Perhaps someone can provide the typical cost for a brake fluid change and flush.

Thanks in advance.

 

DIY?

$20.

 

A quart of regular DOT4 is maybe $8-10, going with excellent stuff, probably no better, cost me @$21 shipped from Amazon. I have a brake fluid pump so the job can be done alone very quickly with no mess otherwise you'll need someone to pump your brakes. One quart is all you need

Total time probably an hour most of that is due to having up each wheel... and while they're off clean them inside and out

https://www.amazon.com/gp/aw/d/B003VXRPL0/ref=mp_s_a_1_2?ie=UTF8&qid=1471238320&sr=8-2&pi=SY200_QL40&keywords=brake+fluid+dot+4&dpPl=1& dpID=51l7pAkzk0L&ref=plSrch

 

An Indie shop should be around $69

 

For a dealer anywhere from $80 to $150. Certainly an indie can handle this very easily for much less.

 

Has anyone here done a reverse flush?
That's the easiest way apparently to do it right.

 

I haven't even heard of that but it wounds rather counter-intuitive to me. The fluid at the master cylinder is usually clean looking whereas the fluid at the brake caliper is darkened (due to heat and such) therefore I'd prefer not to put this compromised fluid back through my system and through my master cylinder. I want to have clean/fresh fluid throughout my system, forcing it through the master cylinder down to the bleed screw on the caliper just makes sense to me. Using the pressure system I bought for @$50 has worked awesome on everything except my Honda (Honda is the only mfg that has a very unique cap on the master cylinder so nothing else fits).

There's been a number of lube shops that have been nailed for selling services that were not performed, the two top ones are transmission services and brake fluid changes. In the case of the brake fluid services/changes the shops only suctioned out the fluid in the master cylinder then refilled it leaving the fluid in the lines alone (do a search on YouTube to see many of the videos and stories). Looks perfect but has done nothing to help you as the owner. The only way you would know is by checking out the bleed valve fitting to see if they even touched it, and if you are doing that then why not spend the extra 15 mins and do the job yourself as you've done the hardest part of the service.

 

Brake fluid is hygroscopic, so moisture is typically absorbed through the cap on the master cylinder, not the other way around. The fluid darkens as it absorbs moisture.

 

Interesting to read the technique. I have been flushing from the master down to the bleed screw for 30 years without an issue. Funny that some folks online are saying that is the wrong way, mostly those that are trying to sell reverse bleeding apparatus.

Since a brake flush is a very low cost, low time, and only done every 2 years so not worth a change in method. Plus I have a buddy with a vacuum pump so it is really easy!

 

What I have been told the race guys do is suck up fresh fluid from all 4 bleeder valves simultaneously.

I think I understand the argument, if you push fluid by opening one valve at a time, you are not exactly getting 100 fresh fluid in that line, there will always be some cross-contamination, heck for one you could never have just fresh fluid in the master. So one method pushes somewhat fresh fluid, and the other 100% fresh.

Is brake fluid contaminated by small percentages of the old fluid?

 

Q&C, first its good to see you back sir!

As to your mention that by using the method of opening one valve at a time not getting all the fluid out what do you mean by this? I've been using this method for years starting of course by the farthest valve first working towards the closest to the MC so I'm confused as to why you feel that would leave any older/compromised fluid in the system. Perhaps it could come down to the same argument that unless you fully flush your engine, oil pan, etc that you're not getting ALL the older oil out of your car but curious as to your train of thought here

 

It depends on the type of brake fluid being used. Most brake fluid is hygroscopic, but DOT-5 is hydrophobic used mainly for high-temperature applications, but is not compatible with DOT-3 or DOT-4 fluids and does not work with ABS.

Brake fluid generally is contaminated by water vapour and is required by specification to darken indicating it is contaminated. Water effectively lowers the boiling point of the fluid thus affecting brake performance.

 

NBC - There's no mention of using DOT5, not recommended in our manuals, previous posts, or anyone questioning that not sure why that was brought up here.

Contrary to your claim in this last post and previous post as to the reason for brake fluid turning colors you state it is due to water contamination through the master cylinder cap... I find it quite hard to believe your theory that water permeates through that thick plastic nor the rubber seal under the cap, that's a sealed system by design. That concept of the color changing due to water contamination also seems to fly in the face of most every site which the majority say the color changes due to either heat being applied and/or other contaminants being introduced into the system, or mostly simply due to the rubber lines running the length of the car bleeding the color into the fluid. I'll go pour some water into the last few ounces of my DOT4 fluid sitting on my shelf if that will make you feel better and we can see if it changes colors. When I change my fluid I do so from the caliper fitting, and when the fluid starts to come out it is black in color, according to your claim water is at the bleed valve... not buying that water is there and that has caused the color change. Happy to provide links for the above if you care...

 

Howdy Pilgrim,

When you bleed at caliper, the process is you are constantly adding new fluid to old in MC, because you never want the MC to go dry. Thereby the fluid will always be a blend. When you do the inverse, two things are happening different. The fluid in the line is 100% virgin, and what dilution remains is at the reservoir, not caliper as in the original system.

I am merely making their case I really dont have a favorite yet. I too have been changing brake fluid for donkey's years and only recently have heard this stuff where they recommend changing the brake fluid more often than some oil changes.

 

The fluid specification calls for it to darken when contaminated by water vapour. That is a fact that no one is asking you to 'buy'. The U.S. DoT requires that all automotive brake fluid be amber in colour and to darken when moisture is present. This is the reason Teves were required to stop marketing and selling their 'Super Blue' Racing Brake Fluid in the U.S.

On the contrary, the master cylinder cap is not completely sealed as you claim; it must allow air to enter for the fluid level to drop when caused by brake pad wear otherwise a vacuum would be created causing the reservoir to collapse.

Once moisture enters the system, it causes the fluid to begin to darken, including the fluid in other parts of the system as the brakes are applied.

DOT-5 is mentioned because it is unique in its being hydrophobic rather than hygoscopic. Since DOT-5 is silicone based, it is completely different from the other automotive hydraulic fluids.

 

He was using layman's terms for my benefit. He is right, I know this from using glycol in other applications, it will grab water from the air, plastic cannot keep water out. Yep- shock of shocks. Thats why old brake fluid sitting on shelf is supposed to be thrown away.

What else could cause the fluid to turn colors in the reservoir, remember there is no significant pressure nor heat there.

 

I quite honestly do not care, but I see no reason for you to be condescending and sarcastic.

Rather bad form from someone who has greatly contributed to this forum.

 

I should have said plastic does not keep air out, its still better than metal, however it only prolongs the inevitable.
A bottle of unopened coke will go flat, but not as quick as sealed can of coke.

 

Again Cat no one ever mentioned DOT5 still not clue as to why you are trying to making it a point.

The system is completely sealed contrary to your claim. That tiny hole in the top of the cap is there to allow the rubber seal/diaphram (yes SEAL as in that it seals) to lower down so that air does NOT enter into the system rather that rubber seal is allowed to lower down when the fluid is lowered as a result of the brake pads deteriorating. As a supposed certified mechanic I'd expect you to know that. Even you know that air introduced into the system is EXACTLY what we do not want. I'm not saying that water does not get introduced into brake systems causing ill effects but your claim that both brake systems are not sealed and that water is the direct cause of discoloration are blatantly false.

Brake fluid color change by "Yourmechanic"

from Undercar Digest
http://www.babcox.com/editorial/bf/bf50412.htm
"A number of independent sources pointed out that the color of brake fluid cannot be used as an indicator of its condition. One brake fluid manufacturer went on to explain that some new brake fluids have additives that will cause the brake fluid to change color when exposed to brake rubber parts. Another source provided data showing that brake fluid appearing almost pitch black can pass all available tests while other fluid samples appearing to be "good" could fail those same tests. So, one thing that became obvious early on was our industry has to stop recommending brake fluid flushes on the color of the brake fluid. If we don't stop, we will continue to end up on the evening news."

 

NB my offer to do a "real life test" with the brake fluid was a real offer, how you read that as condescending I have no clue. I have the fluid here that won't be use and am happy to add water to prove your point, if that offer makes you feel bad or strikes a nerve it was not at all my intention nor was it in any way sarcastic in nature or intent... if you find that my questioning your claims condescending and that you've offered a lot to the forum therefore no one should question your claim then we strongly disagree.