DOT 5 Changeover Practical???

[19thunderbird66]

Was thinking of changing my '66 over to DOT 5 brake fluid while i'm overhaulin' the brake system.I've heard both pros and cons-any input from anyone?? thanx

[simplyconnected]

This topic comes up a lot. Like 'the best engine oil,' everyone has their favorite.

Each car only holds about a cup of brake fluid, so the difference in cost isn't much between types.

Whenever in doubt I always ask the multi-million dollar question:
What do the OEM's use, today?
(How long has DOT-3 been used?)

The OEM's are very exposed to law suits, especially regarding brakes. If a plaintiff can prove there is a better product the OEM's know about it but choose not to use; instant win. Truth is, DOT-3 is still works the best. It also needs to be changed every 24,000 miles or about every two years.

DOT-5 trashes stop light switches, pools water in the lowest areas of your system (usually in wheel cylinders), and gives a 'spongier-feel' to the brake pedal because it is silicone-based. Many classic car seals are not designed for DOT-5 and they break down quickly.

DOT-3 is compatible with everyting, it has a rust inhibitor, and disburses water until it is saturated. (Then it can't absorb, and must be changed.) The biggest scare about DOT-3 is, it eats paint. Yeah, but like antifreeze it is glycol-based and washes off with plain water. If you spill any, hose it off. Your paint will be fine.

Never ever, ever, EVER mix DOT-3 and DOT-5. It turns to a nasty muck and your brakes won't return. If you do change, use LOTS of alcohol to flush each component. - Dave

[19thunderbird66]

Thanx ,some food for thought. bob

[RustyNCa]

FWIW, the only thing I have DOT 5 in are the Outlaw Karts....

And they are designed and built for it, you can't run anything else in them, guess the DOT 3 ruins the system.

I need to get a new photo of Baby Girl's kart, It now matches brothers, except she had to pink and purple where the blue is..

[19thunderbird66]

Ossumm!!! Wow!!!!