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I have a 2005 Honda Element. The owners manual states the brake fluid should be "replaced" every 3 years.

When I asked the dealer to replace the brake fluid, they said it was going to cost $190. I told them last time they did it, it was only $27. They said it was expensive because they were going to hook it up to a sort of dialysis machine to "flush" it out. The owners manual doesn't say anything about this. I can see where flushing could be helpful, but is it really necessary? If so, how often should it be done?

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  • I also have a 2005 Element and had its first brake fluid change at 149k miles. I did it at the Brake Masters for $60(with -$10 coupon). They use a vacuum pump and took about an hour. The brake feels about the same after, but the fluid is now light amber. Don't worry about not using the "Honda HD DOT3". All DOT3/4/5 are mandated by DOT to meet the boiling point requirement.
    – Noseefood
    Nov 9 '16 at 1:02
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    DOT5 has a different base than 3 or 4 and is incompatible with DOT 3 and 4 systems.. Nov 9 '16 at 6:12
  • Brake fluid(at least the not silicon ones) are hygroscopic. That means that they absorb water over time, and water boils at 100C. Your brakes and brake fluid can get much hotter than that, causing the water in the fluid to boil and create vapour locks and other nasty things. Reason to change it every now and then.
    – Bart
    Nov 9 '16 at 9:29
  • @DucatiKiller this is true, but doesn't contradict the statement that DOT 3/4/5 fluids must meet minimum requirements. Mixing them would be bad, but that's a different issue.
    – barbecue
    Dec 23 '16 at 22:27
  • My mechanic a reputable one said his wife's Subaru has 300K+ miles on it and never once did a brake flush. I did it once at the Subaru dealership and learned quite quickly most of the stuff they try to sell you is not necessary and double the price of everywhere else. Be aware. I saw a gentleman in there once who like me was quoted double the price of a brake job. I gave him the name of my mechanic who has been in the business for years. Dealerships have high overheads.
    – Donna
    Nov 11 '18 at 2:41
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When you replace brake fluid you are "flushing" the system. The way you do it, all old break fluid will be removed and new fluid in its place.

You should do this as your owner's manual prescribes. I believe normal intervals are either two or three years as your manual says. Some manufacturers may have something else, so start there first. The reason for this is that brake fluid absorbs water over time. When fresh fluid is in the system, the fluid is in a dry state. When it gets old and absorbs water, it is in a "wet" state. Depending on the fluid you are using (usually DOT3 or DOT4), as brake fluid becomes wet, it will boil at a lower temperature. This becomes important, because as you use the brakes, the fluid gains temperature due to friction of the brakes and such. As the fluid gets older, it has the propensity to boil easier, which will cause bubbles in your brake lines. These bubbles will compress where the liquid will not, thus reducing the effectiveness of your braking system.

To change the brake fluid, you start by bleeding the brakes at the furthest point away from the master cylinder. In left hand drive cars (US), start at the bake right. For you peoples across the pond, I suspect your master cylinder is on the right side of the car, so start with the back left. Then go to the opposite side and do the other rear brake. Then move to the front on the side you started with. On four wheel vehicles you only have on wheel left. When you are done with all four wheels using this method, all old brake fluid will have been changed. This can be accomplished using a power bleeder, or the old have a friend pump the brakes for you.

In my opinion, the brake fluid is one of the most overlooked maintenance items in your vehicle. People just don't think about it unless there is a leak.

EDIT (to answer your edit):

It seems the general rule of thumb for replacement is recommended at two years. You can tell how your own brake fluid is doing by shining a flashlight through the liquid (easy on a white plastic type master cylinder ... take the top off on older metal reservoirs and shine the flashlight down into the liquid). When brake fluid is new, it has a very light amber color to it. As it gets to the point of needing changed, it becomes a darker amber color. It may even get to the point where it is dark brown or even black.

As for the price you were quoted, my first rule of thumb is ... stay away from dealerships for regular maintenance items (like oil changes, radiator flushes, brake fluid replacement, etc) unless you get free scheduled maintenance from them. This is just my opinion, but my experience tells me dealerships overcharge on these types items. Chain stores are not going to be much better as far as cost and they tend to try and do add-on items (ie: you go in for an oil change and they tell you you need to have x, y, and z done as well). Find a smaller local maintenance shop you can trust (usually found through word of mouth) and use them. Your cost is going to usually be the best at these locations. Mind you, there are always going to be deals to be had, keep on the look out for these from your dealerships. Other than cost, there is usually no problems using a dealership, so please do not misunderstand. In the US, there is no requirement to have maintenance items accomplished at a dealership to maintain your warranty. (I'm not sure about the legality of this in other countries.)

About the dealership, you said "they were going to hook it up to a sort of dialysis machine to "flush" it out." This cracks me up because this is normal operating procedure for a single mechanic (without help) to perform this service. It actually makes it easier, quicker, and cheaper (less man hours) for them and they want to charge more for it. It appears by quite a bit, actually. I cannot tell you what the price would be, but shop around a little bit and you are probably going to find a better price.

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  • Thank you so much. I edited my question to be more clear about what I mean about "flushing", as the dealer put it.
    – kwahn
    Feb 4 '14 at 3:42
  • At least the Toyota dealership in Finland has quite acceptable prices for regular services. So, I don't see any reason to shop around. I do know that for some different car brands, the dealership can actually be a stealership, in which case shopping around for minor maintenance is advised. Of course, any big car specific repairs should be done by those who know the car best.
    – juhist
    Jul 13 '17 at 12:22
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NOBODY - ABSOLUTELY NO ONE - has ever documented or substantiated this malarkey about brake fluid boiling, "absorbing water over time" (how much time in that 'time' relates to specific unit(s) of measurement?), any other of the skewed mentions of the last 5 years. Power steering fluid boiling over?

Where is the water coming from? Line leaks? The braking system, from the reservoir through the lines and fittings, is a 'closed system'! Water absorbed, if ever any amount, would indicate a break/crack/split along the lineage of the system. Such faults are reparable at which time a power flush would be accomplished prior to fluid replacement.

The same goes for power steering systems - they are 'closed systems' too!

The flush and fill scams by dealers are in the majority pulled off in dealings with women (usually alone, both young or old). I challenged a "Service Supervisor" recently at a Hyundai dealership when he handed a lady a print out with "needs" indicated. Both brake and power steering flushes were cited. The lady's car had new brakes installed 6 months prior.

When dealing with the dealers, you're dealing with the enemy, especially if you're female and alone.

It's like the oil change myth of 3000 miles: not necessary except to enhance the oil industry revenue income flow.

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    While you may have a point that the importance of regular brake system flushes is exaggerated, that does not mean that brake fluid cannot deteriorate and absorb moisture. These things do happen. Brake systems are "closed systems" in the general sense, but claiming that nothing can get in or out is extreme. Brake systems have joints and rubber seals. These can allow small amounts of both air and fluids to pass through. Small leaks can and do occur. Temperature changes, weather conditions, and age of the system all play a role. Rubber deteriorates and releases chemicals into the fluid.
    – barbecue
    Dec 23 '16 at 21:58
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There is really almost no way for a brake system or power steering system to abosorb water as you describe. Leaks in lines or seals result in brake/steering fluid leaking out of the system rather than air or water infiltrating those systems as they are usually (power steering) or often (brakes)under pressure. The only way for H2O to get in is through frequent removal of the fill caps.

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    Welcome to the site. Brake fluid is hygroscopic so it has a tendency to absorb moisture over time and the seals aren't perfect. So even if the reservoir cap is never opened moisture ingression can and does slowly occur.
    – Zaid
    Jul 13 '17 at 7:32

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