[English Rebel]

Who here has their brake fluid changed and at what intervals. When I had a Ferrari 360 it was an annual requirement. However I'm not sure if our cars use the same old DOT3 or 4, or if they changed to DOT5 which is silicone and doesn't to my knowledge absorb water like the glycol-ether ones. I once did a body off restoration of a 64 TR4 and as all the brake components were brand new, I used silicone fluid.
If glycol-ether, I'm thinking every 24 months and mine's coming up on that.
Alan

 

[jsvette]

Scheduled brake fluid change is at 150,000 miles or every 10 years per the Owners Manual.

 

[English Rebel]

It says DOT 3 which is the same stuff manufacturers have been using for years. I would think that after 3 years, let alone 10 years, it would have absorbed enough moisture to cause corrosion.
Alan

 

[ALCHMST]

 

[jsvette]

ALCHMST, they apparently changed the recommendation for C7s beginning with 2015 as here is the page from the 2014 manual:

 

[rdslon01]

Yelp, my 2016 owner's manual says the same thing: replace the brake fluid every 3 years or 45,000 miles, whichever comes first.

 

[ALCHMST]

Didn't think you had it wrong jsvette. Posted my pages to show I was not crazy. Thanks for posting you rpages so we can at least say we have complete information and comparison for future reference as subjects often cycle on forums like this. Don't know about you guys but makes me a bit nervous when GM can change their mind on something as routine and long tested as brake fluid.

 

[Milliwatt Rob]

Every three years or so seems the norm for many makes and models or cars. In the meantime, if you are concerned, there are brake fluid moisture content testing strategies and devices. One uses a litmus paper type approach, the other uses an electronic tester that is cylindrical and looks like a pocket flashlight, except instead of a lamp on the end, it has a pair of contacts that you immerse in the fluid reservoir. It measures the conductivity of the fluid, which in turn is a measure of how much moisture it has absorbed.

 

[jsvette]

Didn't think you had it wrong jsvette. Posted my pages to show I was not crazy. Thanks for posting you rpages so we can at least say we have complete information and comparison for future reference as subjects often cycle on forums like this. Don't know about you guys but makes me a bit nervous when GM can change their mind on something as routine and long tested as brake fluid.

No issues While it is a bit curious as to the significant change in recommendations, I personally would not go more than 3 to 5 years max before changing brake fluid (even here in the uber dry Mojave Desert).

 

[billkahle]

I concur about changing brake fluid between 3 to 5 years or just before a track day. I changed the factory DOT 3 fluid in my '16, C7 to ATE Blue TYP 200, DOT 4 before taking it to Mid-Ohio. I plan to keep DOT 4 and not switch back to DOT 3.
I think the 2019 C7s come with DOT 4 brake fluid from the factory. And DOT 4 clutch fluid in all C7s. I have been changing brake fluid in my cars for a long time. In performance cars I would switch between ATE DOT 4 blue and ATE DOT 4 amber brake fluid. Switching colors made changing fluid very easy. You knew when the new fluid was in. Sadly our government outlawed colored brake fluid a few years ago allowing only amber brake fluid to be sold. I have used DOT 3, DOT 4 and DOT 5.1 but never DOT 5. DOT 5 should only be used in show cars that spend a lot of time stored and driven to shows, in my opinion.

 

[billkahle]

Our Government outlawed colored brake fluid a few years ago allowing only amber colored fluid to be sold.
Because I can not acquire the ATE blue brake fluid domestically I opted to make my own. I don't track my cars anymore so my home brew blue brake fluid will be used in my daily drivers. I add .5 ml of RIT "dry" Navy Blue dye to 12 ounces of any brand of DOT 3 brake fluid. Using a glass jar I mix the Rit dye with 4-6 ounces of brake fluid. Using paper coffee filters I strain the blue fluid back into the brake fluid bottle. For some reason the RIT dye contains some sort of solids that needs to be filtered out.
I don't know why the dye couldn't be used in high temperature DOT 4 or DOT 5.1 brake fluids for track day use.
I really like the ability to alternate between blue and amber brake fluid when changing brake fluid.

 

[Stoan]

Our Government outlawed colored brake fluid a few years ago allowing only amber colored fluid to be sold.
Because I can not acquire the ATE blue brake fluid domestically I opted to make my own. I don't track my cars anymore so my home brew blue brake fluid will be used in my daily drivers. I add .5 ml of RIT "dry" Navy Blue dye to 12 ounces of any brand of DOT 3 brake fluid. Using a glass jar I mix the Rit dye with 4-6 ounces of brake fluid. Using paper coffee filters I strain the blue fluid back into the brake fluid bottle. For some reason the RIT dye contains some sort of solids that needs to be filtered out.
I don't know why the dye couldn't be used in high temperature DOT 4 or DOT 5.1 brake fluids for track day use.
I really like the ability to alternate between blue and amber brake fluid when changing brake fluid.

Adding water based dye's like RIT to your brake fluid is not a good idea. Brake fluid is designed to absorb water and keep it away from components. Adding a powder to this will impact the fluids ability to absorb moisture and lower the boiling. It could also allow the powder to absorb moisture and create corrosion. If you want blue brake fluid order the real thing from Europe.