Replacing the Serpentine Belt – How to Do It as a Beginner

Replace Serpentine Belt

What is oftentimes underrated when it comes to vehicles and also keeps vital components working is a part called a serpentine belt. This type of belt is snaking, long and winding in order to keep the steering pump, alternator, air conditioning and at times the water pump working effectively.

Whilst back in the day a vehicle had a lot more belts for each component and each one of them could be replaced when needed it wasn’t a very useful system, performance-wise.

With a serpentine belt, this issue was solved once and for all but like its predecessors, this belt also needs to be replaced. This type of car repair usually happens every 50,000 (80,467 km) to 100,000 miles (160,934 km) but other visual cues can also determine whether or not you need a new serpentine belt.

How to Check If You Need to Change It

Check the BeltThe best way to determine whether or not you need to actually change the serpentine belt is to measure with a gauge. Press in the gauge into a groove of the belt and if you have it sitting above the ribs that means the belt is in good shape.

If the gauge sits even with the belt then it needs to undergo a serpentine belt replacement. You can also check the roller/ pulley and tensioner but that does not help determine the state of the belt rather the function of the surrounding components.

How to Replace The Serpentine Belt

What You Need

Tools to change do the jobFor this DIY auto repair, you’ll need a serpentine belt tool, serpentine belt replacement tool and a tensioner (if needed). The serpentine belt tool has a number of different sockets and two extension bars.

These bars allow you to reach the tensioner at the correct angle. You also have an extra-long handle which allows you to release the pressure of the tool more easily. You’ll also need to inspect the decal that has the belt routing on it.

This will give you a clearer image of the whole area.

How To Do It

Change Serpentine BeltGet your serpentine belt tool and rotate the tensioner with it in order to remove the tension from the belt. Then remove the belt from all the pulley’s and slowly release the tensioner.

Place the new serpentine belt with the serpentine belt placement tool. Route the new belt through the path shown on the decal. Then, rotate the tensioner again whilst loading the belt around it.

Make sure you wrap the new serpentine belt around the crankshaft pulley too and then around the grooved pulleys. You should finish placing the new belt by sliding it onto a non-grooved rounded roller.

Make sure to double-check the alignment of the belt regarding all the pulley’s and also the path which is shown on the decal. When you’re done slowly release the tensioner again.

Signs That You Need A New Belt


Noise Serpentine BeltIf you are hearing a lot of squealing it means that there is a lot of wear on the belt. This squealing noise happens because the belt is slipping and it only occurs the first couple of seconds when the engine starts working.

After that the squealing stops but if the belt is slipping regularly it can mean that it has glazed grooves and polished edges too. This is a strong indicator that you need to replace it.

A squealing belt can also occur if it gets wet from liquids such as the coolant or power steering fluid. If you have rainwater on the belt that has been collected by the pulley wheels your belt is not in danger.

Wear & Tear

Wear Serpentine BeltIf your vehicle is using an older type of serpentine belt it will be more prone to having big chunks fall off from it than today’s EPDM belts.

While the majority of belts will still function properly even if they have some pieces missing, they still won’t last for much longer when more chunks are going to start falling off.

The same goes for cracks if there are small ones on the top surface of the belt it’s not that big of a deal. But if the cracks are deep, like halfway through the belt you definitely need to change it.

Otherwise, you are ruining the risk of the belt breaking. Loss of material from the belt can also be the result of a misaligned pulley wheel which can make the rubber from the belt collect in between the grooves and dull the otherwise sharp edges.

If the belt is worn out unevenly it is possible that the belt is misaligned.

Low Battery

Discharged battery warning light in car dashboardAlthough this is not something directly associated with the belt, if your vehicle’s battery cannot maintain a full charge it can be a fault with the serpentine belt. This usually happens when the belt running the alternator is slipping a lot.

This can reduce the electrical output from the alternator causing the charge sent to the battery to be uneven. A low battery can confuse the computer in the vehicle which will result in unpredictable performance and various warning lights may start to appear too.