Thread: Hard Acceleration - Brake Fluid Warning Light

Occasionally, upon hard acceleration I have gotten a brake fluid warning light. This makes sense as the fluid might drop away from the sensor depending on where it is placed.

However, it has gotten more frequent lately and now it just comes on when I start the car up. I check the fluid and the reservoir is about half full. I thought about topping it off but didn't want to open a large bottle of fluid only to top off the reservoir since it expires. I'd like to flush the system while I'm at it.

Just curious if anyone has thoughts on what may be occurring. Maybe I should be looking for a leak in the system somewhere as the fluid could be dropping slowly and now it is to the point where it is tripping the sensor?

Thanks,

Joe

Ok thanks.

I bet one of your rear calipers is leaking near the ebrake mechanism.

fill your master cylinder res, its low and making the light come on when the fluid moves away from the sensor. you either need new brakes really bad, or you have a leak for the level to get that low.

As your brake pads wear, they get smaller. Thus more fluid remains in the caliper, and the level in master drops SLIGHTLY over years, probably. Brake fluid sensor is under the reservoir. Simple small plastic part, goes for about $5, takes less than 5 minutes to swap out.


BTW: they do go bad, just changed mine this year. You don't need to bleed or flush just to change the part, only if you feel the need.

Ok thanks for the ideas guys!

^^^Definitely what Cheatah Faheatah said...

As your brake pads wear, they get thinner. As they get thinner, the caliper sticks out more. This displaces the fluid in the reservior.

Check your brake pads first. If they are worn, replace them. The light should go out then...

I'm aware of the pad wear vs fluid level relationship. I believe the fronts are good but I'll check them all anyway. I'll probably investigate in this order:

Check for leaks
Check pads
Top off fluid
Replace sensor (unlikely)