Looking at used tractors

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arkie 74

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I am looking to buy a used tractor within the next 2 months. I know you can do a compression or leak by test on gas or smaller engines. Can you do this on 75 to 100 hp tractors. Also, would you have the hydraulic pressure tested? Any other suggestions would be appreciated.

Thanks
 
In order to do a compression on a diesel you need to take the injectors out instead of the spark plugs on a gas engine, will also need a higher psi gauge.
If it was me I would see if I could get the tractor to the farm during the busy season and use it for a while.
 
Testing the hydraulics might be as simple as putting a load on the lift arms and/or the front-end loader and see if they hold over a period of time.
 
you can pull an oil sample and have an analysis done on it which will tell you quite a bit about the engine

run the tractor and see if there is any blowby coming out of the engine and on a diesel engine if they have low compression they are usually hard to start
 
Angus Cowman":2jgocsh1 said:
you can pull an oil sample and have an analysis done on it which will tell you quite a bit about the engine

run the tractor and see if there is any blowby coming out of the engine and on a diesel engine if they have low compression they are usually hard to start

You can do the same on the hydraulic oil, the results will tell you what type of metal is in there so you know what is wearing. You can put a pressure gauge in the remotes or better yet a flow meter to really test the pump.
 
Compression tests are difficult to do on a diesel, and most dealerships don't bother. You may be able to convince them to dyno it. Only takes an hour or so.

Having said that, if it starts good (for that type of engine), and doesn't push alot of smoke out the breather when its warm, then you're probably just fine.

But DEFINITELY pressure and flow rate the hydraulics. Tests are easy to accomplish and will tell you much about the tractor. Also take a flexible mechanics magnet with you. If the filler (both lube and hydraulic) are directly into the pan or transmission, take your little magnet and fish around a bit.

Rod
 
DiamondSCattleCo":3413cq5n said:
Compression tests are difficult to do on a diesel, and most dealerships don't bother. You may be able to convince them to dyno it. Only takes an hour or so.

Having said that, if it starts good (for that type of engine), and doesn't push alot of smoke out the breather when its warm, then you're probably just fine.

But DEFINITELY pressure and flow rate the hydraulics. Tests are easy to accomplish and will tell you much about the tractor. Also take a flexible mechanics magnet with you. If the filler (both lube and hydraulic) are directly into the pan or transmission, take your little magnet and fish around a bit.

Rod
Dyno won't tell you much about the condition of the engine. Even a low compression diesel can push out good HP. The oil tests would be a good idea as would testing the hydraulic pressure and flow. I would warm the hydraulic oil up good and see how she does. I know many tractors I've looked at seemed decent when the oil was cold but when she got warmed up the oil thinned and a poor pump was easier to spot. I would also look at the hydraulic oil filter. I've seen tractors that seem good and decided to pull the filter to be sure there were no problems there. Filter came out full of filings. The list goes on and on.
 
novaman":3kjc3hn5 said:
DiamondSCattleCo":3kjc3hn5 said:
Compression tests are difficult to do on a diesel, and most dealerships don't bother. You may be able to convince them to dyno it. Only takes an hour or so.

Having said that, if it starts good (for that type of engine), and doesn't push alot of smoke out the breather when its warm, then you're probably just fine.

But DEFINITELY pressure and flow rate the hydraulics. Tests are easy to accomplish and will tell you much about the tractor. Also take a flexible mechanics magnet with you. If the filler (both lube and hydraulic) are directly into the pan or transmission, take your little magnet and fish around a bit.

Rod
Dyno won't tell you much about the condition of the engine. Even a low compression diesel can push out good HP. The oil tests would be a good idea as would testing the hydraulic pressure and flow. I would warm the hydraulic oil up good and see how she does. I know many tractors I've looked at seemed decent when the oil was cold but when she got warmed up the oil thinned and a poor pump was easier to spot. I would also look at the hydraulic oil filter. I've seen tractors that seem good and decided to pull the filter to be sure there were no problems there. Filter came out full of filings. The list goes on and on.

Dyno will tell you how the engine pulls under load and you get to load the pto up to make sure it does not slip. To me a dyno run, hyd flow test and a oil analysis is about all you can do besides a good visual inspection and test drive. Some dealers will bring a used tractor out and let you use it.
 
novaman":22r6jcs5 said:
Dyno won't tell you much about the condition of the engine. Even a low compression diesel can push out good HP.

Your statement is completely dead nuts wrong. Dynos have been used by heavy engine techs for decades to determine _if_ and _what_ issues a powertrain may have.

Every manufacturer publishes HP specs, along with a tolerance guideline as to acceptable leeway. You put the unit on the dyno and watch it run for an hour with a gradual application of the resistance mechanism. Then you watch how the unit responds. Amount of smoke, color of smoke, engine noise, oil pressure, excessive heat from the PTO, and OVERALL HP will give you an accurate assesment of what kind of shape the power unit is in. It will point out oil consumption, blowby (two different things, one caused by bad wipers, the other by bad compression rings), injection pump weaknesses and bearing weaknesses.

Oil analyses are an internet fallacy, especially the $18.95 "we analyze it all" types you see listed. Often times the companies don't bother to clean or sterilize testing equipment properly, with the end result being completely inaccurate.

For an oil analysis to be remotely accurate the following conditions MUST be satisfied:
1) Your engine oil must have a baseline analysis.
2) You must know the hours on the oil that you've sent away.
3) The power unit must have a history of accurate analyses.
4) The analysis must be done by a reputable lab. This style of analysis will typically cost a couple hundred bucks.

Even if the power unit has a history of analyses, chances are the oil will have been changed anyway, and no dealer (or privateer) will let you put 2 or 300 hours on an engine, then wait 2 weeks for an analysis to come back.

Quite frankly your best tool is somone who knows engines and tractors, especially if they're familiar with the unit you have your eye on. A good wrench can hear and spot potential issues without having fancy HP tests and oil analyses...

Rod
 
Thanks to everyone who has responded. Sorry it took so long to respond to the post. I looked at the tractor Friday and drove it around there lot for about 1 hr. I will tell you a little bit about the tractor. It is a JD 2007 6430 with around a thousand hrs has original warranty till 7/09 and they sent off oil samples which was certified by powergard for extra warranty and they have added 1yr or 2000 more hrs to the warranty through powergard. They are looking in to me adding alittle more warranty to it. After reading the post I will have them do a dyno if we can settle on price. I wish i could use it for a couple of days but I am about 150 miles from where the tractor is located. That is the bad thing about looking for used tractors. Should The dealer let me watch the dyno or should i be ther for the test? Also should I draw my own oil sample and send them off or just take there word for it? Since its be certified through powergard. I know a mechanic from a local dealer and thought about asking him to go with me durning the dyno.

Thanks to everyone
 
With warranty and a lousy thousand hours on the tractor, I'd take your mechanic friend back with you to listen to it. I'd be shocked if there was a single thing wrong with the unit. I wouldn't worry about the dyno. But try for it anyway and if they balk, tell them to knock a couple hundred more dollars off. :)

Rod
 
DiamondSCattleCo":ysergqlw said:
Oil analyses are an internet fallacy, especially the $18.95 "we analyze it all" types you see listed. Often times the companies don't bother to clean or sterilize testing equipment properly, with the end result being completely inaccurate.

For an oil analysis to be remotely accurate the following conditions MUST be satisfied:
1) Your engine oil must have a baseline analysis.
2) You must know the hours on the oil that you've sent away.
3) The power unit must have a history of accurate analyses.
4) The analysis must be done by a reputable lab. This style of analysis will typically cost a couple hundred bucks.

Even if the power unit has a history of analyses, chances are the oil will have been changed anyway, and no dealer (or privateer) will let you put 2 or 300 hours on an engine, then wait 2 weeks for an analysis to come back.

Quite frankly your best tool is somone who knows engines and tractors, especially if they're familiar with the unit you have your eye on. A good wrench can hear and spot potential issues without having fancy HP tests and oil analyses...

Rod
Rod I will disagree on that statement because I have been using oil analysis long before we even heard of the internet, have used them for yrs on heavy equipment and also if you run a tractor 300 hrs before changing oil I wouldn't want it anyway and a good analyisis can tell ya lots of important things
 
A 6430 is a darn nice tractor. I was thinking we were talking about a 4020 or some kind of older tractor. Something that new shouldn't and likely won't have any problems. Should there be any problems, you've got a warranty there. We run a couple 6400's and a 6420 and absolutely love all three. Wouldn't trade them for anything, except maybe a 6430? :D
 
Thanks for more responses. May need to make an new post but has anyone had any dealings with Powergard Warranty. I agree Novaman I've been around 6110, 6420's and had really good look with them. This is my first tractor purchase and a little nervous just want to make a good decision.
 
Angus Cowman":2mbxhbjy said:
also if you run a tractor 300 hrs before changing oil I wouldn't want it anyway

Well lessee, I have a 4020 JD with 18,000 hours on the original engine, a 930 Case with 14,000 hours on the original engine, an 1135 Massey with 7000 showing on the clock, and 1130 with 12,000 on the clock, and a 2470 Case whose hourmeter stopped working at 9765. All original engines. The 24 doesn't burn a drop of oil. The 1130 uses 1/2 litre between 400 hr changes. The 1135 came to me burning 1 litre every 100 hours and its still burning 1 litre every 100 hours when haying. I change it every 300 hours because its being used more heavily. The 930 uses 1.5 litres every 400 hours. The 4020 doesn't see much use anymore, so I really don't know what its using.

300 hours between oil changes is NOTHING for a tractor thats being used. Hell, if we changed more often, we'd be changing oil constantly. We'll have 400 on the 24 just seeding, and we're not going to stop seeding to dump the oil again. It'll get done after season. My customers that seed 10 or 12000 acres sure as heck aren't dumping oil every 200 hours. Many of the 4WDs will get a change at the start of seeding and not see a change for 4 weeks of steady 18 hour days.

You can believe what you want about oil analyses. I know better. I had customers that used the $18.95 oil analyses and got false reads. I rebuilt three 5.9s because the customers had bad oil reads come back. When I pulled them down, they were PRISTINE.

Rod
 
I had customers that used the $18.95 oil analyses and got false reads. I rebuilt three 5.9s because the customers had bad oil reads come back. When I pulled them down, they were PRISTINE.

I am sorry Rod wasn't meaning the $18.95 oil analysis was meaning the good ones from a reputable lab or dealer that sends them off I usually went thru Cat on my oil analysis and if I remember correctly they were $150 to $200 for the test. sorry about the misunderstanding
 
Angus Cowman":a3vlfaon said:
I am sorry Rod wasn't meaning the $18.95 oil analysis was meaning the good ones from a reputable lab or dealer that sends them off I usually went thru Cat on my oil analysis and if I remember correctly they were $150 to $200 for the test. sorry about the misunderstanding

Ah, yeah thats a different story. I don't have a big problem with tests run by a reputable lab, although you really do need a clean oil baseline as well as several reads all in a row before you can get truly useful information. Its odd, but you take 5 identical engines, run the same oil through them for the same hours, and you'll get different analyses back for each. Casting differences, tolerances, etc will all be different so you'll end up with different reads. If you do end up with the same reads between two engines, one of the engines may be on its way to a failure, while the other is just fine. You really don't know for sure unless you've had multiple reads for the same engine.

If someone is concerned about particulate matter in the oil, after you do an oil change, stick a magnet in the oil overnight. Check it in the morning and see what you have. Also cut open the oil filter and see what you can see.

Rod
 
DiamondSCattleCo":3sdvo7jd said:
Angus Cowman":3sdvo7jd said:
also if you run a tractor 300 hrs before changing oil I wouldn't want it anyway

Well lessee, I have a 4020 JD with 18,000 hours on the original engine, a 930 Case with 14,000 hours on the original engine, an 1135 Massey with 7000 showing on the clock, and 1130 with 12,000 on the clock, and a 2470 Case whose hourmeter stopped working at 9765. All original engines. The 24 doesn't burn a drop of oil. The 1130 uses 1/2 litre between 400 hr changes. The 1135 came to me burning 1 litre every 100 hours and its still burning 1 litre every 100 hours when haying. I change it every 300 hours because its being used more heavily. The 930 uses 1.5 litres every 400 hours. The 4020 doesn't see much use anymore, so I really don't know what its using.

300 hours between oil changes is NOTHING for a tractor thats being used. be nice, if we changed more often, we'd be changing oil constantly. We'll have 400 on the 24 just seeding, and we're not going to stop seeding to dump the oil again. It'll get done after season. My customers that seed 10 or 12000 acres sure as heck aren't dumping oil every 200 hours. Many of the 4WDs will get a change at the start of seeding and not see a change for 4 weeks of steady 18 hour days.

You can believe what you want about oil analyses. I know better. I had customers that used the $18.95 oil analyses and got false reads. I rebuilt three 5.9s because the customers had bad oil reads come back. When I pulled them down, they were PRISTINE.

Rod
What kind of oil are you using? Synthetic?
 
novaman":2t5nm8u0 said:
What kind of oil are you using? Synthetic?

Naw, I run a good dino oil. I personally use PetroCanada Duron 15w40 (10w30 in the winter). By the time synthetic oil was affordable and mainstream, most of my tractors had thousands of hours on them and I was hesitant to switch to a higher detergent synthetic. If I ever buy a new tractor, I will switch to synthetic immediately. Many guys are putting 500 hours on synthetic changes with no ill effects. I personally think thats pushing it, but their engines are holding just fine.

I believe the secrets to long diesel engine life are as follows:
1) run high end oil. Not necessarily synthetic, as many synthetics aren't as good as PetroCan Duron or Shell Rotella. Stay away from cheap crap oils like WallyWorld or Co-Op branded stuff.

2) Keep air and fuel filters clean. People don't seem to understand how much crap gets into the cylinders on the air side.

3) Use only high end filters. Leave the Wix, Napa and Fram filters on the shelves. Buy either manufacturer branded, Fleetguard or Donaldson.

4) Let the tractor warm up for a while before using it.

5) Let the tractor cool down for a bit when done.

6) Always run a tractor at its recommended operating temperature. That'll be somewhere between 160F and 210F. Running colder causes cylinder wall wash. If you have to, cover it the engine in, even in the summer time.

7) Pick an RPM that gets the job done and stay there. Keep your foot off the foot throttle. Diesel engines don't appreciate variable revs. Make sure the RPMs you choose are "comfortable" for the engine. By comfortable, I mean choose a place where the torque is enough to do the job at hand. For loader tractor work, you may have to go several hundred RPM past that point. But you shouldn't be running redline or even rated PTO for loader work. There is simply no need, unless you don't have enough HP.

Rod
 

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