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

Toyota and additional timing belt Car Pulley Belt tensioners are loosened simply by removing them from the engine. You must 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 upon automobiles with timing chains, though some are used in combination with timing belts. Hydraulic tensioners are 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’ll likely need the entire year, make, and model info, and you may have to use special equipment 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 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 teeth and continues drive belts from slipping and producing noise. To loosen a drive belt springtime tensioner pulley, refer first to the restoration manual or owners manual’s specific 12 months, make, and model information.
You might 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 pressure on the belt. You’ll need to hold some spring tensioners while slipping on a fresh belt. Others may possess 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. Drive the pulley toward the additional pulleys or components, loosening the belt.
Spring tensioner pulleys, as the name implies, make use of a spring to hold tension upon the belt. Most, if not all, springtime tensioner pulleys are NAI tensioners and include a hydraulic damper. They are more technical and expensive but don’t require modifications and are less susceptible to user error.