This is one of the easiest jobs on a T1 Silverado, and it needs almost no tools — a 7 mm driver or a No. 2 Phillips for the glove box fasteners, a plastic trim tool, and a flashlight. The filter lives in the HVAC case behind the glove box and slides out into the passenger footwell through a small snap-on door. Engine choice makes no difference: 2.7 Turbo, 5.3 L84, 6.2 L87 and 3.0 Duramax trucks are all identical here, as are single- and dual-zone climate systems.
The thing people get wrong is assuming the slot already has a filter. A lot of T1 trucks, especially earlier builds and base WT/Custom trim, left the plant with an empty housing, so owners pull the door off, see nothing, and assume they are looking in the wrong spot. The other common miss is direction: get the airflow arrow pointing the wrong way and you will lose vent volume and may get a blower whistle.
| Item | Type | |
|---|---|---|
| Flashlight or headlamp LED, hands-free preferred The filter door is deep in the footwell shadow behind the glove box. | Required | shop |
| Plastic trim tool set Nylon pry/wedge set Releases the glove box side clips and the lower right dash trim without scratching or cracking it. | Required | shop |
| No. 2 Phillips screwdriver Stubby and standard length Removes the glove box and lower dash panel screws, which are Phillips-head on most trims. | Required | shop |
| Socket driver / ratchet 7 mm socket, 1/4 in drive with short extension Some T1 trucks use 7 mm hex-head trim screws instead of plain Phillips on the glove box and knee bolster. | Required | shop |
| Shop vacuum with crevice tool Sucks out leaves and debris from the filter housing before the new filter goes in. | Recommended | shop |
| Nitrile gloves Used filters carry mold, dust and rodent debris. | Safety | shop |
| Dust mask N95 Avoid breathing the dust that falls out of a loaded filter. | Safety | shop |
| Cabin air filter T1 Silverado 1500 single flat filter — ACDelco CF199-type; confirm by part lookup for your VIN The replacement element itself; carbon/charcoal versions fit the same slot. | Parts | shop |
| HVAC evaporator cleaner Aerosol foam or spray, odor-eliminating Optional: spray into the empty filter slot to kill musty A/C smell while the housing is open. | Consumables | shop |
| Blanket or fender pad Makes lying across the passenger footwell tolerable. | Recommended | shop |
No differences by engine. The 2.7 Turbo, 5.3 L84, 6.2 L87 and 3.0 Duramax all use the same behind-the-glove-box filter and the same fasteners; only screw type (Phillips vs 7 mm hex-head) and count vary slightly by trim and model year.
| Glove box / lower dash trim screws | Snug by hand only, approx. 1.5-2 Nm — verify in the service manual |
Location (behind the glove box, footwell-facing door on the HVAC case) is solid for the whole 2019-2024 T1 generation and identical across 2.7 Turbo, 5.3, 6.2 and 3.0 Duramax; the exact screw count and whether they are Phillips or 7 mm hex varies by trim year, so check what your truck has before buying, and confirm the filter part number against your VIN.
Behind the passenger-side glove box, in a footwell-facing door on the HVAC case low and to the left of the glove box opening. You have to drop the glove box to reach it; there is no exterior or under-hood access.
Many T1 Silverados and Sierras were built without a cabin air filter installed, particularly earlier 2019-2021 trucks and base trims. The housing and access door are still there, so you can simply install a filter yourself.
The airflow arrow must point in the direction air travels through the case — rearward/downward into the blower on the T1. Note the orientation of the old filter before you pull it out, or check the arrow molded on the housing.
Roughly every 15,000 to 22,500 miles, or once a year. Cut that in half if you drive dirt roads, tow in dusty conditions, or notice musty smells or weak vent airflow.