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

Toyota and other 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 nearly always located in the timing case, mostly on automobiles with timing chains, though some are used with timing belts. Hydraulic tensioners are Car Pulley Belt powered 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 will likely need the entire year, make, and model information, and you may need to use special tools for this kind of tensioner pulley.
Typically, a hydraulic tensioner needs to 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, while the hydraulic damper keeps it from bouncing under load changes. This prevents timing belts and timing chains slapping and jumping teeth and will keep drive belts from slipping and producing noise. To loosen a drive belt springtime tensioner pulley, refer initial to the restoration 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 appropriate tool, release tension on the belt. You’ll need to hold some spring tensioners while slipping on a fresh belt. Others may possess a locking mechanism, like a hole for a locking pin or hex important.

To loosen an NAI tensioner, loosen the locking nut or bolt, then back off the tensioner screw. Drive the pulley toward the additional pulleys or components, loosening the belt.
Spring tensioner pulleys, since the name implies, use a spring to hold tension upon the belt. Most, if not absolutely all, springtime tensioner pulleys are NAI tensioners and include a hydraulic damper. They are more technical and expensive but don’t require adjustments and are less susceptible to user error.