Help! Brake Fluid

[TheBugster]

I am planning to run my 2007 ZO6 in a track event at Pocono Raceway on Memorial Day. Tech Inspection requires at least DOT 4 brake fluid. The ZO6 comes with and specifies DOT 3 fluid. Is there any problem with flushing and refilling the system with a DOT 4 fluid, such as Castrol LMA? Also, many fluids now available, including Castrol, are synthetic. Is that a problem? Technicians at Criswell Chevrolet have told me that these changes are fine and that many owners make the switch for track events. On the other hand a friend of mine who has a Ford GT told me that it's not recommended for that car because it could damage the brake seals under heavy braking. Anyway I would appreciate any advice that would help clarify this. Also, could it void the warranty?
Thank you. The Bugster

 

[Hib Halverson]

Your Ford GT pal lacks basic car knowlege...of course, that's why he owns a Ford. DOT4 fluid will not "...damage brake the seals under heavy braking."

You can run a DOT4 brake fluid. Look at doing so simply as an upgrade rather than a change to something totally different. Remember "DOT3", "DOT4 and 'DOT5.1" are simply specifications for organic or synthetic, non-silicone based brake fluids. They are not a specific type or brand of fluid.

Generally, DOT4 has higher boiling points than does DOT3 and that's what you want for racing. In fact, if you do track day events regularly and you run on a track that taxes your brakes, you really ought to use a DOT5.1 fluid. They have dry and wet boiling points higher than either DOT3 or DOT4.

DOT4 or DOT5.1 fluid will not void the warranty but if you're racing the car, that in itself may make warranty claims difficult if you attempt to make a warranty claim for a problem which results from on track use.

Lastly, DO NOT use any DOT5 silicone-based brake fluid. It will degrade ABS action to the point of being unsafe.

 

[TheBugster]

Hib, thank you for your very informative response. I should have realized that my Ford GT buddy couldn't have known what he was talking about! I'll go ahead and change the fluid. Also, I agree that participating in an actual race would negate the warranty. This event is a car club track day for Italian cars ( I also have a 1972 Pantera ), Vipers and Corvettes. It's not a competition and lap times are not officially taken, so I don't think that would affect the warranty. Again, many thanks. The Bugster.

 

[Hib Halverson]

You're welcome.
Have fun at the track.

 

[motorman]

Hib, thank you for your very informative response. I should have realized that my Ford GT buddy couldn't have known what he was talking about! I'll go ahead and change the fluid. Also, I agree that participating in an actual race would negate the warranty. This event is a car club track day for Italian cars ( I also have a 1972 Pantera ), Vipers and Corvettes. It's not a competition and lap times are not officially taken, so I don't think that would affect the warranty. Again, many thanks. The Bugster.

i have run laps at poconos in my corvettes and it is damn fast if they let you run without a pace car. have fun but be careful.

 

[TheBugster]

Motorman--Thank you for some really sound advice. You are absolutely right. Pocono is a very high speed course. I used to race there in SCCA events and I've run my Pantera there many times in car club events, but I haven't run my ZO6 there. The ZO6 will be faster and it's been several years since I've been there so I'll have to be careful. You've sure had a lot of Corvettes over the years. I'm really envious..