What would cause the light to be on if the reservoir is full? It mostly comes on when going up a hill or making a hard turn. Anybody know where I should start checking? Also the connector seems snug.

 

The Brake light also comes on with the parking brake. It can also come on if the alternator stops working.

But based on your stated symptoms (hill, hard turns) I would guess you have a water(fluid?)-logged float in the brake fluid reservoir, or a bent hangar. Just remove the cap and gently press down on the float. I can't tell you how many mm it SHOULD move before illuminating the light, but it should be at least the spacing between the "full" and "add" lines. If it's only a mm or 2, there's your problem.

 

Ok will check that. Thanks.

 

On my son's 2000 Tacoma the brake light kept coming on. I greased the parking brake cable and it fixed it. Five minute repair.

 

Where exactly did you grease it? Thanks.

 

Whenever I release the parking brake I always have to give the handle a little shimmy and shake to get the light to go out!

 

If you crawl under it will be obvious. There's a brake cable running to the rear. Take your bottle of spray grease when you climb under and it takes a minute.

 

+1
most likely this ^^^

But also check your e-brake sensing switch, in case it is just so slightly out of adjustment.

 

As 89fourrunner says, "testing" the e-brake sensing switch (at least on the first go) is pretty easy. No need to climb under the truck until you determine it's the culprit.

What if shaking the parking brake lever makes the light go out? What do you do? All answers are found in The Good Book: http://web.archive.org/web/201102052.../6combinat.pdf