[SS427]

I used to use silicone exclusively on my restorations due to the effects of Dot 3 on painted surfaces. However the companies that reline master cylinders and wheel cylinders will no longer warrant their work if you are using silicone so that alone has forced me to switch back. The other issue is because of the viscosity of silicone it is VERY prone to leaking no matter how tight you think you may have some joints. Since going back to Dot 3 I have not had an issue. I just have to be a LOT more careful during the bleeding process. I have never used DOT 4 so I cannot add to Mk IV's comments.