cleaning the calipers is far harder than changing the fluid.

It costs a fiver for enough fluid to do a full change on a bike. Do it.

[Skudd]

[weasley]

There are the threads of truth in here, but the science is a bit mixed up.

Conventional brake fluid is made largely from a glycol-based compound - water is soluble in this compound so, over time (as described), water gets absorbed into the fluid.

The main problem this causes is a lowering of the boiling point of the fluid. This is a problem because, under use, a brake fluid can get quite hot (in/around the caliper). If the boiling point of the brake fluid is too low then the fluid will boil, thus introducing a gas into the brake system (not air or hydrogen but gaseous water). Gases are compressible whereas liquids are (effectively) not. Having a compressible gas in the fluid means that the pressure you apply at the lever/pedal goes into compressing the gas rather than moving the caliper/drum piston. Hence you get a spongy feeling and no retardation. This can be anything from annoying to lethal.

As soon as you break the seal on a bottle of brake fluid it is open to the atmosphere, which is full of water (humidity). Over time the fluid will absorb enough water to lower the boiling point enough to be dangerous. The only way to be sure of a specific system's fluid composition is to use a fluid tester (which will determine the boiling point) but since we don't all have one then the limit of 2 years is set. Given the safety implications of the braking system, this is deliberately conservative.

During a brake fluid testing programme where I work (employees were all given the chance to have the fluid in their cars checked) around 25% of cars tested had fluid in a dangerous condition. Under normal driving/riding, it won't show up as we tend not to hammer the brakes hard on the road. However, in an emergency stop you might realise, too late, that the fluid is overdue a change.

Also, once a bottle of fluid is opened, the timer is ticking - I only ever use freshly-opened brake fluid, never any that has been opened and left on a shelf in the garage.

Finally, all this is irrelevant if you use silicone fluid - this does not absorb water at all so the boiling point remains largely stable over time. However, water can still get into the system but rather than being absorbed by the fluid, it stays as free water and, being denser than the silicone fluid, tends to pool in the low points of the brake system, like the calipers. This free water can be very corrosive as well as potentially boiling when heated. You can only use silicone fluid if the seals in your brakes are compatible though, and all glycol fluid has to be completely flushed out. Silicone fluid tends to be used in racing rather than on the road.

[Paxovasa]

[Raffles]

[Paxovasa]