Changed my brake fluid today

I've decided to change my brake fluid every two years. This was my fluid after two years and 26,000 miles. Not bad but clearly a difference. This is my second time changing it, first time it looked worse at 3 years and 33,000 miles so I will be sticking to every two years. This is Prestone DOT3.

Old fluid on Left new on Right

 

It is clean still, but definitely time to replace! Nice work! That's the next thunk I plan on when returning from a road trip...look at your PS fluid, too...good time to swap it!

 

I need to do this on my truck and the wife's van. Can you list what tools you used to do it?

 

Interesting. I think my 2020 may need a bleed. Brake fluid does absorb moisture, which may rot the inside of my calipers.

I have been using ATE Original TYP 200 Racing Quality DOT 4 Brake Fluid in all my cars. Any reason I can’t use it in my Tundra?

 

You can use either in the 2020, but I believe DOT 3 absorbs moisture at a slower rate than DOT 4, so it needs serviced less often. DOT 4 resists heat better so it is better if you do a lot of heavy braking from towing, racing, pursuit driving, etc. OR maybe if you live in an extremely hot climate. So, in my opinion, if you use DOT 4 you should probably flush it out ever 1-2 years or so depending on your climate, regardless of how you use it. But I would regularly test it to be sure. So, really unless you "need" DOT 4, it makes more sense to stick to DOT 3 if your vehicle specs it (unless you just have a thing for bleeding brake systems more often).

I don't go by mileage or years on my brake fluid. I do a double test with an electronic tester and a paper test strip every other OCI to tell me when. I'm getting ready to do mine for the first time and it is at 60,000 miles.

 

I've done a complete swap of PS fluid, now I just empty and fill the reservoir every now and again.

I use a Mityvac to bleed the lines till I get clean fluid out. The bleeders up front are 10mm and in back are 8mm. Then I use the Techstream bleeder, only because it operates the ABS module to help get any possible air out.

I'd stick to using DOT3 since thats all it calls for, DOT3 and 4 are not interchangeable fluids. As mentioned as well, DOT4 absorbs moisture faster as well.

 

Actually, I think DOT 3 and 4 are compatible. They are not compatible with 5 or 5.1 however. And DOT 4 is backwards compatible with 3, but not vise versa. I have seen several bottles of brake fluid that actually say DOT 3 and 4 on the label (Motul, Amsoil, Valvoline, etc).

Just curious, do you ever test your brake fluid or did you happen to test this last batch? I'd be curious what it says the water content is

 

I swapped from DOT3 to DOT4 in May of this year. I was on the fence of swapping to DOT5.1. Decided to go with DOT4 with some of the hard braking I sometimes encounter. It's hard to tell the difference since I installed braided stainless lines at the same time. Braking does feel more secure and I feel less brake fade.
Thanks for the reminder to check for moisture in the DOT4 and to change earlier than DOT3.

 

For anyone wanting to remove the plastic screen in the master cylinder, I found a paint can opener tool with the offset at the end works very well.

 

Nice!

 

Ah gutcha, I just always have stuck with what ever it says depending on vehicles, my bikes use 4 and the truck uses 3. I've never actually tested any fluid I've changed. Typically the greenish color means it has absorbed water though. Usually the fluid down closest to the calipers is the dirtiest, many people see clean fluid in the reservoir but dont realize any type of sediment will settle at the lowest point which is where is can cause issues like seized calipers.

 

Very interesting discussion.

From the Website: ATE TYP 200 Brake Fluid exceeds all DOT 4 standards and is designed to excel under the extreme demands of race cars and high-performance driving. The high wet and dry boiling points make this fluid an excellent choice for street driven vehicles as well. ATE TYP 200 is compatible with all DOT 3, DOT 4, and DOT 5.1 brake fluids. The formula offers a minimal drop in boiling point due to outstanding water binding properties resulting in a long-lasting fluid that can provide optimal performance for up to three years under normal highway driving conditions.

I just happen to have some ATE 200 as I flush my other cars. I had Ridgeline I didn’t change the fluid. It absorbed water and the calipers went to hell. Lesson learned.

I tow with the Tundra. But have never had any issues with the original brake fluid.

 

BTW: The reason I used ATE in the first place was because they had two fluid colors, clear and Blue. It made it very easy to tell when you had completely flushed the system. They discontinued the blue.

 

Thanks again for this discussion. I was going to go with DOT5.1 but decided to try DOT4. Just re-read and as stated DOT 3-4-5.1 are compatible. May try DOT5.1 at next change.

 

As I've researched this a little bit more now after posting this just be aware DOT4 and 5.1 will both absorb water faster than DOT3 basically the higher the number the faster it absorbs water and sooner it needs to be changed. For this reason DOT3 every 2 years works just fine for me. I've never had any issues with 3 and wouldn't want to have to change it out any sooner since it is kind of a timely process especially by yourself.

 

Just like checking out new products.
That's why I said Thanks for this discussion as its a great reminder to change the fluids earlier. It's crazy to think how many people have 10+ years on their fluid. I mention it to people about changing the brake fluid and you get the "really?" response.

 

I used to be in that group because i thought it was hard to do. In the end old fluid will work until it ruins other parts in your brake system in which then people will replace it with those parts lol.

 

A fluid evacuator with brake line attachment makes this a one man job.

https://amzn.to/3YEnLT8

 

Thanks for the link!

 

How big of a PITA is it to empty that thing?

 

It's not. Just crack open the cap and dump it down a funnel to your favorite used automotive fluid jug.

 

This one looks to be there brake specific kit.

$59 FOUR UNCLES 3L Brake Bleeder Vacuum Pump Kit - Pneumatic Brake Fluid Extractor with 1L Refilling Bottle & Adapters for Automotive Bleeding, One-Person Operation

https://www.amazon.com/FOUR-UNCLES-Extractor-Refilling-Adapters/dp/B0C65G2KQ3/?_encoding=UTF8&th=1

 

How much brake fluid do you need for the flush?

 

I would think a quart (32 ounces) would be enough. It is cheaper by the quart anyway. Not that it's real expensive. I can get Mag1 or SuperTech DOT 3 32 oz for about $6.

On a side note. I'm not real sure if this is an actual indicator or not, but I bought a bottle last week that was all sort of "sucked in" like it was under vacuum. When I opened it and tested it, it tested bad with over 4% water. I returned it for a bottle that looked and felt normal; like it had pressure when it was squeezed telling me the seal was good. That bottle tested 0%. I am going to assume from this point forward that a caved in bottle means there is a bad seal and there is water in that fluid.

Before I put any fluid in, I always test it. Testers are very cheap; electronic and/or paper. You can also test it with a multimeter if you have one already. There are youtube videos on how to do that. None of these are as good as a boiling point tester, but those are pretty expensive. That's why I try to use two cheap methods to confirm.

I never save or use opened brake fluid if I'm flushing unless I just opened it. So, buy the big bottles to flush, save what's left to top off after you drive for a few days in case there was any air in there that has worked out, then discard/recycle the rest. Then I just top off with new small bottles as the pads wear down if needed. Just my two cents.

 

I went with the Bosch fluid and so far it’s good. I ended up using a quart and a half for a good flush(also changed to the sdhq brake lines at the same time). One thing to remember is that at least on my ‘18 you can’t get a suction tube to the rear of the master. I got as much as possible and when refilling I noticed it made the old fluid float to the top. Vacuumed down an inch or so again to get it and it seemed to work.

 

FROM ATE TECH SUPPORT:

"Thank you for contacting Continental Technical Support.

Dot 4 absorbs moisture at a slower rate than Dot 3, however, the boiling point of Dot 4 will drop a greater amount with the same % moisture than it will with Dot 3. It’s a bit confusing."

 

Interesting. This was a study done in 2019 by the Army and several doctors of chemistry (listed on the first page under authors). It is a lot to read, but it looks to me like this study more or less refutes the tech support person from ATE. I'm just an average guy reading this stuff, but it appears to me on page 30 and 31 that DOT 3 absorbs water the slowest over time and is the least hygroscopic overall. It's really getting into the weeds, but I thought it was interesting. I found this a year ago or so over on BITOG.

https://apps.dtic.mil/sti/pdfs/AD1091780.pdf

 

Thanks!

Best bet is to do what JOE 333x, change it on a schedule.

 

Brake fluid exchange is something I've never done (and probably should). What's the preferred method for DIYing this?