Dot 4 or Dot 5

[Jack J.]

[Mark A.]

Re: Dot 4 or Dot 5

I always use DOT5 in my corvettes. I personally have never had a mushy pedal. The only time I have heard of it being a problem, is in race cars, that have repeated hard braking, and very high temps. I don't think you will ever push your car hard enough to have a problem. Mark

[Stephen L.]

Re: Dot 4 or Dot 5

I agree. Have DOT5 in my classic cars. No problems in 35 years. Pedal pressure is firm in both manual and power brakes and DOT 5 DOESN'T remove paint!!!!!!!!!

[Jim L.]

Re: Dot 4 or Dot 5

I always use DOT5 in my corvettes. I personally have never had a mushy pedal. The only time I have heard of it being a problem, is in race cars, that have repeated hard braking, and very high temps. I don't think you will ever push your car hard enough to have a problem. Mark

THIS IS COMPLETELY FALSE.

My vintage racer and my bride's track car both have DOT5 in their brake systems. The rotors on these cars get so hot they turn blue and develop heat checking. I submit that no one here gets their car's brakes anywhere near as hot as the brakes on our two cars.

NEVER, NOT ONCE, NOT A SINGLE TIME HAVE THE BRAKES ON OUR CARS EVER DEVELOPED A MUSHY PEDAL.

To put a finer point on it, the reason our cars use DOT5 is because DOT5 has superior dry and wet boiling temperatures, not equaled by any DOT3 or DOT4 fluid.

And finally, if your brakes use DOT5 and your pedal is mushy, you didn't get all the air out of the system. It's as simple as that.

[Jim L.]

Re: Dot 4 or Dot 5

That being said, I want to know other’s experiences with regards to pedal “feel” when braking hard.

Jack, to directly answer your question, the pedal feel is superb regardless of braking effort.

[Jack J.]

[Jim L.]

Re: Dot 4 or Dot 5

Cars with ABS can't use DOT5, so the C8 probably uses some form of glycol-based brake fluid.... DOT3, DOT4, DOT5.1

[Richard B.]

Re: Dot 4 or Dot 5

Always used DOT 5. Never had any issues whatsoever. The fluid is non-compressible so any issues with a mushy pedal is likely due to air in the system, poor adjustment or binding.

[Owen L.]

Re: Dot 4 or Dot 5

I wonder if this could be a source of the complaint and welcome any feedback: If there was excessive air entrained in the fluid at install, as if the source container was shaken, would braking heat expand the air bubbles so as to "boil" out of the fluid and become a pocket of air in the system?

I have a Gast vacuum pump and am considering, when filling the new system on my '72, of pulling a vacuum on my DOT5 container before gently pouring it into the M/C just to be sure there's as little air as possible in the fluid.
(DOT 5 for 35 years in my '67 and never a soft pedal issue)