73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: Payton1979Silverado350 on July 16, 2017, 11:27:20 pm
-
I am not very experienced. I recently got my first truck in June ( a 79, 3/4 Silverado 350,4x4). A belt the gose to the air compressor recently started to slip when I have the ac on because is the clutch engaging and disengaging. My father, who doesn't know much at all about cars , suggested a type of spray but I did some research and it would only be temporary. I wanted to ask if I should buy a new belt or if I should just tighten it instead?
-
Check that the pulleys are not oily or greasy and then try tightening the belt. If that doesn't work, a new belt is less than $15 at most auto parts stores and is pretty easy to change with basic hand tools. I'd recommend taking a picture of the routing before removing the old one.
If it was me I would just change all the belts anyways if you don't know how old they are. They're such a simple thing but a pain when they break on you away from home.
-
Tension on V-belts can be a little tricky. There is a tool to get the proper amount of tension, but I have found that the cheapo version of the tool doesn't work that well. A good rule of thumb is that you make the belt nice and taunt without levering the accessory drive too much. Take it for a spin and make sure you turn on the accessories. If is squeals, give it a little more tension. Too much tension can wear things out prematurely, like the bearings in your alternator. What you are looking for is a certain amount of deflection in the mid-span of the belt with a given amount of force applied. Do it a few times and you will get the feel for how tight to make them.
Also...the sheaves that the belt run in (AKA - pulleys) can get burnished from too much slipping. If you have a belt that just keeps slipping no matter what you do, including putting new belts on, it is likely the belt surface of the sheave is burnished and the only way to fix it is to put a new sheave.
-
Would another rule of thumb be, if you can turn the accessory pulley by hand, then it's too loose?