My right speed brake just started to be slow to retract (after a Colorado cold snap). They both deploy fine. I believe they are vacuum type since it’s a1988 m20k and they only work with the engine running. Does anyone know if the vacuum retracts or is it strictly cable or spring? Do they run off the engine driven pump? I also noticed my vacuum gauge took about five minutes to get in the green. Normal? Problem looming? Even when engine driven pump was in the green the right brake would not retract normally.( very slow) I’m working hard on Ifr currency and expect to be flying in imc soon. Don’t want any surprises. Help!