Car Fix DIY Videos

How to replace both the AC and Serpentine belts on a 2012 Mazda 3 i, without any special tools. To replace the serp, you must remove the AC belt. There are many ways to do this, I personally cut the AC belt off.

The serp belt is easy to remove and install due to the tensioner. The AC belt is not difficult to install but requires one of several methods – either a special tool, strong hands, lowering the AC compressor, or using zip ties. I chose to use zip ties and had no issues with the installation; if the belt is off by a few groves, simply push it as it guides onto the AC pulley.

Do be sure to buy strong zip ties. I used 45 lb strength, tried with only four, and if you watch closely, the first set of four broke. On the second try, I attached four, walked them up from about 3:00 counterclockwise to 12:00, then put four more on the next slot for a total of 8; these worked well. The zip ties will be tight against the serp belt and the AC belt, so loosen the serp to easily get all zip ties removed once installation is complete. Tighten the serp, and you should be good to go!

Saved over $150 on this job compared to a mechanic in Boston…complete time should be well under an hour with the right parts and tools, listed below.

Parts:

Bando 6PK1305 – 1305mm (51.2in) OEM Mazda 3 Serpentine Belt
Gates K050264SF – 27in OEM Mazda 3 AC Belt

Tools:

14 mm socket (Tensioner Pulley)
21 mm socket (Lug nuts and crankshaft)
12 mm socket (AC heat shield)
10 mm socket (Splash Guard)
Phillips Head (Splash Guard)
1305mm / 51.2in Belt (Serpentine)
27 in Belt (AC)
Zip Ties (8 45lb tensile strength ties worked for me)
Needle Nose Pliers (To remove zip ties)
Torque Wrench
6″ Socket Wrench
Scissors
Jack
Jack Stands