Do most people use dot 3 or dot 5 brake fluid ? i thought if you use classic dot 3 brake fluid, you should change brake fluid every 3 years. I will be honest, I never change fluid unless I am fixing a brake issue.
This is probably heresy to most but I have never changed brake fluid as a maintenance item. Only if there was a problem with the brakes like a soft pedal and only after bleeding didn't fix it, but the latter has never happened. Bleeding seems to always fix it. I guess if you bleed the lines enough you have effectively replaced the fluid.
Don't know if it is right or wrong just me, Chet..
Side Note: With all of my old cars the brakes are the first thing I fix which usually involves replacing lines, cylinders, and rebuild the master. So after all that new fluid is normal for me but not an ongoing maintenance item.
Rebuilt the master cylinder, wheel cylinders and new rubber brake hoses. Fresh DOT-3 and never gave it another thought.
When I had my wheel cylinders rebuilt and had to do all new fluid, I went with Valvoline Dot 3/4 synthetic since it was on sale at the time.
Hi Guys,
Dot 3 & 4 brake fluid are hygroscopic therefor absorb moisture from the atmosphere whether being used or not, and is the cause of cylinder failures and brakes requiring bleeding due to bad fluid. If you have cars under 6 year old this will not be an issue for you, but for the next owner.
Industry standard is to suckout the reservoir and flush fluid every 2 years on modern cars which have good sealing reservoirs.
(our fire department service brake fluid yearly).
I use dot 5 silicone fluid ( as used by Harley Davidson ) in my Q and my trailers, it does not absorb much (if any) moisture (so does not require regular replacing) and does not eat/damage paint work if you make a drip. My understanding is that dot 5 can not be used with ABS cars or any assisted disc brakes.
Dot 3 or 4 in daily drive cars, mine are 80's & 90's cars.
My 2 cents worth,
Des .
Hi again,
Here is a not to technical link on brake fluids.
http://www.restore-an-old-car.com/classic-car-brake-fluid.html
Des .
I guess I will stay with dot 3. I never had luck with a one man bleeder.. I always use a teenager as the brake pedel pumper. :)