Brake Fluid Change???

[kimona]

Took my car to the dealer for an oil change today (53K miles). Service writer told me I needed to change my brake fluid @ $99. I thought I would consult yarisworld before doing this. Is it really necessary now? Thanks.

[tmontague]

Imo I would want new brake fluid in there due to a build-up of moisture causing premature corrosion of the brake components. If it's a dd then there isn't really any performance issues not changing it.

Although I would want to watch that they actually replace all of the old fluid with new and they don't just simply empty and refill the master cylinder reservoir. They should also flush the old fluid out of the lines and bleed the calipers.

[CoryM]

Since brake fluid soaks up water, and is lighter than water, the water collects in the bottom of the system. From my experience as a mechanic it's shown to be more cost effective to do flushes as your calipers/cylinders will last much longer. Especially if the car has expensive calipers (Yaris does not).

Note that this experience is in a low salt area. In salty/rust areas where calipers are damaged due to external factors, on a Yaris it may not be cost effective.

Typically I recommend brake flushes when we do brakes. That way we are consistent and not over-selling to our customers. The generally accepted interval is 2yrs for flushes.

Cheers.

[KimmoKekki]

Brake fluid change is not over selling !

[ex-x-fire]

Pretty easy to do your self.Try to get the old fluid out of the master cylinder, a turkey baster might work. Gravity bleed each brake, one at a time.

[CB900F2]

You should be changing your brake fluid every 2 to 3 years.. I do mine every 2... very easy process... And only cost me about $15.00 in fluid...

[/INDENT]Took my car to the dealer for an oil change today (53K miles). Service writer told me I needed to change my brake fluid @ $99. I thought I would consult yarisworld before doing this. Is it really necessary now? Thanks.

[bronsin]

I just bought a brake fluid tester to settle an argument on a motorcycle forum: Does an opened bottle of brake fluid that is resealed and half full absorb moisture?

Answer: No!

I used the tester on my wife's 12 year old Camry that's never had the fluid changed or bled and the result was >1% moisture which according to the instructions doesn't require changing. Couldn't use it on the Yaris as there no space above the master cylinder. Adding fluid on a Yaris would be a PITA.

The owners manual doesn't call for changing the brake fluid on either the Yaris or Camry. Or even bleeding them. I can't imagine Toyota would put themselves behind a legal 8 ball.

Although when I was able the brake fluid got changed at least every few years.

IMO in the majority of cases it just makes money for the dealer.

[KimmoKekki]

Toyota mainteinance program reguires brake fluid change every 30K km's !
Just called my local Toyota service !
After 12y your tester shows 1% water on fluid .... yep .. looks to be one more MUST have tester [emoji7]
When brake fluid is old soaked and dirty enough it also ruins piston sealsfrom calipers and mastercylinders !
KTM brakes tilt with less than 6y old fluid !

[bronsin]

Toyota mainteinance program reguires brake fluid change every 30K km's !
Just called my local Toyota service !
After 12y your tester shows 1% water on fluid .... yep .. looks to be one more MUST have tester [emoji7]
When brake fluid is old soaked and dirty enough it also ruins piston sealsfrom calipers and mastercylinders !
KTM brakes tilt with less than 6y old fluid !

But the owners manual doesn't call for It. You forgot to say "in their opinion" Toyota service advises it. :biggrin:

Tester shows LES THAN 1%. I also calibrated the tester by mixing 200 ml fresh fluid with 5 ml water. Tester read 2%.

Finally you can change your own brake fluid for $5.

Dealer gets $99.

Clearly they have incentive to talk you into it.

[tmontague]

Fwiw the plastic cowling that covers the brake fluid reservoir can easily be popped out and removed (just the section above the reservoir) this is by design the make it easy to access.

[dogsridewith]

That cowling piece on my 2007 has two tabs that seem to say it would pop off independently of the reported other two pieces of the whole cowl assembly. But that piece seems welded tightly to the piece behind it. Which way does it pry off? Anything else to release but the 2 obvious tabs? Anything else to remove first besides the long rubber molding that removes easily?
Sure would like to get this whole cowl figured out. Thanks.

[bronsin]

Fwiw the plastic cowling that covers the brake fluid reservoir can easily be popped out and removed (just the section above the reservoir) this is by design the make it easy to access.

Have to try it!

[tmontague]

That cowling piece on my 2007 has two tabs that seem to say it would pop off independently of the reported other two pieces of the whole cowl assembly. But that piece seems welded tightly to the piece behind it. Which way does it pry off? Anything else to release but the 2 obvious tabs? Anything else to remove first besides the long rubber molding that removes easily?
Sure would like to get this whole cowl figured out. Thanks.

I just popped those 2 tabs and lifted the small piece of plastic cowling that covers the brake resevoir. You just have to unhook the rubber moulding from the piece

[Motzking1]

Brake fluid absorb moisture over time. That is a fact. Water boils at 212f brake fluid at about 450 degrees Fahrenheit. Meaning if your brake fluid is contaminated with water it will affect the point at which it boils. Wet brake fluid( brake fluid containing moisture above 1%) boils at approximately 311 degrees. Water is much more corrosive than brake fluid meaning it will Rust or corrode the internal components of the braking system at a much faster rate than brake fluid alone. Brake fluid that is open to the atmosphere will fairly quickly absorb moisture. Of course there is a lot of factors that affect this. How long it is open to atmosphere. Ambient temperature dew point ect. Bla, bla, bla. If you live in Seattle like I do it becomes contaminated in the vehicle anywhere from 3 to 6 years. If you live in Arizona probably closer to 6+ years. Those are simply estimates based upon my experience. I work for one of the largest Distributors of brake parts in the Northwestern United states. It is a family business and I am the 3 generation in the business. I am also an ASE Master Automotive technician for 24 years. I do know a thing or two about brakes. With that being said I recommend replacing the fluid whenever the brakes are done. It's just a logical time to do it it's approximately the correct interval. Of course that varies with mileage driven and all that good stuff. Why I pay to have a brake flush done independent of a brake service. It just doesn't make Financial sense. It should be done at the time the brakes are serviced in a proper brake service. Brakes work as an entire system together. Outside of a normal service and replacement of brake pads shoes it's just an unneeded expense. I hear what everyone is saying about the corrosion inside of the system and possibly affecting calipers and are wheel cylinders. I have personally done thousands of brake services on thousands of vehicles. Of 1000 Vehicles serviced about 3 have ever had a caliper Frozen from corrosion internally. I know calipers are replaced quite often and that's okay with me since it makes my family money. Go right ahead and replace those calipers but I rarely ever see them go bad from internal corrosion. 99% of the time it's from a slider that is external that is frozen or damaged not internal damage. If you're worried about the expense of replacing calipers due to internal corrosion you're worried about something that is highly unlikely ever to affect your vehicle. The brake fluid flush independent of a brake service is just a waste of money in my opinion. Wait and tell your servicing your brakes and do it then it should be less labor since you're already in there. That's just my two cents.

Sent from my SAMSUNG-SM-N900A using Tapatalk

[CoryM]

Brake fluid absorb moisture over time. That is a fact. Water boils at 212f brake fluid at about 450 degrees Fahrenheit. Meaning if your brake fluid is contaminated with water it will affect the point at which it boils. Wet brake fluid( brake fluid containing moisture above 1%) boils at approximately 311 degrees. Water is much more corrosive than brake fluid meaning it will Rust or corrode the internal components of the braking system at a much faster rate than brake fluid alone. Brake fluid that is open to the atmosphere will fairly quickly absorb moisture. Of course there is a lot of factors that affect this. How long it is open to atmosphere. Ambient temperature dew point ect. Bla, bla, bla. If you live in Seattle like I do it becomes contaminated in the vehicle anywhere from 3 to 6 years. If you live in Arizona probably closer to 6+ years. Those are simply estimates based upon my experience. I work for one of the largest Distributors of brake parts in the Northwestern United states. It is a family business and I am the 3 generation in the business. I am also an ASE Master Automotive technician for 24 years. I do know a thing or two about brakes. With that being said I recommend replacing the fluid whenever the brakes are done. It's just a logical time to do it it's approximately the correct interval. Of course that varies with mileage driven and all that good stuff. Why I pay to have a brake flush done independent of a brake service. It just doesn't make Financial sense. It should be done at the time the brakes are serviced in a proper brake service. Brakes work as an entire system together. Outside of a normal service and replacement of brake pads shoes it's just an unneeded expense. I hear what everyone is saying about the corrosion inside of the system and possibly affecting calipers and are wheel cylinders. I have personally done thousands of brake services on thousands of vehicles. Of 1000 Vehicles serviced about 3 have ever had a caliper Frozen from corrosion internally. I know calipers are replaced quite often and that's okay with me since it makes my family money. Go right ahead and replace those calipers but I rarely ever see them go bad from internal corrosion. 99% of the time it's from a slider that is external that is frozen or damaged not internal damage. If you're worried about the expense of replacing calipers due to internal corrosion you're worried about something that is highly unlikely ever to affect your vehicle. The brake fluid flush independent of a brake service is just a waste of money in my opinion. Wait and tell your servicing your brakes and do it then it should be less labor since you're already in there. That's just my two cents.

Sent from my SAMSUNG-SM-N900A using Tapatalk

Yeah, my shop rarely replaces calipers since we check pins and pistons prior to quoting. Pins or swollen pads are definitely the common problems, and lots of other shops call for caliper replacement just because the pins need some lube. I do still find some stiff caliper pistons, but very low percentage (and usually those stupid e-brake in caliper design or fixed calipers where one piston is stiffer than the others.).

I always figured flushing when relined was best since you are disturbing the sediment in the calipers when pushing the pistons back. No better chance to get it out than when it is loose. It's also just easier as a shop to keep track of when you have flushed customer cars. I've yet to boil brake fluid with street pads. I've found even with unflushed fluid the street pads will fade/melt before the fluid boils but it's probably pretty close. Performance pads are a different story though.

Had a newer AMG G-wagon in a few weeks ago and it needed 4 calipers due to stiff pistons. I think they were $3200 and had to come from Germany. :laugh:

[dogsridewith]

Last two posts sound great. There are several ways to move brake fluid through the system. I do it w/o assistant using a MityVac (suction device, w/ gauge, also used for testing various vacuum diaphragms). Ever encounter or hear trusted account of the Mity Vac pulling in air around wheel cylinder or master cylinder seals...thereby, of course, ruining the bleed job.

[Motzking1]

I imagine it is possible. I have used a Vacuula brand bleeder and if turned up they can produce almost as much vacuum as a vacuum pump. 28+ in. Of mercury. I have not had a problem before but do not normally use it. I still use the old fashion two person down and hold method. I am careful not to travel the pedal much outside it's normal travel ammount. It seems by bleeding the pedal and therefore the master cylinder too far down Beyond its normal range of travel tends to increase the instance of master cylinder failure. My guess is because you're traveling outside of where the normal wear Groove kind of happens inside the cylinder therefore increasing the chance of damaging the Rubber seal. All so funny what you say about the Mercedes as we have sold a massive amount of calipers on some of the late model Mercedes. You know there's a problem when you go to the shop to pick up Part you would normally stock 2 or 3 sets of and there are 60 sets. It's a real High moving part. I honestly have not dove in to what the failures are with the late model MB calipers. In the past the big failures in big numbers where when some manufactures went to phenolic Pistons instead of metal ones. They cracked they chipped they got soaked with fluid and expanded. Most of those issues have worked themselves out. Most manufactures abandoned the phenolic piston design. But there have been others that have tried to make Ceramics and other Exotics pistons for calipers. Each one has their own little quirk

Sent from my SAMSUNG-SM-N900A using Tapatalk

[Motzking1]

Toyota tends to use time tested parts and methods instead of going for the newest latest and greatest. That makes them reliable and easier to service

Sent from my SAMSUNG-SM-N900A using Tapatalk

[CoryM]

Last two posts sound great. There are several ways to move brake fluid through the system. I do it w/o assistant using a MityVac (suction device, w/ gauge, also used for testing various vacuum diaphragms). Ever encounter or hear trusted account of the Mity Vac pulling in air around wheel cylinder or master cylinder seals...thereby, of course, ruining the bleed job.

I've never seen air pulled into the system except for when master cylinders fail (or when someone lets the fluid level get too low). The suction will cause air to pull past the nipple threads and into the system but it immediately goes out the nipple. This is why you will see bubbles in the mityvac even though its well sealed to the nipple. The amount of air that remains is not enough to cause issues for street cars or even be noticeable when testing. On a high end racecar you may want to give it a few manual bleeds, but I've not found that required on the ones I've played with. Professional brake flush machines are just vacuum suckers on each bleeder, and several PSI of fluid on the master cylinder. It's probably a bit better than just vacuum, but mostly it's probably just faster. We also put 2L of fluid through the system which is probably excessive for most cars, but some sure need it.

One day I should do a write-up or video about brake servicing. Very few people do it properly.

[Motzking1]

Interesting I would really like to see a good write-up or video on brake bleeding I think that's a great idea. You're right being as that it really hasn't changed a lot and over a hundred years there are a lot of people who still must understand it and the whole notion is sometimes a little mysterious as to when and how. It seems the same is true of disc brake servicing. I have seen a lot of brake jobs done and I've seen as many different ways of doing it as I have seen technicians to do it. Some technicians Grease the pad Hardware. Some people put silicone lubricant grease oil whatever on the back of the pad and swear by it. A lot of people misunderstand what a pad shim is what it does. Getting straight answers to these questions has been sometimes difficult. Even out of the manufactures themselves. I of course have some strong opinions on it being in the automotive service business an automotive parts business my whole life. But as strong as my opinion on what to do I still get a lot of people who disagree. Take the pad hardware for example I get people who swear by lubricating the pad Hardware. I strongly believe that grease and oil attract dust and debris. I don't lubricate them. Not to mention all the ones I sell these days come with a pre lubricated Teflon coating to them. But there are many varied opinions on how to do this and what works.

Sent from my SAMSUNG-SM-N900A using Tapatalk

[tmontague]

Last two posts sound great. There are several ways to move brake fluid through the system. I do it w/o assistant using a MityVac (suction device, w/ gauge, also used for testing various vacuum diaphragms). Ever encounter or hear trusted account of the Mity Vac pulling in air around wheel cylinder or master cylinder seals...thereby, of course, ruining the bleed job.


I have tried the mighty vac and no matter what it pulls air in through the bleeder for me. That is even with covering it with grease as well as using thread sealant tape.

I just use the 2 person method which is cheap. Quick and woke well.

Down the road I'll likely buy a pressure bleeder but for now the 2 person works fine

[Motzking1]

I'm not buying the fact that the mighty vac is pulling air with grease and thread tape. That does not make coming sence. Think about that. You think because you see air in the line it came from ambient air? Not likely. What is more likely is the mighty vac is in a vacuum. All matter and it's state are affected by atmospheric pressure or lack thereof. In other words you don't find a lot of water 4 brake fluid for that matter in its liquid form in a vacuum. The reason being without the atmospheric pressure of the Earth's atmosphere water becomes a gas. When you use the Mighty vac it pulls a vacuum a strong vacuum with the bleeder being the orfice tube in the system. Anything behind that or forced tube is in a strong vacuum. What you're seeing is air. But likely where it came from his lack of atmosphere causing vapor to boil. This is called Boyle's Law

Sent from my SAMSUNG-SM-N900A using Tapatalk

[bronsin]

I have tried the mighty vac and no matter what it pulls air in through the bleeder for me. That is even with covering it with grease as well as using thread sealant tape.

I just use the 2 person method which is cheap. Quick and woke well.

Down the road I'll likely buy a pressure bleeder but for now the 2 person works fine

I agree mityvac is overkill. Spend your money on something useful!

[dogsridewith]

Mityvac instructions say you will see big spurty bubbles when air is coming out of the system, then steady little bubbles (which are no problem) of air being pulled through the loosend nipple's threading (from ambient air) and mixing with fluid being pulled through the system...into the cup...until the nipple is closed...all the while with the operator paying attention to the gauge and squeezing the vacuum pump handle enough to maintain some vacuum.
There's no vacuum diaphragms to Mityvac check on Yaris? People would have saved millions of dollars tuning the late 1980's Tercel fleet finding broken diaphrams in distributor advances and emissions gizmos instead of buying new or rebuilt carburetors.
---
I can see using some grease on bleeder nipples to prevent rusting, but grease or Teflon tape can't be expected to seal straight threads. The seal is at the end of the nipple.

[CoryM]

Air will pull past the coarse bleeder threads when using vacuum on the bleeder. Especially on rebuilt calipers with poorly machined threads. The threads are not designed to seal at all, and are loose enough that even fluid can pass through them readily when the bleeder is loose (which is annoying because it means when I do flushes, brake fluid drips on the hoist). Just make sure to close the bleeder while there is a vacuum still on it and you shouldn't have any air problems. If you loose vacuum while the bleeder is open, it will pull air back into the brake system. The mityvac may be harder to use than a flusher because of this. The best way to use the mityvac for the final bleed is probably to pump the hell out of it with the bleeder closed, crack the bleeder and then close it again before vacuum runs out. Otherwise you may keep getting air sucked back into the system.

Do not use any petroleum based greased where it can contact your brake fluid or rubber. It will swell the seals and destroy them.

[tmontague]

The problem I had was that not enough fluid was being drawn down to the bleed nipple to do an adequate flush and bleed. The vacuum was being maintained without issue but I find putting pressure at the main reservoir always flushed way more fluid through the system. I would have a small drop with the mighty vac and a full rush of fluid with the 2 person method.

As long as you have a helper and a block of wood to stop the pedal from going all of the way down it take very little time and gets everything through the brake lines and out.

[KimmoKekki]

Why you should not hit brake pedal to the floor ??

[CoryM]

Why you should not hit brake pedal to the floor ??

Because the master cylinder piston only moves around 1/2 stroke in normal use. The bore wears, which leave a ridge at the end of it's normal stroke. So when you bleed and go all the way to the floor, the rubber piston seal has to go over that ridge and it tears. Then you have to replace the master cylinder.

Never go more than 1/2way to the floor when bleeding (unless master cylinder has just been replaced).

[KimmoKekki]

So like said ... pedal to the metal !!

[dogsridewith]

The problem I had was that not enough fluid was being drawn down to the bleed nipple to do an adequate flush and bleed. The vacuum was being maintained without issue but I find putting pressure at the main reservoir always flushed way more fluid through the system. I would have a small drop with the mighty vac and a full rush of fluid with the 2 person method...
Then your problem was unclogging the system BEFORE being able to bleed it.
I've only seen this level of clog--rusty dirt-- happen inside the tip of the nipple, or maybe just inside the wheel cylinder...resolved by removing the nipple completely and clearing nipple/cylinder with a drill bit(s). Stomping the pedal would certainly produce more system pressure to clear rust in the lines, sticky proportioning valves, etc.

[bronsin]

Air will pull past the coarse bleeder threads when using vacuum on the bleeder. Especially on rebuilt calipers with poorly machined threads. The threads are not designed to seal at all, and are loose enough that even fluid can pass through them readily when the bleeder is loose (which is annoying because it means when I do flushes, brake fluid drips on the hoist). Just make sure to close the bleeder while there is a vacuum still on it and you shouldn't have any air problems. If you loose vacuum while the bleeder is open, it will pull air back into the brake system. The mityvac may be harder to use than a flusher because of this. The best way to use the mityvac for the final bleed is probably to pump the hell out of it with the bleeder closed, crack the bleeder and then close it again before vacuum runs out. Otherwise you may keep getting air sucked back into the system.

Do not use any petroleum based greased where it can contact your brake fluid or rubber. It will swell the seals and destroy them.


Sounds like an excellent reason not to use a mityvac.

[dogsridewith]

Which reason are you addressing? Air pushing past bleeder threads is irrelevant. I never come close to loosing vacuum with the bleeder open. The gauge is right there to watch and I'm just cracking the bleeder w/ an 8 mm wrench while watching the fluid/bubble mix run through clear tubing...very easy to stop in an instant w/ a tiny movement of the wrench. MityVac has enough vacuum reservoir to do this easily. It helps if everything is attached (the tubing to the bleeder nipple, and all other tubing pieces) and hung/placed (the pulled-fluid receiving cup) sufficiently.

[bronsin]

Which reason are you addressing? Air pushing past bleeder threads is irrelevant. I never come close to loosing vacuum with the bleeder open. The gauge is right there to watch and I'm just cracking the bleeder w/ an 8 mm wrench while watching the fluid/bubble mix run through clear tubing...very easy to stop in an instant w/ a tiny movement of the wrench. MityVac has enough vacuum reservoir to do this easily. Lots of auto mechanic work takes two or three hands. This, just one, if everything is attached (the tubing to the bleeder nipple, and all other tubing pieces) and hung/placed (the pulled-fluid receiving cup) sufficiently.

CoryM says one thing and you say the opposite. You guys settle it.:smile:

As for me I can bleed my brakes all by myself without a mityvac and usually without help. Ive bled the brake system of the ST1300 motorcycle alone, a VERY Rube Goldberg system with TWO master cylinders one lever actuated one front brake rotor actuated! Very complicated and very nuts!:iono:

How nuts? The front wheel has two discs each with its own caliper. When its pads grab the disc, the left caliper pivots actuating a secondary master cylinder, which applied the rear brake. Actually, it applies one piston of the three pistons on the rear caliper. Totally CRAZY! VERY complicated!

I can always get someone to help if needed.