Brake Fluids

[My_Yeti]

I seem to remember that the newer Yeti benefits from 3 years brake fluid change, rather than 2 in my case (10 reg).

I am wondering if that is to do with the fluid or the system?

The reason I am asking is when do it needs to be changed next? at 4 years old or 5?

[Llanigraham]

My dealer now says it is 3 years across the board, so 3, 6, 9 etc.

[Yeti_Man]

Ive just had my fluid changed at the two year service and although it's just about noticeable on the road, I'd say that it could have safely been done in another 12 months time on my car. My book said two yearly changes hence that's what I did. :-)

[My_Yeti]

Thanks for the replies. I understand that it may last for another year, however I am more concerned about the warranty of not having it changed at the advised schedule. Mine was registered on April 2010 and the service book recommends every 2 years.

Surely, it's the different brake fluid and not a system/cap change that allow the fluid to last longer.

[Freshacre]

Me too. April 2010. Booked in tomorrow 40000 mile service at Sinclair, and brake fluid replacement as advised. Also Summer tyres back on and winter Contis stored

[My_Yeti]

They have put a note on the service booking, will show them my service booklet when I turn up on Monday.

[Llanigraham]

Surely, it's the different brake fluid and not a system/cap change that allow the fluid to last longer.

Is it a different fluid?

As far as I can tell it is Dot 4 or 5.1, which is fairly uniform across lots of vehicles, and that hasn't changed for more than 4 years.

The only major change would be to silicone fliud (DOT 5) and I don't know of any major manufacturer who has gone down that road.

[JCP]

A big organisation like VAG will vary service requirements as experience suggests-and, if they can, to lower the pence per mile for the bean counters/fleet salesmen.

Brake fluid hasn't changed nor has the hardware. They must have figured they could get another year safely.

I did read that FocusZetec found his fluid change noticeable. That is a bad thing-you shouldn't want to drive a car with brakes which aren't up to scratch.

2 years is soonish to change fluid but if it does make a difference why wouldn't you?

[Yeti_Man]

I did read that FocusZetec found his fluid change noticeable. That is a bad thing-you shouldn't want to drive a car with brakes which aren't up to scratch.

2 years is soonish to change fluid but if it does make a difference why wouldn't you?

I said 'just about noticeable'; specifically, the brake pedal was just a little firmer. In terms of performance, use and mileage, im pretty sure mine would have still been safe 12 months from now. :-) I'm sure the change is either to benefit the dealers or done originally to make the total cost of ownership appear lower on the servicing front.

[My_Yeti]

Will update on my dealer's position when I take it in on Monday.

[r999]

I said 'just about noticeable'; specifically, the brake pedal was just a little firmer.

Interesting but puzzling. Water (which is what contamines brake fluid, since it is hygroscopic) is every bit as incompressible as brake fluid itself - until it boils, of course. So unless one starts using the brakes so hard as to get the fluid near to boiling (i.e. terminal fade), it would seem no difference in pedal firmness should be apparent between clean brake fluid and old stuff, or indeed plain water.

I had brake fluid changed on Saturday after 3 years, one year beyond spec (not in a Yeti). No perceptible difference in the pedal whatsoever.

[Yeti_Man]

Interesting but puzzling. Water (which is what contamines brake fluid, since it is hygroscopic) is every bit as incompressible as brake fluid itself - until it boils, of course. So unless one starts using the brakes so hard as to get the fluid near to boiling (i.e. terminal fade), it would seem no difference in pedal firmness should be apparent between clean brake fluid and old stuff, or indeed plain water.

[looby]

It is vital to have the brake fluid changed as per Dealer Service schedule, VAG says every two years. Failing to adhere to this can lead to failure of the ABS system which could incur a cost of circa £1500. no joke....

[Freshacre]

It is vital to have the brake fluid changed as per Dealer Service schedule, VAG says every two years. Failing to adhere to this can lead to failure of the ABS system which could incur a cost of circa £1500. no joke....

Explain - please!!!

As an old fuddy-duddy who isn't up with stuff, I don't understand why... ... ....

please.......

pretty please........

[Merlinman]

Looby - go check a current Yeti or indeed any VAG handbook - first brake fluid change is now at 3 years and then every 2 years thereafter.

[Yeti_Man]

It is vital to have the brake fluid changed as per Dealer Service schedule, VAG says every two years.

No they dont, thats the whole point of the OP's question. Id say its the same stuff for sure but they just adapted the timeline for change for one reason or another.

[speedsport]

Explain - please!!!

As an old fuddy-duddy who isn't up with stuff, I don't understand why... ... ....

please.......

pretty please........

This is nothing new, in fact it is actually less of a problem than it was in cars 40+ years ago thanks to improvements in brake fluid (which can stand higher temperatures) and to brakes themselves. But it is still potentially serious and for a £35 fluid change, you are lessening the risk of brake failure or expensive component replacement later.

The problem: Brake fluid absorbs moisture (ie water) over time. This is called being hygroscopic. This causes two issues:

1. The water content will cause the inside of brake cylinders & master cylinder/servo to corrode. This will ultimately lead to failure as components seize. It is not just the ABS system that fails, it can be any moving components within the braking system with contact with brake fluid.

2. Water boils at a far lower temperature than brake fluid. So, when the fluid gets hot (after prolonged or frequent brake applications) the water content will boil. Boiling water turns to gas and unlike a liquid, a gas can be compressed which means that when you press the brake pedal, that effort is absorbed by the gas and the pistons in the cylinders don't move. This results in a loss brake efficiency or in its worse case, total brake failure.

It has always been a recommendation that brake fluid is changed periodically. With ever more complicated brake systems, it make sense to have it changed as recommended rather than risk a far bigger bill later. Also, complying with the manufacturer's specified service schedule may result in them taking a more sympathetic view if something goes wrong out of warranty.

However, I must admit that I don't understand why the first change is now 3 years (when it was two) and why subsequent changes then revert to two years.

Hope this helps

Edited 13 April, 2012 by speedsport

[yetiscot]

[Tech1e]

No they dont, thats the whole point of the OP's question. Id say its the same stuff for sure but they just adapted the timeline for change for one reason or another.

Adapted the time so the two year service plans no longer include a brake fluid change.

[Llanigraham]

People, Tech1e knows what he is talking about, as he works at a dealers, so please accept his word!!

[Tech1e]

Ha ha, that's not official it's just what I reckon. VW did the same in 2008, introduced 2 years service plans then bumped the BFC to three years so they didn't have to pay for it.

[My_Yeti]

I just bought my service plan and since it is going to cover 2nd and 3rd service, they would have to change the brake fluid nonetheless.

[My_Yeti]

They changed mine at 2 years because mine is the older version.

I can actually tell the difference, towards the end of the first two years, the brake paddle was getting much more spongee and it is much sharper now (not noticeable at slow speed though).

[bahnstormer vrs]

However, I must admit that I don't understand why the first change is now 3 years (when it was two) and why subsequent changes then revert to two years.

Hope this helps

... another small saving to keep the SMR cost for the 1st three years of a car's life down?

On a related issue, which is hopefully not too far off topic, I've been puzzled for a couple of years (since it occurred) with my Octavia being run on the 'variable' service regime that the first two services were 18,600 miles apart but the 3rd Service came up only 14,500 miles later without any particular change to my daily driving pattern or style.

My puzzlement extended to thinking of attempts at keeping the servicing costs down in the early years of a car's life, but this not being so important later on.