Next time you utilize a drive belt, timing belt, or timing chain, you’ll likely have to loosen a tensioner pulley to remove it. Subsequent these general recommendations and specific guidelines from your owners manual or repair manual, your belt or chain will function for the life span 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 before reinstallation.
Hydraulic (not hydraulic-damped) tensioners are almost always located in the timing case, mostly upon automobiles with timing chains, though some are used in combination with timing belts. Hydraulic tensioners are driven by oil pressure from the engine essential oil pump and may press on a tensioner pulley (timing belts) or pressure slipper (timing chain). You’ll likely need the year, make, and model info, and you may have to use special tools for this type 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 set up and aligned.

The spring maintains tension, as the hydraulic damper keeps it from bouncing under load changes. This prevents timing belts and timing chains slapping and jumping the teeth and keeps drive belts from slipping and producing noise. To loosen a drive belt spring tensioner pulley, refer 1st to the repair manual or owners manual’s specific yr, 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 spring tensioners while slipping on a fresh belt. Others may have a locking mechanism, such as a hole for a locking pin or hex important.

To loosen an NAI tensioner, loosen the locking nut or bolt, after that back off the tensioner screw. Drive the pulley toward the additional pulleys or add-ons, loosening the belt.
Spring tensioner pulleys, because the name implies, use a springtime to hold tension on the belt. Most, if not absolutely all, springtime tensioner pulleys are NAI tensioners you need to include a hydraulic damper. They are more complex and costly but don’t require modifications and are less prone to user error.