ATF when to change

[Ronray]

When ATF automatic transmission fluid Dexron 3 is used in place of hydraulic oil, aside from the hour meter, how do you know when it's time to change that fluid? In my case, the machine is a 1980 marklift man lift that I purchased at an auction.

 

[Delmer]

You could get an SOS oil sample test kit from CAT and send a sample in as ATF in a hydraulic system. Otherwise, if the fluid doesn't have water, and doesn't foam, and you change the filter and inspect the old ones, then I really wouldn't change ATF in a manlift. You'd only change half of it without a lot of work, and you'd probably get more dirt in than out if you're not real careful.

Does the reservoir have a port to check the condition of the bottom? that will tell you as much as the old filters.

 

[kshansen]

You could get an SOS oil sample test kit from CAT and send a sample in as ATF in a hydraulic system.

I would agree with Delmer pretty much unless this is a machine you are going to be putting 2,000 hours a year on and depending on for your source of income.

Even at that sampling and filters would be more important than replacing the oil that is in the tank and still having all the old oil in the lines and cylinders!

 

[Ronray]

Wow, thanks for that great advice. My man lift is just for my personal use around my house , which has a lot of tall trees that need to be pruned, so I would be putting very few hours on the machine, and I assumed that I would shut the motor off once the basket was in position and I was doing my pruning. So I would assume that since these are two way cylinders, that there would still be quite a bit of old oil in the cylinders even if they were in the retracted position. The color of the existing old ATF oil is kind of a dark red color. So I'm assuming then that it is still useful and will not damage the cylinders or seals, even though the new ATF oil I am adding is kind of a light colored red?

 

[kshansen]

Taking a sample with oil warmed up good is still a good idea. I forget what say the local Cat dealer would charge but probably not more than the cost of the filter and a gallon of oil and if it comes back with good report then the peace of mind would be priceless.

It would also be a good idea to do a sample test at least once a year just to keep up with any changes. In oil samples trends are many times more important that just raw numbers from one test.

 

[Ronray]

Well, here is the atf Dex3 oil report. Any comments? Does it need changing?

 

[Nige]

If that was a sample taken with warm oil, the following comments........
No high levels of metals (Cu, Fe, Cr, Al, Pb, Sn) - check.
Silicon (dirt) in single figures - check.
Good levels of friction modifier additives (calcium & zinc)
ISO Cleanliness Code 17/12, pretty much the same as the standard for clean fill oil (16/13).

I don't know what other people think but I wouldn't even consider changing that oil.

 

[kshansen]

Been too long since I looked at sample reports to comment with any good authority, but when silicon is in single figures that make me happy for sure. That said as Nige said the key thing would be was machine worked enough before pulling the sample to get things mixed up good?

I could take a jug of muddy water that was so bad you could almost walk on it and let it set for a week and carefully scoop some off the top and it would look nice and clean. But put it in a blender for five minutes and I don't think you would want to drink it.

Not trying to find fault with how you sampled it, as we have no idea of that, just explaining to you and anyone else who might be reading this how important it is to "shake well before using" or in this case pulling a sample!

Next thing I might suggest is to do a follow up sample after you have had time to use the machine for a few months. One of the most important things in samples is the trends of the various levels.

 

[Ronray]

Thanks for that great advice! Actually the sample was not from warm oil. The 40 gallon tank only had 12 gallons in it, which I drained into five gallon buckets. And I took the sample from the top of the first 5 gallon bucket after it had set for a week or so. In the meantime, I made sure the inside of the tank was spotless clean and I added 25 gallons of brand new ATF fluid. But I was thinking of adding back in some of this older fluid that the sample was taken from, maybe just the upper portion of each bucket? I did not find any debris that had settled to the bottom of those buckets of old oil.

 

[kshansen]

In that case I would suggest a second sample after a goo long run time and taken from machine while it is running. Cat sells nice fittings you can tee into say a filter head and use a needle like you use to fill a football with to grab a nice sample while machine is running.

I might be able to find a part number if you can't get it from Quinn, but I'm sure they will be able to help you.