I Decided on DOT3, Am I Wrong?

[ad244]

Hey BITOGers,
I recently did a full brake change consisting of all 4 pads and rotors on a 2010 Honda Civic. When it came time for brake fluid I made a call to use DOT3 instead of the perhaps more advantageous DOT4 when bleeding the entire system. My decision was based off a few factors:

1. I didnt know what had been used previously and I figured the older spec would be better on an older car.
2. If DOT4 absorbs more water, maybe DOT 3 will last longer?
3. I assume pedal feel wouldnt be any different?

Did I mess up?

 

[kschachn]

Doesn’t your manual say you can use either one?

 

[GSCJR]

DOT3 is the OE spec.

 

[slacktide_bitog]

There is no problem using the DOT3 like your Civic originally came with

The most important thing is to change it regularly. That is much more important than what brand you use or using DOT3 vs DOT4. Honda says to change it every 3 years, but you can probably get away with just doing it when you replace the pads and rotors.

 

[Jake_J]

The difference between DOT3 and DOT4 is tiny, most manufacturers treat them as interchangeable when they specify brake fluid as DOT3 or DOT4. You would never notice any difference between the two on a car that driven on the streets. So no, you certainly didn't mess up.

 

[Hall]

Did I mess up?

Using what the owner's manual says can't be a mess up

 

[JimPghPA]

On the Honda CR-V owners forum one post was from someone who has had many Hondas for many years with many of them getting way over 100,000 miles on them, that person said they changed the brake fluid using DOT 3 low cost fluid from places like Walmart every 2 years and never had any problems.

It does look like water absorbed into the fluid from air is the big thing that destroys brake systems with rust if allowed to get to be too high a concentration. So changing it often is probably the most important thing. One of the YouTube videos mentioned high levels copper in the brake fluid if not changed often enough can be a problem. So there may be more than just water in the fluid to be concerned about.

There are some YouTube videos on how to do a reverse flush. Some good YouTube videos show using a Phoenix reverse brake flush system, and to start from the back farthest away form the master and then other back, and then fronts again furthest away first. Though now days with the 4 output anti-lock systems under the hood of many vehicles, maybe when doing a reverse flush it should be started furthest from that jungle of plumbing.

 

[doitmyself]

No reason to second guess this whatsoever. As stated, it is the recommended OE fluid. The differences boil down to Dot 3 handling moisture a bit better (depending who you believe) and Dot 4 handling extreme heat a bit better, in my opinion. Dot 4 might perform better if you live in the mountains, haul trailers, or otherwise drive (brake) your car aggressively. Otherwise, I am not convinced it is better, just different.

The moisture absorption and reaction mechanism of DOT 4 is debated on the interwebs. I agree with periodic fluid changes.

 

[meep]

I prefer dot 3, due to a significantly tiny difference in pedal feel, unless it calls for dot 4, in which case it happily goes in. No issues with dot 3 if the manual calls for it.

 

[MasterSolenoid]

I have used both.
I feel best knowing I flushed the whole system every two years.

 

[wildcatgoal]

Pff... the only DOT3 I've ever bought is Supertech. DOT3 is DOT3, bros. If the car came with it and you aren't racing it... generic DOT3 for me.

 

[demarpaint]

The last two brake fluid flushes I did I used "Synthetic" Valvoline DOT 3&4 brake fluid. On sale it is priced in line with DOT 3 brake fluid, occasionally less. I change it every two years and have no problems to report.

 

[JMJNet]

It looks like you have answered your own questions with your own justification???

 

[edyvw]

Hey BITOGers,
I recently did a full brake change consisting of all 4 pads and rotors on a 2010 Honda Civic. When it came time for brake fluid I made a call to use DOT3 instead of the perhaps more advantageous DOT4 when bleeding the entire system. My decision was based off a few factors:

1. I didnt know what had been used previously and I figured the older spec would be better on an older car.
2. If DOT4 absorbs more water, maybe DOT 3 will last longer?
3. I assume pedal feel wouldnt be any different?

Did I mess up?

How long it lasts depends on numerous factors not jus whether fluid is DOT3 or 4. It depends how porous your brake lines are (all are, regardless that they hold pressure), what is moisture content in the air etc.
So change every 2 years, and you will be fine.
DOT4 is go to for Euro cars, and while people think DOT4 is just DOT4 there are numerous differences between each. Minimum DOT4 boiling point is 230c, but you have DOT4 fluids with boiling point 335c or 345c. Than there is DOT4 LV for ESP systems.

 

[nthach]

While DOT4(preferably Castrol, ATE, Pentosin or Bosch) is my MO, some DOT3s are more “lubricating” than others. This is more true for Japanese OEM fluids(and the dealer-packaged) ones. There have been recalls/TSBs issued by Honda and Toyota for master cylinder squeal or leaks caused by using aftermarket DOT fluids missing one ingredient the OEM fill has.

 

[nicholas]

I think all brake fluids must be synthetic.
Not like Dino engine oils.

 

[Hall]

There have been recalls/TSBs issued by Honda and Toyota for master cylinder squeal or leaks caused by using aftermarket DOT fluids

Is that still the case with modern Honda and Toyotas ? I think that maybe pre-2000 or pre-2005 or it could have been the case. In fact, we got a recall notice for our '05 Odyssey for the master cylinder, related to o-rings or seals that leaked. Honda blamed it on "incompatible" brake fluid too. I wonder if the replacement sealing parts were in fact more tolerable to non-OEM brake fluid ? I guess it is the case.... Heh, in 2012, Honda still says to use Honda fluid... Using non-Honda fluid "can cause corrosion and decrease the longevity of the system".

 

[Hall]

The last two brake fluid flushes I did I used "Synthetic" Valvoline DOT 3&4 brake fluid.

That's what I bought and used until we got our Fusion which specs DOT 4 LV. My son and I put this same fluid in his '12 Accord but at the same time as we did a full brake job (pads + rotors on both axles) so it was nearly impossible to "feel" a difference from the fluid. LV brake fluid is supposed to much better for ABS. I'll put it in my G35 and the Civic when the time comes too.

 

[demarpaint]

That's what I bought and used until we got our Fusion which specs DOT 4 LV. My son and I put this same fluid in his '12 Accord but at the same time as we did a full brake job (pads + rotors on both axles) so it was nearly impossible to "feel" a difference from the fluid. LV brake fluid is supposed to much better for ABS. I'll put it in my G35 and the Civic when the time comes too.

In my case all of my vehicles call for DOT 3, so the Valvoline product was the perfect price/match imo.

 

[The Critic]

Is that still the case with modern Honda and Toyotas ? I think that maybe pre-2000 or pre-2005 or it could have been the case. In fact, we got a recall notice for our '05 Odyssey for the master cylinder, related to o-rings or seals that leaked. Honda blamed it on "incompatible" brake fluid too. I wonder if the replacement sealing parts were in fact more tolerable to non-OEM brake fluid ? I guess it is the case.... Heh, in 2012, Honda still says to use Honda fluid... Using non-Honda fluid "can cause corrosion and decrease the longevity of the system".

It’s still an issue today, but maybe not with Honda/Toyota. GM has issues with noise if the fluid contains inadequate lubricants:

https://static.nhtsa.gov/odi/tsbs/2014/MC-10112028-9999.pdf