Buying a Used Jeep: Post-Purchase Preparation

Jan. 19, 2015 By Jim Brightly, KF7SCT
I love the look of an orange Jeep on fresh snow. In the desert, a brightly colored vehicle—whether it’s winter or summer or in between—can save your life if you become stuck while out alone.

Over the decades I’ve been four-wheeling, I’ve purchased several new Jeeps but I’ve bought many more used Jeeps than new during the same timeframe. When you buy a new rig all you have to do for the first several thousand miles is fill the fuel tank. Not so with a used rig.

Since I’ve never seen a Jeep break down in the driveway, I always go through the Jeep and change out anything I can. That way, when I hit the trails, I’m starting at near to zero as possible with a used Jeep. That means changing out all the fluids: engine oil, coolant, differential (gear) oil, and transmission and transfer case fluids. I check the brake fluid but if it looks clear, clean, and moisture free, I leave it alone. I do check the brakes for wear, if the pads need changing and/or discs need resurfacing, I’ll do that plus change out the fluid.

Change the engine oil, gear lube in the differentials and transmission (if a manual), and ATF, and if you feel energetic, change the fluid in the transfer case, too. Make sure you have a shop manual so you know what viscosity lube to use in each device.

Don’t forget to change the oil filter when you change the oil and lube the chassis.

Next are the windshield wipers. When you buy a used car you have no idea how long its windshield wipers have been riding out there in the sun and weather, so you might get a nasty surprise in the next rainstorm. Replace them and don’t stint on the price here: as a rule of thumb; the better the wiper, the better it’ll wipe.

Although this is a really convenient place to carry the spare fan belt, it would be better—and last longer—sealed in a Zip-lock baggy in your to-go bag.

On the LJ, the radiator drain valve was on the passenger side and was just finger tight. Twist it counterclockwise to open it. Make sure you drain the coolant mix into a bucket or where pets won’t have access to it. Dogs, especially, like its sweet taste and it could harm them.

While draining the cooling system, release the radiator cap and the cap on the puke tank. This will help the system drain faster.

And, finally, the fan belt; replace it and save the old one. Inspect it very carefully before saving it; however, to make sure it’s worth saving. If it’s glazed, cracked or fraying, throw it away and buy another fan belt and store it in the Jeep. A broken or slipping fan belt can sideline your Jeep very quickly. I’ve been saving fan belts for decades and have had to use one once… on a friend’s Jeep. But it still beats sending a friend for one or trying to use panty hose.

If you don’t have a pair of cable pliers, pick one up before starting to remove the factory spring clamps from the hoses. They’re much safer and quicker to use.

Be careful not to break the heat sensor just to the right of the heater hose in this photo. If you break it—as I did—it’ll trigger your “check engine” light.

Reinstall the new hoses in the reverse order of removing them. Here, you’ll want to remove the upper hose first and the lower hose second.

These are the four molded and shaped hoses needed to change out on an LJ. Some hoses are different diameters at the ends, so buy molded hoses not generic ones.

I’ve found that a small spray of silicone can aid in sliding the new hoses into place.

Use a ratchet and socket to tighten the new hose clamps rather than a screwdriver. They’ll be more secure.

Lastly, inspect the entire Jeep for weak spots, such as a rusted out bumper, damaged or weak control arms, dented driveshafts, etc. On the Rubicon Unlimited in the photos, I found that the rear bumper had too much rust for me to feel comfortable towing a trailer with it, or even trusting it to hold while snatching another Jeep off a rock or out of a mud bog. I replaced it as soon as I could.

The new Bestop bumper that replaced the older, rusted out steel bumper can be trusted to tow or tug. Newsletter
Join our Weekly Newsletter to get the latest off-road news, reviews, events, and alerts!