The following will provide you with instructions on how to change the serpentine belt on a 1999 Ford Contour 4 cylinder with a dual overhead cam. I recently changed mine,so I thought I would share the knowledge. This should also apply to 1999 Mercury Mystic 4 cylinder since they are basically the same type of vehicle.
The main problem you will encounter is working space because the serpentine belt is located on the side of the engine on the passenger side.
You can use a socket and ratchet, to take tension off the tensioner pulley which the socket will either be size 12mm or 13mm. The following is a tool that is specially designed to change these belts and will make the job much easier. It will usually come with open ended wrench parts and sockets. You should only need to use the long bar.
You can purchase this tool at most auto parts store or even rent it for the period of time you need it and then return it to receive your money back. I used Auto Zone.
The following is a picture of the serpentine belt:
The belt I purchased was in stock and the average cost was $34.00 dollars. When you go to the store to purchase the belt it is important to know the make and model of your car, the number of cylinders, if it has a dual overhead cam, the engine size, and if it is connected to the air conditioner or if it is different, and year. This will ensure that the store will give you the proper size belt.
One person can do this, but it makes it much easier if you have someone help you. One can place the belt, while the other helps hold the belt in place and apply the pressure needed to release the Tensioner pulley.
It is important to see how the belt is configured before you remove it or have proper diagram for the vehicle you are working on if it is not the specific make and model in this tip. For safety purposes it is also important to remember to let your vehicle cool down completely before attempting to replace the belt due to burn hazards.
You will pull the tool towards the front of the vehicle in order to release the tension. It will not usually take very much pressure to release it enough to remove or replace the belt. Be very careful that you ensure that the proper size socket is used to avoid rounding off the bolt or slippage.
The following is a diagram of how the serpentine belt is configured.
Once you have taken off the old belt and started to replace the new one, you must ensure that the belt's grooves fit properly on each pulley and that it is not overlapping. The grooves on the belt should align with the grooves on the pulleys. I found it easier to get all the lower pulleys first and then worked my way up. I put the belt under the idler pulley last as pressure was applied on the tensioner pulley.
GEN=is the alternator.
TEN=is the tensioner.
WP=is the water pump.
PS=is the power steering.
A/C=is the air conditioner.
IDL=is the Idler pulley.
Things you want to look for to give you an idea of when it is time to replace your belt are: Cracks, Tears, the car squeals when you first start it because the belt is slipping, Dry Rot, the grooves are worn down or have tears in them, etc.
I hope this tutorial will help you fix your serpentine belt with ease.