IFR emergencies

IFR Vacuum Failure
The Cessna 182S POH (actually all the new Cessna manuals say pretty much the same thing) also covers emergency operation in clouds where a total vacuum system failure is suspected and "the pilot is not completely proficient in instrument flying.
Executing a 180 degree turn in clouds: "Upon inadvertently entering the clouds, an immediate plan should be made to turn back as follows:
1. Note the compass heading.
2. Using the clock, initiate a standard rate left turn, holding the turn coordinator symbolic airplane wing opposite the lower left index mark for 60 seconds. Then roll back to level flight by levelling the miniature airplane.
3. Check accuracy of the turn by observing the compass heading which should be the reciprocal of the original heading.
4. If necessary, adjust heading primarily with skidding motions rather than rolling motions so that the compass will read more accurately.
5. Maintain altitude and airspeed by cautious application of elevator control. Avoid over controlling by keeping the hands off the control wheel as much as possible and steering only with rudder."

IFR Emergency Descent
The procedures for an emergency descent through clouds are similar, using power to set up a 500 to 800 ft/min rate of descent, trim for 80 KIAS and keeping the hands off the control wheel, steering only with the rudder, using the compass for maintaining heading rather than the gyro. Recovery from a spiral dive into the clouds involves retarding the throttle to idle, using rudder and aileron to level the wings of the artificial plane on the TC, cautiously reducing airspeed to 80 KIAS, then keeping hands off the control wheel and steering using only rudder. Clear the engine occasionally, but avoid using enough power to disturb your trimmed glide. On breaking out of the clouds, resume normal flight. For these two procedures Cessna recommends maintaining a heading of W or E in order to minimize compass error.

Emergency Use of Turn Coordinator

Best to do considerable "rudder only' flying
Centre the turn needle with the rudder and keep it centred using only rudder
Hands off the flight controls.
Lower the landing gear.
Reduce the power above a high idle.
Trim to its predetermined airspeed.
Propeller pitch full forward
Power to the predetermined setting.
Expect airspeed oscillations
Check the compass heading.
Turn with the rudder.
Roll out on the desired heading using lead or lag if relying on a magnetic compass
Altitude is changed using power supplemented by rudder pressure to maintain heading