Seeing how you should begin the renewal process at least one month before your residence permit expires, I don't see how your employer would not know your intentions.
Since you will be completing your contract, I can't imagine why they wouldn't help you get the visa if they are a legitimate school, albeit you need to factor in laziness and incompetence on their part. If you've been working for them for a year, you should already have a good idea on how they operate.
If all else fails, you can go to the PSB yourself and apply in person, but you might still need documentation from your employer. As a last resort, you might be able to apply for a tourist visa in HK but I have no experience with that.