When you change the oil you need to follow 2 steps:
1) Prior to the change: check the correct grade of oil that your truck uses, how much oil and the correct oil and filter. Also you need to know where the oil fill cap is, oil drain plug and where is the oil filter. Also you need to know where the drain plug of the transmission (automatic or manual) is so you won't get confused. Have the wrench for the plug in hand, a funnel, rags (for cleaning) and maybe an oil filter wrench.
2) When you change it: open the oil fill cap, take out the oil dipstick, place a container that holds more than the capacity of the oil your taking out under the truck and take out the oil drain plug with the wrench first then with the hand not letting the plug get in the container. Wait until all the oil is draining and replace the oil filter with a new one (apply a thin layer of new oil to the filter gasket befor installation )
Clean the plug and put it back, tightening with the wrench. Using the funnel add the recommended amount of oil. Replace the fill cap, and the dip stick (after cleaning it).
Start the truck, check for the oil indicator in the dash, it should be on for a few seconds then off, it's normal. If stays on the pressure is low and you have done something wrong, maybe too little oil or the filter is loose...
After the light goes off step on the gas several times and after a couple of minutes switch off the engine. wait 5 minutes and check the oil in the dipstick, it should be between the min and max points.
If you did this when you changed the oil the problem is somewhere else, if you're not sure check with a mechanic to see what went wrong.
Hope this helps...
