National Service Manager – Prochem
With flashlight in hand and covers removed, look behind the control panel, this is the electrical center for the unit and it should be neat and all wires bundled and away from any moving parts. If you see wires that are cut or spliced with a different color wire, beware, the operator may have bypassed a problem or safety switch so be sure to ask for an explanation.
Moving toward the back of the unit, look for oil leaks, especially around the base of the engine as it is hard to clean leaking oil from around the engine base. If the unit is water cooled look for signs of anti-freeze leaking and check out all coolant hoses. Most engine water pumps and coolant hoses will be located near the front of the unit. One thing I always look at is the hose clamps, if the clamps are the wrong size or the end of the clamp is too long, this is a red flag for me, a good mechanic will take the time to use the correct clamp. Inspect all belts, blower, water pump and any other components driven by a belt. When inspecting the belts don’t just look at the top, turn the belt so you can see the bottom of the belt and look for cracking or pieces missing from the belt, bad belts are a red flag. Check all fluid levels and pay attention to the color of the oil, most oils will have a light color. When checking the engine oil, slide the dip stick between your thumb and finger, now rub the oil between your thumb and finger, the oil should be smooth without feeling any particles or grit.
Check the engine air cleaner, just like an automotive air filter, hold it up to the sun light or flashlight and you should be able to see light coming through the outside of the air cleaner. If the air cleaner is plugged the engine will not run properly. Finally check the waste tank to see if it is clean and without critters growing in it, it may have some signs of use but it should be clean. Also look at the truckmount frame for rust, surface rust will be fine as you can wire brush and repaint.
If everything is looking good then ask for maintenance records on the unit, this should include general maintenance as well as any major repairs that have been done to this truckmount. Since you have looked at the owner’s manual you will know how often the fluids need to be changed, prolonged oil changes can cause internal damage that is not visible. Ask the owner who takes care of the maintenance on the unit, if it is taken care of by the operator inquire about his mechanical experience. You don’t need to make it an interrogation, you are just making sure you are going to get what you pay for. If the truckmount is serviced by the local authorized dealer, authorized being the key word, then they will have the documentation to back up what the owner is telling you.
If so far so good, throw a piece of carpet on the ground and take it for a test drive. Don’t be in a hurry; this should take at least 30 minutes to fully test the unit. Watch the owner start the unit, most truckmounts have a bypass switch. The bypass switch will bypass safety switches (oil pressure) while the unit starts, once the engine starts the bypass should be release and the unit will continue to run. The exception to this is Electronic Fuel Injection (EFI) does not need a bypass switch to start. While the unit is running listen to how it sounds. Even if you are not mechanical you can tell when something is wrong. Watch the gauges, they should be working and the water pressure and vacuum gauge should be full of glycerin. Once the unit has come up to temperature start cleaning the carpet and watch how it holds the heat and vacuum. If the unit is equipped with a chemical system this would be a good time to test it. If after you have cleaned with the unit and it has passed your tests you have found a good used unit. Now make sure you have cash in hand, good truckmounts don’t stay for sale very long.