Summer Weather Maintenance Tips

Caring for, and maintaining vehicles, during the summer months is just as important as in the winter. Like cold weather conditions, summer’s hot and dry weather causes additional stresses on vehicles as well.

Making the time now to summarize vehicles will help them take the heat and keep operating efficiently.

A good starting point is the truck’s engine cooling system, which is designed to protect an engine from the destructive forces of too much heat and keep it operating at its most efficient temperature. In hot weather, the coolant temperature is raised. As a result, the cooling system has to work harder to keep the engine from overheating.


Research has shown that an estimated 40 percent of engine downtime is caused by cooling system problems. Yet, cooling system problems are virtually 100 percent preventable.

Even one cooling system overheat can severely damage a truck engine, observes Sandy Darnell, president of Radiator Works. Therefore, it is well worth the time and effort to regularly perform certain maintenance checks and replace the low-cost wear parts to maintain a properly functioning engine cooling system.

Radiator Works is a full-service manufacturer and distributor of heat transfer components and parts and services for lift trucks, buses and commercial trucks.

She recommends the following preventive practices:

  • Inspect the inside of the radiator for corrosion, and check to be sure the coolant is clean and pure, with no rust or other impurities. Coolant should be drained and flushed annually - at a minimum.
  • Inspect the radiator cap for cracks and/or swelling, and replace it every time the coolant is drained and flushed.
  • Perform a cooling system pressure test. This, too, should be done, at a minimum, on an annual basis.
  • Inspect the exterior of the radiator and the air conditioner cooling coils for excessive debris buildup or fin damage, and clean as necessary.
  • Inspect all radiator and heater core hoses and lines for excessive mushiness and hardness, and check for cracks and leaks. Be sure all the connections are tight. Replace hoses every two years.
  • Inspect belts for wear and tension, and test the function of the tensioner arm. Replace the belts every one to two years.
  • Replace the thermostat every two years.
  • Inspect the water pump for leaks, and verify that the engine maintains a temperature within the manufacturer’s specification.
  • Run the truck heater to verify that the system functions properly.


Obviously, good cooling system preventive maintenance practices include the coolant itself, which, officials at Penray recommend, should be checked every 500 operating hours, 20,000 miles or three months, whichever comes first.

Penray is the leader in cooling system technology.

Further, they say it is important to “know your coolant” because of the many different colors and chemistries available.

Coolant comes in all different colors, note the officials, and the color indicates the kind of coolant and how it is to be maintained. Mixing of technologies and not maintaining them correctly can lead to cooling system problems.

Regardless of the color, all coolants should have one thing in common, they say. All should be clear. Coolant that appears cloudy or has particulates floating could be an indication of bigger problems.

The Penray officials stress the need to maintain and monitor coolant chemical levels. Depending on the type of coolant in an engine, there are different maintenance practices that need to be adhered to, including the engine manufacturer’s drain intervals for the coolant type.


Hotter weather conditions necessitate that greater attention be paid to tire inflation pressure.

The most critical factor in tire maintenance is proper inflation, according to tire industry officials.

With correct tire inflation, there is the proper contact with the road surface, they say. That promotes traction and braking capability, plus reduces irregular and rapid tread wear. All of this helps with safer vehicle operation.

Improper inflation, conversely, can have detrimental effects on the performance of both tires and vehicles. It also results in irreversible damage.

Underinflation causes abnormal tire deflection, which builds up heat and causes irregular wear. Overinflation causes tires to run hard, which increases road shocks and vibrations transmitted to the vehicle, and also causes irregular wear.


Because of summertime’s higher temperatures, the air pressure in a warm tire rises. Since air is a gas, it expands when it heats up and contracts when cooled.

Tire officials advise against bleeding air from a hot tire to relieve normal pressure buildup. Bleeding air pressure will result in underinflation because as the tire cools at the end of the shift or day, inflation pressure will drop.

The normal increase in pressure due to service conditions will be 10 to 15 psi, and this is allowable in a radial truck tire, they point out.

Checking and adjusting tire inflation pressure should always be done when tires are “cold,” say tire industry officials. That is, after a vehicle has been parked about three hours, before it’s been driven any more than a mile or before rising ambient temperatures or the sun’s radiant heat affects the pressure.

The officials recommend that tire inflation pressures be checked on a regular basis - at least once a week. This check should always be made with a calibrated tire gauge or a gauge that is checked periodically with a tire gauge known to be accurate.

Furthermore, they suggest the use of valve caps to help keep air inside the tires. If left uncovered, water and dirt can get down into the tire value stem can cause it to partially open, allowing air to escape.

Sealing metal or nylon valve caps, or quality “air-through” type caps, are the best, they point out.


One other key area to focus on when prepping vehicles for summer is the electrical systems, say officials with Kenworth Truck Company’s PremierCare Parts & Service group.

They suggest taking the following measures:

  • Check the alternator’s wiring to make sure the electrical wires haven’t come loose and moved within contact of fuel lines or any abrasive items.
  • Inspect the vehicle’s batteries to ensure that they are firmly mounted in place.
  • Check the integrity of the battery cables where they connect to the battery, and make sure the fasteners are secure.
  • Look for corrosion at the battery’s terminal posts. If corrosion is present, clean it off and spray the connections with a battery protectant.
  • Inspect the battery cables to assure they aren’t in contact with items that will wear through their insulation.
  • Check the wiring to and from the engine’s electronic control unit to make sure it is in good condition.