Induced Draft Air Fin Coolers

Read an informative article on Air fin coolers on the net on basics of air cooled heat exchangers by HUDSON Products Corporation on their website.
While the comparison between induced draft AFCs and forced draft AFCs was very informative, it did not answer one important disadvantage of induced draft AFCs that we are facing in our plants.
For maintenance of top bearing and fan blades in case of induced draft AFCs, maintenance requires isolation and cooling of the AFC tube bundle before taking up preventive or breakdown maintenance. This can affect production in some units, and requires provision of isolation valves for each tube bundle. Also, unequal thermal expansion of multiple tube bundles may result in bending of tubes, leaks of valve glands, end plugs etc.

How do other users of induced draft AFCs handle this issue. Is there no other way but to isolate the tube bundle for maintenance of the rotating parts?

Any comments or suggestions?