The brake warning light comes on and stays on after the truck has started. It stays on for a couple of minutes and then goes out. Then when I either put the truck in gear (Automatic) and use the brakes the light comes on and stays on for a couple of minutes then goes out. The fluid levels are fine. I just had new brakes put on a couple of months ago, but this problem didn't start until a couple of weeks ago. Any ideas.

The ABS light does not come on. I have trailer brakes hooked to the cold side of the brake switch.

 

I had the same problem with my 97 and it turned out to be my vaccume pump. I don't know if the brake warning light is hooked right to the pump or not but after it was fixed the light never came back on.

 

Thanks.. Thats what it appears to be. Have it down at the shop now. The vacuum test showed about 15 pounds.
I forget what it should have showed. Thanks again for your advice. Had some folks giving me all sorts of different ideas, parking brake cable too short etc;

 

Remove the fuse for the ABS.

ABS on these sucks, it causes the brakes to lock up all the time.