997S Brake Fluid colour 1.5 years since last changed???

[knightrider]

Now we all know how 911's are supposed to have their brake fluid changed during every service, but I took a look at the brake fluid in my 2006 car which was last serviced 1.5 years ago (and has done 10k miles since) and it looks fresh and clear (slightly yellow). I did this by opening the cap under the bonnet and looking directly into the hole (would the colour here be the same as the fluid running throughout the system???)

My question is brake fluid needs changing when it goes dark brown in colour, so does the fact that my fluid looks like it is nearly new mean it doesn't really need doing, apart from to keep future buyers happy that the car has 100% correct service history?

I've owned various performance motors over the years and this 2 yearly brake fluid change seems overkill for normal road use.

Nice one

 

[THX911]

Brake fluid is a Hydroscopic liquid meaning it absorbs or attracting moisture from the air.

Bet you wouldn't open that container now? [] no damage done, just change it every two years even if you have not use the car at all I'm afraid... []

 

[evansash]

I asked the same when it was last changed and about the spark plugs that needed changing after not many miles. I have Porsche warranty and was told it would be invalidated if I did not have these 2 items renewed!

 

[tscaptain]

As the fluid doesn't circulate what the fluid is like in terms of performance/integrity at the caliper end of things is going to be somewhat different to the fluid sitting in the top of the reservoir. Water can get absorbed into the fluid through rubber apparently - see this piece.

http://www.aa1car.com/library/bfluid.htm

I will be changing mine every two years because, along with tyres, the braking system seems to be a fairly important part of the car when it comes to staying alive![]

Edit - I think most, if not all, manufacturers recommend a change every two years?

 

[dereksharpuk]

A Warning.

Many years ago, in a far off land, a very young RAF officer borrowed a car for a trip up the mountain. Unknown to him, but not surprisingly, the brake fluid had not been changed for some 10 years.

On the way down the mountain, this silly man used the brakes all the time to retard the speed instead of using the gears. Just when he reached the 1:5 slope the hydraulic fluid boiled and became gas.

The pedal went to the floor, the brakes were as useful as a chocholate tea pot, and the car gathed speed reaching a terminal velocity far exceeding that possible on the flat under full power.

The fact that I am writing this gives a clue to the ending of my tale, however, it cost me a lot in laundry bills, but at least I did not have to return the car to it's owner.

Many years later, during a rather exciting and very fast drive round the Isle of Man TT in a Porsche GT3 RSR the same thing happened on the mountain circuit, but without damage occuring to the car. The wrong hydraulic fluid had been put in the car!

Lessons learnt:

1. Boiling point of water is lower than boiling point of hydraulic fluid.
2. Hydraulic fluid is hydroscopic and made be 75% water after many years.
3. Fluid will boil at a lower temperature the higher you go.
4. Put the right hydraulic fluid in the car.
5. Never drive faster than your Guardian Angel can fly!

 

[garyw]

ORIGINAL: knightrider
I've owned various performance motors over the years and this 2 yearly brake fluid change seems overkill for normal road use.

Seems a bit of an oxymoron to me.. []

Nearly all performance manufacturers say change it every 2 years!! heck even my van has it done every two years []
No compromise on tyres and brakes....

But please, do run it and let us know if were being ripped off...
A heavily worked Porsche can still cause the brake fluid to go a bit mushy.. ask Tom..

garyw

 

[knightrider]

ORIGINAL: garyw

ORIGINAL: knightrider
I've owned various performance motors over the years and this 2 yearly brake fluid change seems overkill for normal road use.

Seems a bit of an oxymoron to me.. []

Nearly all performance manufacturers say change it every 2 years!! heck even my van has it done every two years []
No compromise on tyres and brakes....

But please, do run it and let us know if were being ripped off...
A heavily worked Porsche can still cause the brake fluid to go a bit mushy.. ask Tom..

garyw

Last car was a e46 M3 and that had recommended change of brake fluid change every 4 YEARS. Get your facts straight pal before being sarcastic!

 

[tscaptain]

ORIGINAL: knightrider

ORIGINAL: garyw

Nearly all performance manufacturers say change it every 2 years

garyw

Last car was a e46 M3 and that had recommended change of brake fluid change every 4 YEARS. Get your facts straight pal before being sarcastic!

Nearly all but not BMW then! It would still seem that the accepted wisdom around the various forums and elsewhere on the internet is that 2 years is a sensible interval for all but certain manufacturers have chosen a longer interval for reasons that are unclear.

 

[dereksharpuk]

ORIGINAL: tscaptain

Nearly all but not BMW then!  It would still seem that the accepted wisdom around the various forums and elsewhere on the internet is that 2 years is a sensible interval for all but certain manufacturers have chosen a longer interval for reasons that are unclear.

Perhaps for the same reason some cars have much longer service intervals than others. I gather Lincoln specify 100,000 miles per oil change. It's not all down to physical aspects; some is down to marketting.

 

[minny]

The dry boiling point of fresh DOT4 brake fluid varies between 180 - 210 degrees celcius depending on brands. Obviously depending on use and atmospheric conditions, it can absorb moisture at different rates but cars used less seem to absorb more. By using a brake fluid tester to test the fluid (the type that boils a sampple of brake fluid e.g ALBA ALB1000), after 2 years this can drop to 140-160 degrees. Whether this is enough to justify changing the fluid is obviously up to the owner but for £20 for 3 litres and a quick DIY, it is a fairly cheap form of insurance for 2 years. A lot of others would spend 10x that on wax for the bodywork. The moisture in the fluid can also corrode the steel pistons in the calipers.

 

[garyw]

ORIGINAL: knight rider
Last car was a e46 M3 and that had recommended change of brake fluid change every 4 YEARS. Get your facts straight pal before being sarcastic!

Having also owned a BMW that was recommended brake fluid changes at 2 years [&:] I do believe I have my facts quite straight thank you.
I'm more concerned on the Performance car and not wanting the brakes to be as good as possible...

garyw

 

[vitesse]

One can be cynical & given the advances in all technology,think that there is more about Dealers getting extra business than whether in a car used just on the road that the fluid does need changing that often-I have Dot 5 in my BMW-I suggest less likely to absorb moisture than lower grades & my pedal stays very firm despite hauling nearly 2 tonnes fully laden to a halt everytime I have to stop-I admit to having trained myself to left foot brake & change down using the steptronic element of the autobox but I refrain from downchanging just for braking purposes these days,so the brakes do get a hard time as one can easily judge from the dust on the front wheels.
Different on a competition car or trackdays/sprints of course.

 

[jonathanw]

I am not sure I like the "pal" etc references - seems to me a bit patronising.

If you dont want to change the brake fluid then as they say "its your funeral". I can understand penny pinching over safety if your running a banger and on a very tight budget but those of us who are fortunate to own these wonderful cars should surely be able to splash out on a brake fluid change every few years. I dont beleive there can be any compromise when safety is at risk - but there again I am a doctor!

 

[knightrider]

ORIGINAL: jonathanw

I am not sure I like the "pal" etc references - seems to me a bit patronising.

If you dont want to change the brake fluid then as they say "its your funeral". I can understand penny pinching over safety if your running a banger and on a very tight budget but those of us who are fortunate to own these wonderful cars should surely be able to splash out on a brake fluid change every few years. I dont beleive there can be any compromise when safety is at risk - but there again I am a doctor!

There is no reason why 2 or 3 year old brake fluid should ever even come close to hitting its reduced boiling point during normal road usage. Having said that I will just change the damn fluid anyway just to keep the service book properly stamped up. Personally I know it doesn't need changing - why, because my last car being a e46 m3 never had a single brake fluid change (recorded) and it was 8 years old when I sold it. I also gave it the beans regularly and never had any issues braking.

 

[Rodney Naghar]

If your question is will brake fluid last longer than 2 years ona road car - yes it most likely will. It won't necessarily turn brown before it goes off though (my friend's Ferrari didn't have a brake fluid change for 4 years but it went off on track looking milky white)

Likewise, your car won't implode if you don't service it on time. You can get away with not servicing your car for many years, not changing anything or doing anything until something breaks -you can say I told you so, and have a big wedge of cash left in your pocket.

However when it comes to selling your car, scrimping on important things like a brake fluid change (which goes in the service book) is not going to look good, because it's not really much to spend. So are you really saving money?

 

[garyw]

Knightrider, seriously- drop the attitude.

You asked for advice and have been freely given it on more than one occasion.
You may well know better and well done on the BMW lasting 8 years.

The M3 including the CSL was known for its brakes- and not in the best of light as it was one of the first upgrades most people did.
The fluid change can and does make a difference to the pedal feel under continous/heavy braking and trackday use to a Porsche.

garyw

 

[tscaptain]

ORIGINAL: knightrider
. Personally I know it doesn't need changing - .

Er, why did you bother asking for for opinion then? Seven or so posts here suggest that it may be a good idea. It may be a ploy by the manufacturer/dealer network to extract more dosh from our wallets - or maybe not. Either way given the overall cost of running these cars it seems a splash in the ocean and not an area of maintenance that I would wish to risk ignoring for the sake of the saving involved. Hey ho![]

 

[unclewinks]

Well said all,Good show lads[]

 

[jonathanw]

Gary

I saw knightriders unedited reply to my post and I think he should go back to BMWs as they are more his style.

Why ask for advice and be ungracious about what is suggested.

From a "real chap" as our pal knightrider called me.

I think this thread should be brought to an abrupt stop. Gary over to you.

 

[jpbecker]

Guys, I'm a professional Aerospace Engineer and offer my three pennies worth; the brake fluid in our cars is fully synthetic which by its properties isn't hydroscopic. But I guess you could say that debris etc will eventually contaminate the fluid but I wouldn't have thought this would necessitate a change every two years. However, I would always follow the manufactureres guidelines as it depends on the test conditions, failure rates etc. But it has always intrigues me why the intervals are so regular!