I'll do what I can, but don't get your hopes up.

我会尽力而为的，但别抱太大希望。

《牛津词典》

For the iPad 2, don't get your hopes up too high.

对iPad 2，别把希望抬得太高。

youdao

But don't get your hopes up.

但是不要期望太高。

youdao

They make a nice couple, but don't get your hopes up for a "Thin Man"-like series.

CNN: Review: 'Gone Baby Gone' is good, very good

Don't get your hopes up for a tie-in on the level of VW's iPad-friendly Bulli concept, however.

ENGADGET

But like miracle diets and great blind dates, don't get your hopes up.

FORBES: Overview