Next time you utilize a drive belt, timing belt, or timing chain, you’ll likely need to loosen a tensioner pulley to remove it. Following these general recommendations and specific instructions from your own owners manual or repair manual, your belt or chain will function for the life span of your car.

Toyota and other timing belt tensioners are loosened by simply removing them from the engine. You must slowly compress them in a bench vice and lock them with a pull-pin before reinstallation.
Hydraulic (not hydraulic-damped) tensioners are nearly always located in the timing case, mostly upon automobiles with timing chains, though some are used with timing belts. Hydraulic tensioners are run by oil pressure from the engine oil pump and could press on a tensioner pulley (timing belts) or stress slipper (timing chain). You’ll likely need the year, make, and model information, and you may need to use special tools for this sort of tensioner pulley.
Typically, a hydraulic tensioner must be “reset” and locked after removing it from the engine. Remove the lock only after the tensioner, pulley, or slipper, and timing belt or timing chain are installed 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 maintains drive belts from slipping and making sound. To loosen a drive belt springtime tensioner pulley, refer first to the repair manual or owners manual’s specific year, make, and model details.
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 correct tool, release stress on the belt. You’ll need to hold some spring tensioners while slipping on a new 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. Push the pulley toward the additional pulleys or accessories, loosening the belt.
Spring tensioner pulleys, as the name implies, make use of a spring to hold tension on the belt. Most, if not all, springtime tensioner pulleys are NAI tensioners you need to include a hydraulic damper. They are more complex and Car Pulley Belt expensive but don’t require changes and are less susceptible to user error.