Howdy Looking to buy my first excavator. My use is that I have some property out in the woods that I want to build some roads on and only will be using the machine on weekends probably between 50 to 200 hours a year. For this reason I am looking at older used machine's and even considering a gray market machine. (down time is not a worry) I have done several searches on buying used equipment on this form and this is the checklist that I put together. I thought I would put my checklist up for review to see if any of you would add to the list. To be honest, I do not know exactly what all the items are on the checklist and if I listed the same thing twice under different names now you know why. My inspection qualifications are. I took auto shop in school thinking I might become a mechanic. I have done mechanical work on my cars and my friends cars and I have worked in construction around heavy equipment for 30 years and have done minor maintenance and repairs on equipment. Thanks for your time Pre-purchase checklist for excavator #1 Run it for a couple of hours Undercarriage the pins the rollers the track swing bearing the gear oil in the final drive swing motor Hydraulic fluid level hydraulic fluid for moisture motor oil level engine for moisture engine coolant level excessive smoke from engine I assume the only way test the hydraulic pump is to simply run the machine and see how quickly the hydraulic rams respond or listen for odd noise. Are there any other fluid levels that need to be checked ? Hydraulic Hose conditions Hydraulic ram seals grease fittings in good shape Joints were properly greased Hour meter (although I don't know how much I would trust one an a 30 year old machine) Do the gauges work Battery condition Is the electrical system charging electrical system and wiring check for: a. for shorts b. for overheating/melted wires c. proper fuses d. frayed wires e. bad repairs Rust Availability of filters availability of parts accessibility to work on the machine terms that I found and do not know what they are: Hy Dash type. The planetary gear the sun gear slew ring bearing RV / Camshaft / Engaging Pin system final drives Information I gathered from Forums Check the machine out. Does it fire right off, or does it have to run the battery down from cranking so much to start it. Does it smoke excessively. Very important, pin and bushing connections of joints. Leaks. Pump noises. Condition/color of hyd oil. Tightness of slew ring bearing. Wiring, has it been butchered by some jack wagon with a pocket knife and electrical tape. Condition of cab interior and seat. Does all the switches/functions inside cab work. Hoping someone can help. I'm looking at a used JD 50D with under 400 hours. I have a little concern with how much play should be in the boom swing joint. This has about an 1/8" or so. Everything else seems pretty tight. The only other thing is some play in the front pin in the bucket coupler. Not so much play in the pin bore, but side to side play. Not sure if there should be any shims in there or not. Most of the other joint have what looks to be stainless shims in them. Slew ring wear is detected by lifting the boom off the ground and then moving the body with your hand, noting where the play is, with swivel boom machines there is usually a little in the swivel mechanism. Best off to use two people to check that, one to move the body and another to look how much slop is in the slew ring. If there is any up down wear in the turntable you measure that by placing a dial gauge between the undercarriage and body and then using the boom to push the body up. It is very dangerous but I stand beside the machine and operate the handle closest to the entry area to drop the boom or dipper to the ground then watch as it pressures down to the ground to lift the body (house) off the H-frame (track frame). If the tracks lift instantly off the ground then the bearing is probably good for up and down play. If there is any movement of the house,(upper body) before the tracks move up then you have to bend down and watch the turntable bearing to see if that is where a gap opens up between the top and bottom of the bearing. I am usually inspecting machines by myself so this is my method, it is much easier to check it with another person watching the bearing while you operate the boom. Any vertical play is not good, if it is 1/16" I would note it but not condem the bearing. However the hardened surfaces of the bearing could be gone and it could start to get worse quickly. This is only for vertical wear. Look for grease to be pouring out of the bearing (bad seal). also on larger excavators, I have seen lots of oil pouring out of the swing bearing because the swing motor seal blew out. The side to side play in the gear teeth could be excessive, however I don't think know that there is a definate rule of thumb, if it has a lot of side to side play it will make the excavator harder to zero in on the bucket target as it rocks to a stop. I also like to check the swing brake at this time. When I operate the swing, it should smoothly and quietly come to a stop when you center the swing control. Any noises or chattering or no stopping are usually expensive swing brake or hydraulic motor repairs. Look under the center of the machine for leaks from the swing motor seal or as mentioned before oil leaking from the turning table bearing could be from a bad swing motor seal. Anything over 0.070 up and down is worn out. Swing brakes do not stop the house from turning. They only hold the house in place after the controls are all released for about 7 seconds or so. Swing motor pinion leaks show up on the swing bearing and drip down on the carbody. It is usually very obvious. There is nothing you can do about free play between the ring gear and swing pinion gear short of changing both. Take a 12mm allan key with you and check the colour/level/smell of the oil on the final drive planetaries on the tracks. Check slew gearbox oil as well....all fluids infact. On any excavator you should check all compartments for signs of leaks, weeping hoses/connections. Lay the arms down and have a good look for damage on all the hydraulic cylinder rods. Evidence that it has been greased recently is also a positive. I think you need to consider the history as much, if not more than the hours. If it has had a genuine owner or two .....don't consider excessive hours If it was ex rental it was probably due to go for scrap at 3yrs old The general state of the machine should give a clue to what life its had. Why is it for sale? Has it had a 2 gallon respray walk away Check undercarriage for excessive wear, replacement. On rubber or steel ? Pull the dipstick Put the bucket just off ground and push it and dipper about with your hand for clue as to wear on pins etc. Check for leaks, drips, cab/canopy scraches, dents, repairs. Does the hour clock actually work Look it over from a critical point of view, and take some pictures . . How do you check a turntable for wear? Lift bucket off ground a few inches, then get out or have someone push bucket from side to side and observe total rotational movement. A few inches is OK, Much more than a foot or so is too much, taking in consideration some slop in bucket pins and boom. You can also use the swing control to turn back and forth and both observe the rotation and feel the slack in the gears. Have someone use the boom to move the house up and down and watch the movement in the swing bearing. Some manufacturers have a spec for this. There should not be much movement up and down in the bearing. I've seen some that were really worn, but they still worked fine. Kepp the bucket off the ground again. Move it up and down and side to side. A little movement side to side is okay. You do NOT want too much movement up and down. Just set the boom and bucket at a normal attitude, stick straight up and down, bucket on ground. Either you or someone else has to observe, and the other person just has to move the machine up and down a bit, just enough to take any slack out of the rotek. Rotate the machine and do this every 90 degrees. So far as checking the swing; boom and stick in same position as above, with bucket off the ground a couple of feet or so. Do not engage the swing lock or hydraulic disconnect. You can do this one by yourself. Get out and go out to the bucket and push it back and forth sideways. It will spring back a bit, be careful.
If its been repainted I wouldn't rule it out. The machine could have been owned by someone like me, who has more money than common sense. :tong I painted my dozer, just to make it purdy and neat looking. But anyways, my ex120 had been repainted before me, and after a year and a couple hundred hours later, the only major problem (Not even major really) was having the swing motor rebuilt. I've changed two hoses, and fixed a broken vent too, but other than that, she's served me well.
You know, it's all very well checking all this stuff while your blue in the face but in my opinion, your best bet is to find one that is privately owned, you should be told by the owner it's good and bad points. Just my 2c.