In this guide
TL;DR: A 40-foot cleaning kit describes combined rod reach. Your dryer's installation instructions set the allowed exhaust length for its vent material, hood and turns. Check those requirements before choosing rods; cleaning cannot make an overlength route acceptable.
Find the dryer chart before shopping for more reach
Start with the full dryer model number and its installation instructions. GE Appliances directs owners to the individual model instructions for duct length and clearance requirements. An existing wall connection or a tool that reaches the outside does not establish that the route suits a replacement dryer.
Record the known route, vent material, hood type and turns. Include the short transition behind the dryer as the matching instructions require. Ask a qualified installer to assess concealed or uncertain sections instead of using a brush to discover them. The duct-material guide explains why a flexible transition and permanent building duct need separate attention.
One chart shows why turns change the answer
Maytag's Electric Dryer Product Guide W11755407A, printed page 16, lists rigid metal with box/louvered or angled hoods at 64 feet with no 90-degree turns, but 27 feet with four. Its side and bottom exhaust installations add an internal 90-degree turn to the chart count. These are examples from that document, not limits to apply to every dryer.
A hypothetical 40-foot run with four counted turns would exceed that chart's 27-foot allowance even if a brush could pass through it. Use your own model's chart and complete installation requirements. Do not combine one manufacturer's straight-run allowance with another chart's elbow deductions.
Choose a cleaning kit after the installation question is settled
The current GOHALL 30-foot and 40-foot kits fit standard four-inch vents and have the same listed brush sizes. Their stated lengths are combined rods; access, bends, duct condition and obstructions affect usable reach. Neither kit certifies an exhaust installation or guarantees that the full route can be cleaned.
For a known, sound, compatible route with permitted access, follow the rod-kit procedure: turn off and unplug the dryer as its instructions require, use only the sections needed, and keep clockwise rotation during insertion and withdrawal. Stop at resistance. Leave a gas dryer in place if access could disturb its connection.
If the route exceeds the matching chart, cannot be confirmed, or needs rebuilding, discuss it with a qualified vent professional or installer before choosing a longer kit.
Vent-length question
Will removing lint increase the permitted vent length?
No. Lint removal addresses buildup. It does not change the dryer's installation chart, straighten an elbow or repair a crushed duct. Maytag's venting checks treat route length, turns and restrictions as factors that need attention.