CHEVROLET 2009 Suburban - Manual (Page 421)

3. Remove the engine air cleaner/filter from the
housing. Care should be taken to dislodge as
little dirt as possible.
4. Clean the engine air cleaner/filter sealing surfaces
and the housing.
5. Inspect or replace the engine air cleaner/filter.
6. Reinstall the cover and tighten the screws.
{ CAUTION:
Operating the engine with the air cleaner/filter off
can cause you or others to be burned. The air
cleaner not only cleans the air; it helps to stop
flames if the engine backfires. If it is not there and
the engine backfires, you could be burned. Do not
drive with it off, and be careful working on the
engine with the air cleaner/filter off.
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