Wiper FAQ - New & Used Replacement Parts

Here are some common questions and answers that may help commercial freight drivers, or drivers of any other mid size truck or even regular passenger cars.

1. Why won't my wipers clear the entire windshield? They leave bands or patches of un-wiped surface.

• Banding across the wiping area can be caused by incorrect wiper arm pressure, damage to the blade superstructure or improper blade / refill installation.  Un-wiped areas within the wiper path occur when the blade loses contact with the windshield surface.

2. Why does my heavy duty truck never seem to have wiper fluid when I need it?

• Check for leaks in the washer fluid tank and tubes. It doesn’t matter how much washer fluid you dump down the tank, if you have a leak somewhere in your system, you’ll always come up short on the blue stuff when you need it most. Check the windshield washer reservoir for cracks. If you find any, chuck it and replace it with a new one. If there aren’t any cracks in the tank, check the tubes leading to the spray nozzles for splits. If none are visible, run your fingers along the line. If you feel something wet, you found your leak. Replace as needed.

3. Why do my windshield wipers only work on a certain speed, and sometimes just quit working for a while? How do you know if it is the windshield wiper motor or the switch?

• It sounds like the switch is the problem, but you will need to check for power at the motor to be sure. Unplug the wiring harness from the motor, and use a test light to check for power when the switch is on. If you have no power, the switch or an electrical connection is bad. If the switch is on (or bypassed), give the wiper arms a moderate tug to "jump start" their motion. If a gentle tug gets them moving its likely the motor or wiper transmission.

4. What causes the haze on my windshield? The wipers won't take it off.

• Hazing is an oil-like film that spreads across the windshield as the wiper blade passes over it. Dirt or wax build-up is the most probable cause and often the rubber element has been contaminated. You should thoroughly clean the windshield and replace the rubber elements. If that fails, replace the windshield with a new or used one.

5. Why do my wipers streak and smear my windshield?

• Smearing and streaking can be caused by many things, including improper refill installation, wiper element wear or damage, or dirt build-up on the windshield.

6. What should I look for when inspecting my windshield wipers?

• There are many things to look for that will affect the operation of your wipers. Cracked Rubber - Look for splits and slashes in the rubber, evidence of a hard life. Its time to replace the element.
• Contaminated Rubber - Usually caused by road film or chemicals adhering to rubber refill surface. Clean the windshield thoroughly and replace the rubber element.
• Torn Rubber - Element has pulled away from its support, slaps.
• Improperly Installed Refill - A wiper refill that is too short or not properly installed in the blade claws loses its effectiveness immediately and may result in a scratched windshield.
• Park Set Rubber - A hardened rubber blade with little or no flexibility left, caused by direct sunlight and extreme temperature changes.
• Damaged Superstructure - Bent arm, blade or refill is a dead giveaway, caused by ice scrapers and car wash equipment.
• Abrasion-Worn Rubber - Worn down, ragged edges from rough winter conditions or infrequent rubber element refilling.

Inspect Your Medium Duty Box Truck's Brakes for Safe Winter Driving

Safe winter driving in your commercial mid-size or heavy duty truck requires good handling techniques, but even expert drivers have a hard time navigating through snow and ice in trucks that aren't prepared for wintry conditions.

Related: What Medium Duty Box Truck Drivers Should Know About Brake Problems

Every system in your truck should be in good repair to take on winter driving, but we depend on tires and brakes to roll us where we want to go and slow us down when it's necessary. Maintenance for both should be at the top of your to do list.

Knowing how to maintain the braking system properly is the key to a long lasting system and will ensure highway safety. Proper brake maintenance practices are especially vital when considering your time and more importantly - safety.

1. Addressing contamination and corrosion is important because of the ripple effect it can have on other parts of the vehicle. With all of the difference de-icing materials on the road today, inspecting the chassis components, especially the linings and wiring for damage and corrosion is very important. Also inspect for oil and water in the air brakes reservoirs. Any form of corrosion on the braking system will damage the overall system further.
2. Slack adjusters must be inspected frequently to ensure they are in optimal condition. Technicians should not adjust the brakes during preventive maintenance procedures, instead they should check the free stroke and then measure the power stroke. This will enable to technician to know if the slack adjuster is working correctly.
3. Maintain a clean air system. Drivers should drain the air tanks daily. At a minimum, the air dryer should be serviced once a year. It's imperative you keep dry, clean air in the system at all times. 
4. Perform a visual inspection or walk-a-round, adding miles or years to the life of the vehicle's braking system. Drivers are required by the department of Transportation's Commercial Vehicle Safety Alliance to perform pre and post-trip inspections. There is a good chance the driver will catch a small failure prior to a major problem. It will kepp costs under control and major repair expenses down.
5. The antilock braking system (ABS) should be in optimal order. It's essential to check the ABS warning light, the speed sensors, tone ring, wiring and connectors, and the electronic control unit diagnostics. The ABS warning light is an indication something may be wrong. During operation it may light up, which means there may be an intermittent problem the driver needs to report.

Related: Why Are My Brakes Squeaking on My Medium or Heavy Duty Commercial Truck?

The introduction of more electronic sensors will provide more information on individual components that place a higher demand on the electrical system. Undoubtedly, there will be additional data for technicians, as well as new maintenance procedures. Proper training must be in place to deal with and accept new technology.

If you or a co-worker needs replacement brakes or brake parts (booster, cable, calipers, rotor, etc.)  for your medium or heavy duty commercial truck, call us at (803) 564-3228 or (877) 564-6307. If you have any difficulties getting through our phone system, please use our Contact Form or Parts Request Form, or email sales@busbeetruckparts.com.

We have hundreds of Salvaged Medium Duty Trucks and Commercial Box Trucks for Parts including: Isuzu, Mitsubishi Fuso, UD, and GMC. With thousands of parts, including our most popular Isuzu NPR Truck Parts, we should have any part that you need in stock. Our sales professionals will be glad to assist you.  We are located at 4107 Festival Trail Rd, Wagener, SC 29164.

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