Originally Posted by JTeamtech

Yip- that is it. Often also can recover a liner that has been overheated.
You can experiment with slightly higher temps than a domestic oven if you have access to an autoclave or similar.

Do not use direct flame. Stick it in the oven for 20-30 minutes then let the sleeve cool naturally in the oven or out but do not quench. It basically relaxes some of the stretch put in by the heat cycles.

Especially useful on a mother that has just lots that 'edge'