Question BRAKE FLUID - DOT3 vs DOT4

[YFCvii]

Hello, Visiting a GM Corvette Dealership today and a topic of Brake Fluid came up.
The Dealership Service Tech summed everything up to begin with by saying
" ... all good, everything is moving to DOT4 now ... "
I was all ears in the conversation ... so ...

Yes, if one tracks their Corvette, DOT4 Brake Fluid should be used.
If not tracking, then DOT3 Brake Fluid. Is there anything else to note though ???

Question ...
If a non-tracking Corvette Owner replaces Brake Fluid with DOT4, would the only draw-back from this
be that the next Brake Fluid replacement will be required sooner than if DOT3 is used?

Resulting, if this Dealer advocation is true, might be that a Dealership is switching/moving/using DOT4 so that
this fluid replacement maintenance is required more frequently for the non-tracking vehicle owner.
Ultimately more Service income & shop fees for the Dealership over time.
Just a thought .... but wondering if the vette-tech gurus on here might be able to value-add to this latest discovery.

I will tag @turbozig to see if he has info/opinion ... thx

 

[turbozig]

Hello SN3. Dot 4 fluid absorbs much more water quicker than Dot 3. If you are tracking your car regularly, your brake fluid is being replaced on a much more regular routine, if not even after each track day. Dot 4 does have a much higher boiling point, thus much more suited to the extreme heat and stresses produced by tracking a vehicle. I will stick to Dot 3, it has never failed me yet and I flush it every 2-3 years in all my vehicles. JMHO

 

[G-ForceJunkie]

I'd say I've done a fair bit of brake fluid research over the years, and I've never heard that DOT4 absorbs water quicker than DOT3. From what I've read, there is no performance downside to using DOT4 instead of DOT3. The two are generally interchangeable as well, unless you're on the fringes of their performance envelopes.

 

[WPGZ06]

Never really heard of DOT4 for regular driving/cruising, less heated driving; DOT3 would be the go to otherwise. As for interchangeability, that I will leave to experts on brake fluid, but I'd personally just stick to one unless doing a lot of road and track use.

 

[2KforeverC5]

Hello, Visiting a GM Corvette Dealership today and a topic of Brake Fluid came up.
The Dealership Service Tech summed everything up to begin with by saying
" ... all good, everything is moving to DOT4 now ... "
I was all ears in the conversation ... so ...

Yes, if one tracks their Corvette, DOT4 Brake Fluid should be used.
If not tracking, then DOT3 Brake Fluid. Is there anything else to note though ???

Question ...
If a non-tracking Corvette Owner replaces Brake Fluid with DOT4, would the only draw-back from this
be that the next Brake Fluid replacement will be required sooner than if DOT3 is used?

Resulting, if this Dealer advocation is true, might be that a Dealership is switching/moving/using DOT4 so that
this fluid replacement maintenance is required more frequently for the non-tracking vehicle owner.
Ultimately more Service income & shop fees for the Dealership over time.
Just a thought .... but wondering if the vette-tech gurus on here might be able to value-add to this latest discovery.

I will tag @turbozig to see if he has info/opinion ... thx

I just stickk with the recommendation cuz I do my own flushing. All is good.

 

[1 BAD 9T9]

Hello SN3. Dot 4 fluid absorbs much more water quicker than Dot 3. If you are tracking your car regularly, your brake fluid is being replaced on a much more regular routine, if not even after each track day. Dot 4 does have a much higher boiling point, thus much more suited to the extreme heat and stresses produced by tracking a vehicle. I will stick to Dot 3, it has never failed me yet and I flush it every 2-3 years in all my vehicles. JMHO

Here's my 2 cents on this stuff. You are correct regarding temperature and water absorption. All that I have read is that DOT 3 and DOT 4 are compatible with each other and can be mixed when bleeding brakes etc. I note here that I used DOT 5 in my Crimson Pearl three stage paint on my street rod because it is silicone based and won't eat the paint if spilled. Of course I had Wilwood 4 wheel disc brakes but do not know if DOT5 would be OK in a Corvette. Unlikely, plus I did not track my truck!

 

[YFCvii]

Good responses …appreciated.
Yes preference is as spec’d.
When one services, it’s all about remembering to ask for specifics now as I can see a Dealership putting in something “compatible” and not asking. Used to be like that with motor oil in order to get synthetic. It’s like having to tell them not to rotate tires because I do that myself in seasonal swaps. Now I have to add DOT3 when this pops up. If I dis this all myself, no big deal. Dealership servicing is a real chore now it appears. Thanks for responces so far … it’s rather simple stuff but I think it’s good for posting - future reference - keep em coming

 

[turbozig]

DOT5 is not compatible with DOT3 or DOT4. I have been told by many mechanic experts that to properly convert over to DOT5, you must replace all components with new, or at the very least remove all traces of regular brake fluid beforehand and replace all seals. This is a silicone fluid that does not play nicely with a glycol based fluid. The big benefit to DOT5 is it doesn't damage paint. It is not supposed to be good to use in vehicle's in long term storage, I.E. summer cars. I have never used it so unable to speak from experience, just what I have been told by some older professional mechanics and restoration experts.

 

[1 BAD 9T9]

DOT5 is not compatible with DOT3 or DOT4. I have been told by many mechanic experts that to properly convert over to DOT5, you must replace all components with new, or at the very least remove all traces of regular brake fluid beforehand and replace all seals. This is a silicone fluid that does not play nicely with a glycol based fluid. The big benefit to DOT5 is it doesn't damage paint. It is not supposed to be good to use in vehicle's in long term storage, I.E. summer cars. I have never used it so unable to speak from experience, just what I have been told by some older professional mechanics and restoration experts.

Turbozig I trust I did not mislead you regarding my use of DOT5 on my street rod. EVERYTHING on that truck was new, so there was no mix with DOT3 or DOT4. I said the basic reason I used silicone was to protect against damage on a $8.000 paint job. Hey accidents happen! The crimson pearl tri-colour paint does not show in this picture, but it was on a par with red mist C8 Corvette. Some may argue!

 

[turbozig]

Turbozig I trust I did not mislead you regarding my use of DOT5 on my street rod. EVERYTHING on that truck was new, so there was no mix with DOT3 or DOT4. I said the basic reason I used silicone was to protect against damage on a $8.000 paint job. Hey accidents happen! The crimson pearl tri-colour paint does not show in this picture, but it was on a par with red mist C8 Corvette. Some may argue!

Hey 1 BAD 9T9, absolutely beautiful truck and paint job. spectacular!! I understand fully why you went with DOT5 on it, especially with a fully new brake system. I would love to see it in person someday. In the famous words of Dennis Gage, Happy Motoring!

 

[1 BAD 9T9]

Hey 1 BAD 9T9, absolutely beautiful truck and paint job. spectacular!! I understand fully why you went with DOT5 on it, especially with a fully new brake system. I would love to see it in person someday. In the famous words of Dennis Gage, Happy Motoring!

Thanks for the compliments. Yes it was great show winning truck but it was time to move back to Corvettes. I traded it for a C5 'vert and converted that to a lowered wide body with licence plate 1 BAD9T9 then my wife fell in love with a 2007 Indy Pace car. Corvettes you can drive and enjoy much more than my short wheel base, cramped cab truck. However it did have all the bells and whistles like cruise control and air conditioning. Both pictures on different sections of Route 66. All of you enjoy your rides whatever they are!

 

[DAL]

Hello, Visiting a GM Corvette Dealership today and a topic of Brake Fluid came up.
The Dealership Service Tech summed everything up to begin with by saying
" ... all good, everything is moving to DOT4 now ... "
I was all ears in the conversation ... so ...

Yes, if one tracks their Corvette, DOT4 Brake Fluid should be used.
If not tracking, then DOT3 Brake Fluid. Is there anything else to note though ???

Question ...
If a non-tracking Corvette Owner replaces Brake Fluid with DOT4, would the only draw-back from this
be that the next Brake Fluid replacement will be required sooner than if DOT3 is used?

Resulting, if this Dealer advocation is true, might be that a Dealership is switching/moving/using DOT4 so that
this fluid replacement maintenance is required more frequently for the non-tracking vehicle owner.
Ultimately more Service income & shop fees for the Dealership over time.
Just a thought .... but wondering if the vette-tech gurus on here might be able to value-add to this latest discovery.

I will tag @turbozig to see if he has info/opinion ... thx

The primary differences between the two include the following: DOT 3 brake fluid will absorb less water than DOT 4 from the air over time, meaning you'll need to have your fluid changed less frequently. DOT 4 brake fluid has higher dry and wet boiling points, making it safer for higher temperatures. Cheers!!

 

[Afterimage]

Was gonna start a new thread on this topic but found this one so I'll just add to it. Soon it will be time for me to flush out the BF in the ZR1. Trying to decide what to go with. The 2 previous summer rides (09 Z06, 13 GT500) I had flushed out BF on them and replaced with ATE DOT 4 Super Blue fluid. Worked well for me back then so thinking of going with the same fluid (I believe that the blue fluid is no longer available, they sell the same fluid but is regular BF colour now clear and/or with a slight yellowish hue).

Any other better fluids out there to try?? I've now heard they have a DOT 5.1 fluid which they say is compatible with DOT 3/4 with higher boiling points AND the benefits of silicone DOT 5 fluid. Anyone tried the DOT 5.1??

Not tracking (that I know of right now and in the near future).

If not using DOT 4 or 5.1 what Dot 3 fluid has the highest temp resistance to boiling??