I'm trying to replace the bearings in my Century B2982 motor, but I cannot separate the motor flange from the pump housing's seal plate. The pump is an old Purex Triton UltraFlow (I think the current part is AMERICAN 357143 SEAL PLATE VAL-PAK FOR ULTRA-FLOW PUMP V38-131).

There are four bolts that secure the motor flange to the seal plate, and I have removed those. I have tried a variety of things, including hitting the seal plate, hitting the bolts, etc.

It appears that the calcium buildup may be bonding the two parts. Is there a trick of the trade that would help separating these parts?