I thought I would do my VTR a favour and flush the brake/clutch fluids. I am 62 yrs of age and as usual, assuming I was still young, I did not wear my eyeglasses. In this deficient state I could not see the tiny DOT 4 warning on the reservoir caps, and used DOT 3. Since I did a vacuum of the reservoirs and flush of the remaining parts of the system is there a problem? I read somewhere that mixing 3 and 4 COULD, no would cause corrosion. Comments?