The next time you work with a drive belt, timing belt, or timing chain, you’ll likely have to loosen a tensioner pulley to eliminate it. Subsequent these general suggestions and specific guidelines from your own owners manual or restoration manual, your belt or chain will function for the life of your car.

Toyota and additional timing belt tensioners are loosened simply by removing them from the engine. You need to gradually compress them in a bench vice and lock them with a pull-pin Car Pulley Belt before reinstallation.
Hydraulic (not hydraulic-damped) tensioners are nearly always positioned in the timing case, mostly on vehicles with timing chains, though some are used with timing belts. Hydraulic tensioners are run by essential oil pressure from the engine essential oil pump and may press on a tensioner pulley (timing belts) or stress slipper (timing chain). You’ll likely need the year, make, and model details, and you may have to use special tools for this kind of tensioner pulley.
Typically, a hydraulic tensioner must be “reset” and locked after removing it from the engine. Remove the lock only following the tensioner, pulley, or slipper, and timing belt or timing chain are set up and aligned.

The spring maintains tension, while the hydraulic damper keeps it from bouncing under load changes. This prevents timing belts and timing chains slapping and jumping tooth and continues drive belts from slipping and producing noise. To loosen a drive belt springtime tensioner pulley, refer first to the repair manual or owners manual’s specific calendar year, make, and model information.
You may need a special tool, but many spring tensioners have a square hole, for a 3/8” or 1/2” breaker bar, or a hex or square protrusion for a wrench or socket. Using the appropriate tool, release stress on the belt. You’ll need to hold some springtime tensioners while slipping on a fresh belt. Others may have a locking mechanism, such as a hole for a locking pin or hex crucial.

To loosen an NAI tensioner, loosen the locking nut or bolt, after that back off the tensioner screw. Press the pulley toward the various other pulleys or accessories, loosening the belt.
Spring tensioner pulleys, because the name implies, make use of a spring to hold tension upon the belt. Most, if not all, springtime tensioner pulleys are NAI tensioners you need to include a hydraulic damper. They are more complex and costly but don’t require adjustments and are less prone to user error.