Brake Fluid Low and Brake light

The temperature is below freezing in the morning now. The Brake Fluid Low light and the Brake light are on in the morning. As the temperature warms up the lights do not come on. What could be causing this problem? Could the float that indicates the brake fluid level be sticking when it is cold? Thanks

Things are warming up during the day and expanding which is causing the indicator trip point to change. Add a little brake fluid.

Things are warming up during the day and expanding which is causing the indicator trip point to change. Add a little brake fluid.

To add to this point, as the front pads wear, the pistons in the calipers move further out of the bores in the calipers.

To compensate, the space created fills with fluid from the master cylinder.

If the front pads are near the end of their useful life, it might be wise to pull the front wheels and check to see how much material is left on the pads.

If there are less than 1/8" of material left, replace the pads, and before attempting to bottom the piston, open the bleeder on the caliper, and with a piece of clear tubing attached to the tip of the bleeder screw, running into a coke bottle or suitable container partially filled with brake fluid (this effectively prevents air from being sucked into the caliper while you are fussing with the piston), force the old fluid out through the bleeder.

I think 'crdu' is the one who taught me this move. Makes sense too as you do not want the old fluid (moisture, rust and other contaminants will be mixed with the fluid) going back up into the master cylinder.

Top the master cylinder up after replacing the pads, and re-installing the calipers.

if you add brake fluid between pad changes remember to take it back out before the next pad change or you could blow the top off of the master cylinder ...seen it done..