Cause
The hydraulic oil level is too low.

Solution
Add hydraulic oil.

Cause
The tensioner seal is defective.

Solution
Replace the tensioner seal.

Cause
There are micro-leaks in the hydraulic system of the tensioner.

Solution
Inspect the hydraulic fittings of the tensioner system to find any possible leaks. Small balls of sawdust will form where micro-leaks are present.