Brake Fluid Dot 4??

[mjfeeney4]

I just had to have the master cylinder replaced and the mechanic claimed I had used the wrong brake fluid (silicone based). Have used the Ute DOT 4 brake fluid for a fluid flush and used the blue color, to tell when the older red fluid had been displaced. Should I be using DOT 5 fluid??? The Bently manual lists DOT 4 in the specifications. Now I'm wondering if the fluid might have caused a failure of the seals or o rings in the master cylinder.

[Bill R.]

ATE super blue is silicone based. Its not. Its a dot 4 and dot 3 compatible regular fluid and wouldn't have caused your seals to fail. No, you shouldn't be using a dot 5 in your car. I have been using the ate fluid for years...
Now when you mention red fluid I'm not sure what your talking about. Most brake fluid is amber colored like honey or even a little more clear and when it gets old and contaminated its a dark brown.





I just had to have the master cylinder replaced and the mechanic claimed I had used the wrong brake fluid (silicone based). Have used the Ute DOT 4 brake fluid for a fluid flush and used the blue color, to tell when the older red fluid had been displaced. Should I be using DOT 5 fluid??? The Bently manual lists DOT 4 in the specifications. Now I'm wondering if the fluid might have caused a failure of the seals or o rings in the master cylinder.

[mjfeeney4]

Bill; You were right a while back when you suggested my brake locking problem was caused by the master cylinder. My only regret was not replacing the MC myself. The dealer tried to charge me $220 for a complete brake fluid flush, suggesting the the Ate Racing Blue may have caused the problem. Also wanted to rreplace the rear calipers, rotors and pads as well ( another $1200) but I didn't go for it.

[winfred]

i am also drawing a blank on the red fluid, i find dot 3 is to blame for turning the rubber grommits to jello, when ever i have to change them i check the trunk and find a bottle of dot 3, dot 3 will usually seriously screw up a british cars brakeing system also, i think it has alcohol in it and that eats up natural rubber