How to Summer-ize Your Truck

The brake system is often the most overlooked part of your 4x4’s systems. Brake fluid absorbs water. After a cold, wet winter be sure to have the brake fluid checked for water content and change it if it checks out bad. Wagner and Snap-on have test strips that enable you to check this at home.

Test strips or a hydrometer like this one can be used to check the percentage of coolant in your system. If the system is dirty or if the coolant has been in your rig’s radiator for 35,000 miles, drain, flush and refill it. Be sure to catch all the fluid you drain, as antifreeze is a hazardous substance and is poisonous to small animals.

New coolant won’t do you any good if you have a pressure leak in your cooling system. When changing the coolant/antifreeze be sure to pressure check both the radiator system and the cap. Repair or replace anything that is needed to get your system to hold pressure again. Remember a 15 psi cooling system will run 50 percent hotter before boiling over when compared to an open system.

When checking your cooling system don’t forget to check your hoses, too. Cracked or worn hoses may hold pressure during a test but give up the ghost on the trail.

Be sure to check your belts for cracks, glazing and abnormal wear. This serpentine belt is due for a change unless you like being stuck in the backwoods. You can carry your old belt as a spare or buy two and carry a good one along just in case.

Battery terminal corrosion can stop your truck from starting, even if the battery is in good shape. With every change of season you should check those terminals and clean any corrosion. It is also a good idea to keep the battery top clean of dirt and grime, which can conduct a slight current and result in battery drain.

Surely you’ve heard the term winterize, and you know what it means to prepare your truck for the colder months. But have you heard about summer-izing your rig? If you live in a climate that requires you to winterize your 4x4, then you’ll also need to prepare it for hard use in the high heat of the summer. It doesn’t matter if you’ve used your truck to plow snow or just let it hibernate all winter, a little pre-heat prep will save you a lot of trouble down the road. Even if you live in a place with a warm climate all year, a little preparation before you begin your summer of trail fun is highly recommended.

Just like a regular maintenance check, when you summer-ize you’re going to check the oil, and the tranny, brake, and power steering fluids. Engine oil should be changed to a heavier multi-weight to handle the heat to come. Manual trannys and differentials should be upgraded to a heavier weight lube, too. Be sure to follow the manufacturer’s recommendations here. On older 4x4s that are out of warranty, we like to run 20W-50 engine oil and 85W-140 gear oil. Automatic transmission, power steering and brake fluids only come in one weight but should be checked and changed as needed. Also, be sure to check for small leaks and fix them, as they could become gushers on the trail. Next on the list is a th0rough check of the cooling system. Everyone thinks of adding antifreeze for the winter, but this magical fluid also preserves aluminum parts and adds to your truck’s cooling capacity. A good 50/50 mixture of coolant/water will keep your 4x4 from boiling over in the summer heat. As everyone knows, pure water boils at 212 °F at sea level. By adding a 50/50 mix of water and coolant the boiling point is raised to more than 226 °F. You can quickly and easily check engine cooling system concentration with a hydrometer or with antifreeze/coolant test strips, available from Prestone and other companies. If your coolant is clean all you need to do is make sure it’s at the right mix. And yes, you do need to completely change this coolant mix periodically, since most antifreezes are good only to about 35,000 miles. After that, they begin to break down and can damage your rig’s water pump.

To further increase cooling and prevent boil-over, add a new 15 psi cap to your radiator. That will raise the boiling point further, to +265 °F. As you can see by this figure, it is very important that your cooling system be in perfect shape or your truck will be blowing its top at a mere 212 °F. Further you should check the radiator system and cap for pressure leaks. These simple tests can help you prevent damage to your vehicle’s cooling system and avoid unnecessary roadside breakdowns.

Part of your cooling system check should include a visual inspection of the system’s hoses. Cracked and worn hoses can hold pressure during testing, but may fail soon after, and at the worst possible time. Be sure to squeeze the radiator hoses, and heater hoses too, to see if you can feel any internal cracking that is not visible from the outside. Also be sure to check accessory drive belts at the same time and replace them as required.

Your truck’s charging system is almost as important as your cooling system. Here several things can be checked so you’ll know of, and avoid, any impending problems. The first step is to check the battery for any corrosion around the terminals, and to check the fluid level if you have a serviceable battery. While it seems like a waste of cash to refill you battery with distilled water, remember that the impurities in tap water can shorten the life of a battery. After cleaning your battery terminals you should load-test the battery to see if it’s getting a little weak. If you’ve just topped off the battery water, be sure to run the truck for a while to charge the battery before doing the load test. If you don’t, you’ll likely get a false indication of a weak unit. After checking your battery you should also check your alternator output just to be sure it’s up to par. If either the battery or alternator register as weak be sure to replace them before your next trip.

While under the hood you should top off your windshield-washer fluid. In the winter you’ll need to add antifreeze to the system but in the summer you’re better served to add something to help take the bugs off the glass. Bug-Z is one such additive we tried in the past. Next, replace your winter-worn wiper blades with new ones in anticipation of the spring and summer rains.

One accessory on your truck that you’re sure to have forgotten about during the winter is the air conditioning. A/C is something that you’ll never know it’s broken until you need it—unless you check it first, that is. Every season you should have a shop check and charge your A/C system to ensure cool running in the hotter months.

With all this addressed, it’s time to do some looking around under your truck. Before the trail season starts it’s a good idea to check and lube all your truck’s ball joints, U-joints, and the shift linkage for the transmission and T-case. Also check to make sure your front hubs still lock and unlock, as they could be rusted after a long winter in one position.

If you’ve parked your truck for the winter you should also check tire pressure, make sure the brakes are working, check for rusted lug nuts, and test the winch. Also consider draining the old gas from the gas tank. If you find that the gas tank is leaking due to rust caused by water condensation from the cold, you can remove it and have it renewed before the ’wheeling season. (See page 110 for more on this.) Next do a quick inspection to make sure little fuzzy critters haven’t turned your truck into a condo, wash any road salt off your 4x4, and perform a tune-up.

Finally, get your gear in order, pack your recovery gear in the back, load the camping gear, and get ready for some fun four-wheeling without the annoying breakdowns you might have faced if you hadn’t taken the time to summer-ize your truck.