The air filter was the Achilles' heel of early T-34 tanks. The early Pomon air filters were inefficient and had to be cleaned often, which was not always possible in the heat of battle. These filters were later replaced in production with Cyclone and later Multicyclone filters. These filters proved themselves to be superior, as reports from the 2nd Guards Tank Army during the Berlin Offensive Operation indicate.
"It is worth remarking that the Multicyclone air filter proved themselves very reliable, despite heavy dust that the tanks and SPGs had to work in both during the march and during the span of the whole operation. Not a single engine went out of action because of the air cleaner, even though the roads were very dusty. If the Multicyclone air filter is properly maintained and installed, this type of air filter should be considered optimal for tank engines."
The filters performed well, even though the proper maintenance mentioned in the report was not performed.
"It is worth mentioning that full service procedures for tanks and SPGs were not followed. For instance, in some units air filters were not cleaned for as long as 15-20 hours of running."