Can I bypass the in-dash vacuum?

[crazytooguy]

Hello all. On my 1997 S90, I have the classic vacuum servo leaking problem, and I'll dig into the dash and replace it eventually, but for now, the vacuum is bad enough that the heater control valve won't close all the way, dumping heat in the middle of summer. So, according to the diagram in this thread (viewtopic.php?t=82337), can I bypass all the interior control stuff (connect line 29 to line 30) and directly connect the manifold vacuum to the heater control valve? That way, I'm not heating up the interior until I can change the vacuum servo.

Thanks!

Pat