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So my 2006 A4 and My 2008 BMW both call out a 2-year change interval on the brake fluid. Both came with scheduled maintenance for the first 4 years, although Audi now charges extra for this service (since 2007), which is odd, since the down-market VW brand still carries it for 3 years (?!!??). Interestingly, the change interval on the VW (2010 Golf TDI) is 3 years! Have something to do with the factory maintenance being 3 years or just better fluid? Hmmm.... Last time a changed the Audi, the fluid was so clear, I couldn't tell when the old was out and the new was in. Super blue next time.
 

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Very strange, the change interval is normally 2 years. The fluid is all the same.

Super blue is a good fluid but I don't know how thin it is. The newest VW-Audi-BMW and many others now use a thinner brake fluid to work with the thin holes on stability control systems. Supposedly it makes a small difference in response.
 

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UK 2010 MY MK6 Golf brake fluid change interval as stated in the car manual is that the first change should be at 3 years and then at 2 yearly intervals after that.
 

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I think its a scam, VW is trying to get out of bleeding brakes under 3yr maintenance plan. Two year interval from day 1 is best.
 

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VW is trying to get out of bleeding brakes under 3yr maintenance plan. Two year interval from day 1 is best.
Hopefully mine will get change on its third year service, there is a sticker on the door jam probably put on when it had its PDI that says brake fluid change 3 years then every 2 years after that?
 

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Yeah, thats what they are trying to do, say that the first change should be after 3 yrs, then every 2. I mean I know many people that never change brake fluid, they just don't know that's ever supposed to be done.

Obviously you could go a long time before there is a problem, but guaranteed brake system will have major issues later on due to moisture in the system.

If they wanted to change the invterval to every 3yrs I might understand that more, then 3 and then 2. Just because something is new doesn't mean its perfect or that it will last longer.
 

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So do you all know why they recommended to change the brake fluid at yearly intervals?
 

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I assume you mean why do they recommend changing based on years and not miles?

Its because the #1 reason brake fluid needs to be replaced is because it accumulates moisture. Once the fluid accumulates moisture, the moisture begins to preforate the rubber brake lines and the seals inside the calipers, cylinders, etc. and corrode metal parts from the inside out. This is why you NEVER should use brake fluid from an open container. Anytime brake fluid needs to be changed or added it always needs to be from a brand new, fresh bottle that was sealed. If you have left over brake fluid after adding get rid of the rest unless you plan to use it within a few days.

Brake fluid hasn't changed much over recent years. Synthetic brake fluid is better but still absorbs moisture. Another reason brake fluid is changed is to remove any dirt/particles that have accumulated.

The mileage of the car is basically irrelevant between changes because the brake system is obviously hydraulic and the fluid is in-compressible, its just transmitting a force. It doesn't wear out. The rate at which the fluid absorbs moisture is constant, that's why its a yearly recommendation, not mileage.

The only thing is, that if the brakes have been overheated and the fluid has been boiled (usually causes fluid to become very dark and the calipers can be affected), this is an operating condition that is cause for a fluid change. Also, for those that are wondering, this info is not specific to VW, but does apply to our cars.
 

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Yes golfTDI1 does know.

Brake fluid is hygroscopic which means it absorbs/attracts water vapour. Now I wouldn't say it attacks the rubber components or causes corrosion in a braking system as Ethylene Glycol is added to prevent corrosion it just means it will boil at a lower temperature from 270 deg C.

If you are really serious about keeping a check on your brake fluid condition then there are brake fluid testers on the market that will test its boiling point. Now most garages will test a sample from the reservoir because its easy and convenient but the true test is a sample from the brake caliper as thats where the heat is produced. We know that the reservoirs are vented to allow fluid displacement so you will get a slight amount in there. They say that water is absorbed through the flexible brake hoses. Now you say if water can get in fluid can get out true but its very slowly absorted over a long period of time.

Now I'm not reading this of info from The Brake Fluid Tester this is something we were told when I did my technician courses 40 years ago and things haven't changed that much since, I'm showing you this link for reference?
 

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Lol, Keith I did figure that you probably knew the background on brake components but there are lots of people that don't so I figured I'd elaborate. And yes, the fluid does contain a glycol to prevent corrosion, but the glycol breaks down. Its anti-corrosive properties are reduced over the course of time. Therefore it stands that if the fluid is not replaced at regular intervals corrosion and rubber hardening will occur in the long term.
 

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OEM Fluid is the Best IMHO

The OE fluid is DOT-4, so it has the same specs regarding heat as other products, like Super Blue. OEM is cheaper, for one, and I've seen slave cylinders begin to creak with the non OE fluid - when switched back to the OEM DOT4 the squeak goes away.
 

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Well I've never heard or come across creaking/squeaking cylinders with different fluid makes?
 
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