Locate and turn off the water to the swamp cooler. Often there is a "T" saddle valve that shuts off the water.
Disconnect the ¼-inch waterline from the faucet or waterline so that the water will drain from the line. Any water left in the line will likely freeze and break the line if it is not drained. It may be necessary to blow air thru the line to remove all the water. Use an adjustable crescent wrench to loosen the copper fittings. Use care not to damage the fittings.
Go to your swamp cooler, but first make sure it is turned off. If your swamp cooler is a roof mount or window mount, a ladder may be necessary. See Warnings below and take precautions for using a ladder safely. Use a formula to angle your ladder using one unit for every 4 units tall.
Open the cooler by removing one of the cooler pads. Be sure that the cooler fan and water pump are turned off. For added safety and when equipped, unplug the fan and water pump plugs located inside the cooler.
Remove each of the cooler pads from the swamp cooler and inspect them for damage and to determine if they need replacing. Normally the wood fiber filter pads last from one to two years before they need to be changed. Ways to determine whether to change them are when they look exceptionally gray colored, contain lots of hard water, missing large areas or smell bad. Purchasing pads at end of season prices can save money when available otherwise replace them in the spring time. Inspect the top of the pad where the water enters for hard water deposits and rust. Scrape and remove this as needed to remove all obstructions.
Prior to draining the water from your cooler, connect a second garden hose to the bottom of the drain to prevent the water from the cooler from making a white hard water stain on your roof. Remove the drain plug in the bottom of the swamp cooler and let the water drain completely out of the swamp cooler. The drain is usually a pipe that can be pulled or twisted out to drain the water.
Attach a garden hose and sprayer to clean and wash out the bottom of the swamp cooler and the cooler pads. This removes dirt and hard water deposits. Remove the water pump and clean the screen to remove dirt and hard water. Set the drain and overflow plug aside and do not install it so that any water that might accumulate during storage will drain from the cooler. This is an important step. This water hastens rusting, smells and makes an easy place for mold to accumulate.
Check the fan belt for wear and tension. Replace or tighten as needed. Use the illustration below for a guide to tightening the belt to less than 3/4 of an inch tension.
Check the motor mounts to make sure they have not loosened during the season.
Check the frame work supports for loose bolts and tighten as needed. Look for frayed or loose electrical wiring and take steps to turn off the power and repair or replace any worn or damaged wiring. Make sure that none of the wiring comes in contact with the water in the swamp cooler. Secure any loose wire and connections.
Oil the squirrel cage and motor bearings. Use a light oil specific for use in swamp coolers. This will help to prevent rust forming in the bearings both now during the storage period and next season's usage.
Unplug the fan and water pump so they cannot be accidentally or needlessly turned on during storage.
Correct loose bolts and motor mounts. Tighten electrical fittings.
Use a swamp cooler paint or marine paint to stop rust. Remove rust prior to painting. Check the base of the swamp cooler for leaks and cracks where it connects to the roof and patch with tar as needed to prevent leaks.
Shake off water and reassemble the parts removed for cleaning. Make sure to leave the drain plug off so that any accumulating water will drain during storage.
Use a tarp, heavy plastic or fitted cover to protect your swamp cooler during the off season. Use a rope as necessary to securely hold the cover in place during severe seasonal wind storms and prevent loose portions of the cover from flapping.
A cover slows down the loss of heat from your home and reduces the noise from wind and traffic that often funnels back into the house through the cooler ductwork. A pillow and/or cover should also be placed in the ceiling vent further reducing the loss of heat and reducing noise.