Dust, sand, and small pebbles can scratch the window as they rub against it. It’s usually best to avoid using petroleum-based solutions, like WD-40, on wiper blades. If you use products like this frequently, they can dissolve the rubber and shorten the life of your blades.

The output of the gear reduction operates a linkage that moves the wipers back and forth. The circuit maintains power to the wipers until they are parked at the bottom of the windshield, then cuts the power to the motor. This circuit also parks the wipers between wipes when they are on their intermittent setting.

Clean your wiper blades by wiping them down with warm, soapy water, and wipe the edge of the blade with rubbing alcohol. If you’re still having issues with smearing water, try upgrading your wiper fluid.

WD-40 can be used on just about everything. It is safe for metal, rubber, wood and plastic. WD-40 can be applied to painted metal surfaces without harming the paint.

1. Spray the rubber with silicone spray.
2. Keep the rubber in the plastic bag for three to seven days.
3. Lift the bagged piece of rubber and bend it to check for pliability.
4. Heat some water in a stew pot on the stove.
5. Set the stew pot in the sink and submerge the rubber in the water to soften it.

Sulfur. Sulfur was the first curing agent used to soften natural rubber and it is still used today.

The higher the temperature, the faster the rate of deterioration. Cooler conditions, therefore, promote longevity. Avoid hot lights, proximity to any heat source, or any storage or display practice that heats objects. Ideally, rubber and plastic objects should be stored in cold, dark, dry, and oxygen-free conditions.

Wherever you find rubber, don’t clean it with vinegar. The acid can eat away at rubber just as it does natural stone, causing it to degrade. Instead, use soap and water or a solution of soap and baking soda.

But in other aipects of automotive manufacture and maintenance, glycerine finds wide fields of application. In the latter the glycerine acts to keep the rubber from “drying out.” Not only the cleaning but the processing of rubber used in tires may use glycerine in th’e vulcanizing medium.

The glycerin mainly preserves rubber and prevents it from drying out, but can also rejuvenate and restore rubber, albeit to a limited extent. Using wool dryer balls to soften your clothes. Pull the rubber out of the boiling water, then dip the cotton wad into some glycerine, and wipe down the rubber item with it.

It does soften up old seals. I use it on all my cars about 1X per year. I have never seen another product quite like it. Downside: Like Brad said, it does leave residue and can cause problems if you don`t wipe it down thoroughly after application.