We are getting ready to put brake fluid in the Cuda. It is a original owner numbers matching 440 6bbl 4sp. It has all new brake components. It will be driven once or twice a month. The owner wants me to put DOT 5 fluid in it because of worry about long term hydroscopic problems and the remote chance of DOT 3 or 4 getting on the paint. What do you guys use?

that sounds like an excellent candidate for DOT 5

Been running DOT 5 for years...


No way I'd go back to DOT 3...


Your paint will thank you...



HOWEVER, silicone brake fluid keeps water in suspension...


Got to keep an eye on it...


Since silicone fluids do not absorb moisture, systems using silicone must be flushed and maintained at more frequent intervals than glycol-based fluids. The typical life expectancy of glycol-based fluids is about two years. As the moisture content of glycol-based fluids increases with time and exposure to atmosphere, the color changes from light clear or amber to a darker brown color. Local climate will impact the life cycle of fluid, based on average humidity

This is my favorite subject, along with cone type sure grips and pinion angle.

I've been running DOT 5 for 20 years in 1 vehicle, 15 years in 3 different vehicles, and have NEVER had a problem. Also, I have never changed any of it. If you have a race or toy vehicle, I would use nothing else.

Use the DOT 5 and never worry again. We use it in older postal vehicle with no problems.

Dot 5 over 25 years, no issues.
Doug

I can't get dot 5 to seal up and quit leaking.

I run Dot 5 and haven't had any issues with leaking? It did take a while to get properly bled (but that said, I have 8 piston front and 4 piston rear calipers) but no drips or leaks anywhere. (flex lines were all new, hard lines were half new and half older)

(I see yer stirrin' it up in Conn...


Outlaw...)

I use DOT4 conventional... and have had to touch up the new paint on the fender liner from a leaking MC lid. Unfortunately, the art of getting re-pop older style MC lids to seal seems to have been lost. Water issues can be controlled by changing the fluid every couple of years. That said, I think, the silicone DOT5 makes sense in your situation. There are lots of posts on bleeding... I think it comes down to settling. Let the fluid settle in the bottle before pouring it in and bleed a couple of times with settling time in between to get the bubbles together and out.

Every season I crack the bleeders and change the fluid out a few pumps..Most all the moisture problems with dot5 are the wheel cylinders and calipers..Other than that I have'nt seen any downside to using it...

We have used DOT 5 for 20+ years in multiple vehicles. No problems what so ever and we have not changed any out either.

Thanks everyone. Put the DOT 5 in the car last night. None of the parts stores around here had it in stock so had to order it. Came from wharehouse in a couple of hours. Bench bled the master cylinder. Vacuum bled then gravity bled the brakes. The pedal is great no paint problems.