Serpentine Belt Replacement at Auto Service Experts Complete Auto Shop
Drive Belt, Serpentine Belt or V-Belt Replacements & Maintenance in San Antonio, TX
The red arrows in the above photo show the serpentine belt as it snakes around external engine component pulleys.
Serpentine Belt Replacements & Inspections
The serpentine belt is a drive belt (also called the accessories or fan belt) which transfers power from the engine to external automotive components or accessories which run on it. Many modern vehicles rely on one belt to run the alternator, auto air conditioner compressor, power steering pump, and possibly the water pump or power brakes. Some models (including some BMWs, Fords, and Nissans) have a separate serpentine belt which runs the air compressor. Most manufacturers recommend specific belt replacement intervals, but they should also be inspected yearly for misalignment issues and signs of premature wear. It is important to identify maintenance issues such as a cracked belt, bad tensioner, or worn pulleys before they lead to complete failure. If the belt breaks, all of the components which run on it will stop. More importantly, these components and the engine itself can be severely damaged.
Serpentine Belt Problem Signs
Serpentine belt failure is a part of normal wear on your vehicle. Over time, the belt will begin to stretch, crack and break down. There are many possible signs of serpentine belt problems which let you know it is time for a replacement before it fails completely. In some cases, the particular symptom you are experiencing may give you some insight into what exactly is causing the problem. For Example, serpentine belt slipping may cause a "squealing" sound while accelerating or on a cold start and may lead to polished belt edges or grooves. If there is a misalignment in an accessory drive pulley, you may hear a "chirping" sound or see that the belt is frayed on the edges. A misalignment of the pulley or belt may cause the belt to come off. Damaged bearings in the idler pulley, tensioner pulley, or a driven accessory can cause a "whirring" or "grinding" sound. Coolant, power steering fluid, or oil leaks can drip onto and contaminate the rubber belt making it dirty or slippery and causing it to break down sooner.
FREE Diagnostic With Repairs!
While some of these problem signs are easily recognized, others require a visual inspection & possibly belt removal to spot. In any case, it is a good idea to have any issues diagnosed by a qualified mechanic who can determine not only the extent of the damage but also the exact cause of it. The ASE Certified Master Mechanics at Auto Service Experts have over 20 years of experience replacing serpentine belts and V-belts on all makes and models of vehicles. If you are unsure which system your vehicle operates on, or have any questions about maintenance requirements for your particular car, truck, or SUV, give us a call and one of our friendly automotive service consultants will be happy to help.
This display diagram shows the belt wrapping around (clockwise from top left) the power steering pulley, alternator decoupler pulley, water pump fan pulley, idler pulley, crank pulley harmonic balancer & belt tensioner.
Tip - Some people are tempted to apply belt dressing thinking it will be a quick DIY fix for slipping or squealing, but this will worsen the problem. The sticky dressing spreads into pulley groves attracting dirt. The belt will still have to be replaced and the repair will be much more labor intensive (therefore more costly) than it otherwise would have been.
Belt Tensioner Replacements
Belt tensioners maintain the proper tension on the serpentine belt. If the belt is too loose it does not properly transfer power to the components which rely on it, and it can begin to slip or come off entirely. A belt which is too tight may snap or break. Many tensioners are either spring loaded or rely on hydraulic pressure to maintain tension. Others must be manually adjusted. Belt tensioner replacements are a part of routine car maintenance and help to keep the belt and the components which rely on it running smoothly.
Tensioner Pulley Replacement
If the tensioner pulley malfunctions, it may be possible to replace it without replacing the tensioner depending on the year, make, and model of your vehicle. Many times, however, these parts are not sold separately so it makes sense to replace them both at the same time.
Idler Pulley
The function of the idler pulley is to direct the belt around different components, maintaining tension and keeping it out of the way of other components.
V-Belt Replacements
V belts are a different type of drive belt (also called fan belts or accessory belts). These were used mainly on older vehicles before the introduction of the serpentine belt and are still used today on some models. They are a series of belts which transfer power from the engine to external components. In most cases, they run from the crankshaft to an individual component. Together, V-Belts serve the same purpose as a serpentine belt. Serpentine belts are wider and flatter and usually run on 3-8 grooves. A v-belt system uses multiple smaller, thinner, 1 groove belts to power the same components.
V-Belt Problem Signs
V-belt failure can occur as a result of natural wear and tear as the rubber breaks down over time and pulleys become worn, damaged, or misaligned. Because failure can lead to other types of engine problems including timing belt damage, it is important to follow the manufacturer recommended schedule for v-belt replacements. Warning signs include unusual noises such as "chirping", "squealing", "grinding" or "slapping", as well as vibration. Upon inspecting the belt you may find that it is hot to the touch, cracked, worn, frayed, swollen, or hardened.
V-Belt Failure
Premature failure is most often caused by lack of maintenance. Proper maintenance involves periodic inspections to check for misalignment, worn pulleys, or malfunctioning tensioners. Environmental factors such as extreme heat and dirty, dusty, or contaminated air can also cause the belts to break down much faster than normal. In other cases, improper installation, defects, or design flaws particular to certain vehicles can cause failure.
