If you boil your brake fluid should you change it?

[Scoobman]

Quick question

I have lost my brakes a couple of times after the fluid has got too hot.

Should you change it after this occurs.

Does the fluid once cooled return to the same state it was before or does cooking it degrade its state?

Thanks

[thinfourth2]

if its boiled its probably got water in it

Change it

[rovermorris999]

Was this on a track? In normal but hard road use this would suggest old fluid which will have absorbed some water. If on a track and the fluid is recent, you need a better spec fluid.

[SteveS Cup]

Are you sure you're boiling the fluid and not just experiencing brake fade?

[wackojacko]

Shouldn't be able to boil suitable and fresh brake fluid.


It would have moisture in it, usually try and change it once a year....

[Scoobman]

Thanks all - will change it ASAP
(Need to sort out some brake cooling as well)

[Fleckers]

sounds trackyday to me

change it
fit better pads
fit vented/groved/drilled pades
fit ducking from front of car to brake area
learn to drive in a different manner to stop the excessive brake uage

[pacman1]

SteveS Cup said:

Are you sure you're boiling the fluid and not just experiencing brake fade?

Ain't that one and the same?

[Hitler Hadrump]

You can buy a little pen thing to test the water content of your brake fluid, but it's probably just cheaper to change it.

If in doubt, flush it out!

[eldar]

pacman1 said:

Ain't that one and the same?

Think so, the fluid boils, creating vapour which is compressible, so the pedal travel increases.

[skinley]

pacman1 said:

Ain't that one and the same?

There are several things which can cause brake fade, boiling fluid is one of them but brake fade doesn't necessarily mean boiled fluid.

[Rich1973]

As I understand it, brake fade is when the contact areas of the pad and disc become so hot as to no longer provide suitable friction. The pedal should still be firm but give little by way of retardation. If the fluid has become so hot as to fail then the pedal will have much more travel to it. Do you know which one it is?

[Nick3point2]

Nope, heating brake fluid will boil off any water and make it better. It's an old trick for improving existing brake fluid instead of changing it (in places like Cuba where automotive supplies are hugely restricted). Pour it in a pan, bring it to the boil, put back in car.

[Ozzie Osmond]

Vapour in the system, whether from "boiling" or otherwise, is the clearest possible indication of a fundamental problem with your brake system. At the very least you need a fluid change and I suggest a long, hard look at your car and the way you are using it. Could be a classic case of "I fitted harder pads and....."

[kambites]

As above, I don't think boiling the fluid will have done it any harm but if you did manage to do so, it's probably indicative of the fluid already being past its best and/or not good enough for the car/driving.

I'd change it.

[SteveS Cup]

Brake fade is normally excessive heat from the discs and pads causing gasses in-between the pad and disc. Hence why grooved, drilled discs are considered an upgrade as it gives the gasses somewhere to escape.

That is my understanding of it anyway!!

[McSam]

Nick3point2 said:

Nope, heating brake fluid will boil off any water and make it better. It's an old trick for improving existing brake fluid instead of changing it (in places like Cuba where automotive supplies are hugely restricted). Pour it in a pan, bring it to the boil, put back in car.

Yeah - but not while it's still in the system, surely, since the water has nowhere to boil to?

As said, you shouldn't be able to boil it, but do make sure it wasn't just very hot pads/discs. The above comparisons of pedal feel are good

[snowdude2910]

Ozzie Osmond said:

Vapour in the system, whether from "boiling" or otherwise, is the clearest possible indication of a fundamental problem with your brake system. At the very least you need a fluid change and I suggest a long, hard look at your car and the way you are using it. Could be a classic case of "I fitted harder pads and....."

I was under the impression all brake fluid absorbs water over time weather it be driven hard or not and that is why it should be replaced at time intervals as it isn't a consumable so otherwise you wouldn't have to change it

[littleredrooster]

Just to summarise the above (and dispel the usual bks in a thread):

If the fluid has boiled it will let the pedal go to the floor and cannot be 'pumped back'. Brake fluid replacement is necessary and urgently required. I've never suffered this.

If brake fade has occurred, there will still be a 'pedal', but it will feel like pressing polished wood on to the tyres; no discernible retardation, but a fairly solid-feeling pedal. This is caused by the bonding agents in the pads (resins) overheating and releasing gasses which stop the proper pad-to-disc contact. No immediate cure except for different pads and/or drilled/grooved discs, or revision of driving style.

HTH