Putting the wrong direction pump on would not cause the any significant
problem. The engine still turns the same way. It is just a factor of pump
longevity. The other post speculating that the lines were hooked up backwards
is more serious if that occured. The suction regulator is not designed to let
out air, it lets it in to regulate suction. Reversing the lines could seriously
"over-boost" the gyros. I agree if this is the case, talk to an instrument
shop. The key question is what did the suction gauge say. If it read zero
during the run, bad problem, hoses were reversed. If it read normal 5.0-6.0
inhg then no damage done. But you probably have a worn out DG. (I have had DGs
spin around when they start to fail.)
Good luck,
John A&P, IA