break light coming on when changing gear

[truckarms]

Hi Guys,
I cant work out whats going on but when I change gear from 1st to 2nd and sometimes from 2nd to 3rd I get the hand break light coming on.
It happens every time in first does not matter if I accelerate hard or not but only happens in second if i push the car hard.
I checked the brake fluid and it looks fine, but apart from that I cant work out why it keeps coming on.
Very confused any ideas would be great thanks.

[BUSHWHACKER]

Hi Guys,
I cant work out whats going on but when I change gear from 1st to 2nd and sometimes from 2nd to 3rd I get the hand break light coming on.
It happens every time in first does not matter if I accelerate hard or not but only happens in second if i push the car hard.
I checked the brake fluid and it looks fine, but apart from that I cant work out why it keeps coming on.
Very confused any ideas would be great thanks.

Dunno about the 4Runner, but the brake indicator light is also a low or loss of vacuum warning on the Surf.