Maintenance comment / question

[woodlandfarms]

Doesn't it seem like the oil filters get changed rather quickly in the PT's. I mean, I am replacing my Hydraulic filter every 50 hours. Terry says Engine at 100 and Fuel at 500.

On a car, 50 hours @ 50 mph is 2500 miles. I guess that is old school filter changing times...

But my engine is at 100 hours (with oil change) although the engine manual says 500 hours in dirty conditions. I am using synth so I am thinking 250 hours on my engine change. It is weird how black the oil gets immediatly, but I guess it is a diesel.

Fuel is at 1000 hours according to the Deutz manual.

So what I am getting at is there is a major discrepency between Deutz and PT. I do not mind being cautious, but there is cautious and then there is wasteful.

Also, what is the proper time to change out Hydaulic oil (not the filter, the oil).

Looking forward to some insight on this.

edit

So, I just saw some fine print in the Deutz Manual. "maintenance in chart is maximum values - please follow operating instructions of equipment manufacturer". Now here is a legal weirdness. Wouldn't PT be obligated to suggest maintenance in writing? They are all wound up about no photos at their factory for "legal reasons" it seems kinda stupid not to document maintenance items for warranty purposes.

 

[MossRoad]

We change the oil and filter in our car every 2500 to 3000 miles, so its not that different changing the hydraulic filter that often.

 

[woodlandfarms]

But now cars are saying 5K and some are saying 10 or more. Studies are showing that oil is good for quite a bit longer than the oil companies wanted us to know. I know it is a lot about precision of manufacture, and there is a difference between diesel and gas, but this is hydraulic...

I mean in the grand scheme of things I will continue to do it until someone says change, but

 

[ponytug]

Dear Carl,

You raise a number of issues. Yes, 50 hours is the equivalent of 2500 miles @ 50, but think of the difference in exposure to water, dust, and just plain grit. You want to keep an eye on the oil behaviour so that you know when you are developing excess blow by. Different diesel are more or less prone to blow by. The old navistar 7.3l diesels have a lot of blow by, but they seem to run forever, so blackness isn't necessarily evil, since a little bit of carbon black will color a lot of oil. If you have a lot of black oil immediately after an engine oil change, you may have an excess of sludge on the bottom of your oil pan that is overwhelming your oil's detergent capacity. MY PT is too new to have any idea of how these engine run for black oil. The old ('80s vintage) Deutz's got pretty black, but emission standards have tightened up a lot since then.

Deutz's legalese is pretty straight forward; you should change the oil filter at least as frequently as they suggest, but more frequently if the equipment manufacturer, e.g. PT, suggests it. This is deferring to the knowledge of the manufacturer about the true operating environment. Again, dust, and water are really tough on oils. Your PT is out in the wet, salty air of the PNW, and probably could use a relatively frequent oil change.

Buried in my pickup manual is the required maintence of re-greasing the U-joints daily if operated in mud or water. I don't know a 4WD enthusiast who actually does it. Then again, the major threat to most of their trucks isn't wearing out.

I guess that what I am suggesting is that the PT are used under rather harsh conditions of dust, grit, and water, all of whom eat into equipment lifetimes. Synthetic oil doesn't help much with sand, but filters do, and you want to change the filter before it goes into bypass mode. Could you go longer? Probably, but you would want to monitor oil quality, and the oil filter pressure differential at a minimum. If you go longer, you might want to consider adding a second engine oil cooler, or upgrading to the ag oil cooler that Mike OConnor mentioned awhile ago to help keep the engine oil cool, and therefore unfried.

In a prior post, I mentioned that for fun, I let my 100 hour filter drain, and discovered lots of fine metal particles in the oil coming out. I would much rather have the filter changed often, and the particles out of the system.

If you are really losing sleep over it, have some oil analyzed. My bet would be that the oil itself is in OK viscosity shape, with some acidity, but you will have lots of wear particles caused by dirt, which are probably giving the detergent a work out. The same is probably true for your hydraulic oil. (Cue Jaws music, and the rereading of the posts on why you might, or might not, want a detergent oil in your hydraulic fluid.)

In the case of hydraulic fluid, you would probably want to change the hydraulic oil when you start to lose some of the additive chemistry, since loss of detergent chemistry isn't quite the issue it is for an engine. However since your hydraulic filter is an intake filter, if your hydraulic filter ever clogs, it would collapse, sending who knows what kinds of debris into your drive pump, which would more less wipe the drive pump out. Personally, I'd rather change a few too many filters, rather than deal with that certainty. But again, a differential pressure gauge would let you know when it is clogging up-be sure to read it at WOT cold for worst case.

I can see it now, a computerized dashboard with remote pressure sensors, warning lights and alarms to let you know when the various filters are nearing their change limits. You could probably do it with three differential pressue transducers and a NEMA4X triple pressure guage, with programmable alarms to let you know when to change various filters and oils. Perhaps you have a buddy over in FX that could rig you up a waterproof touch screen version? Maybe redo the paint job? Perhaps add a flame thrower for the really tough blackberries? Or....

All the best,

Peter

 

[ponytug]

Yes, but this is for high precision automobiles that leak very little gunk into the oil, and are driven out on the wide open, clean, interstate.

Water, dirt, dust and stop and go, all cut into that high mileage oil change interval, and we have all four.

Other factors also trigger earlier oil changes, e.g. 5% Biodiesel alone cuts the oil change interval in half for the new Navistar diesels.

Basically, I think off road equipment is very hard on oil for dust and dirt reasons alone.

All the best,

Peter

But now cars are saying 5K and some are saying 10 or more. Studies are showing that oil is good for quite a bit longer than the oil companies wanted us to know. I know it is a lot about precision of manufacture, and there is a difference between diesel and gas, but this is hydraulic...

I mean in the grand scheme of things I will continue to do it until someone says change, but

 

[Bob999]

In the case of hydraulic fluid, you would probably want to change the hydraulic oil when you start to lose some of the additive chemistry, since loss of detergent chemistry isn't quite the issue it is for an engine. However since your hydraulic filter is an intake filter, if your hydraulic filter ever clogs, it would collapse, sending who knows what kinds of debris into your drive pump, which would more less wipe the drive pump out. Personally, I'd rather change a few too many filters, rather than deal with that certainty. But again, a differential pressure gauge would let you know when it is clogging up-be sure to read it at WOT cold for worst case.

There is an additional issue with the hydraulic filter mounted on the supply side. A dirty filter will reduce flow and can result in significant negative pressure (vacuum) on the intake side of the charge pump. If the charge pump does not receive adequate oil supply cavitation in the pump can occur with resulting damage. My opinion is that the potential for cavitation with a filter mounted on the intake side is the reason for the very frequent change interval specified by PT.

 

[MossRoad]

But now cars are saying 5K and some are saying 10 or more. Studies are showing that oil is good for quite a bit longer than the oil companies wanted us to know. I know it is a lot about precision of manufacture, and there is a difference between diesel and gas, but this is hydraulic...

I mean in the grand scheme of things I will continue to do it until someone says change, but

I agree that oil lasts longer than listed, but still do the changes at my 2500-3000 mile intervals. Why? Because we'v ealways done it that way!

I do have a 1985 lawnmower that has never had an oil change. It takes about 3-4 tablespoons of oil each spring. Still starts on the first pull each and every time.

 

[J_J]

Doesn't it seem like the oil filters get changed rather quickly in the PT's. I mean, I am replacing my Hydraulic filter every 50 hours. Terry says Engine at 100 and Fuel at 500.

On a car, 50 hours @ 50 mph is 2500 miles. I guess that is old school filter changing times...

But my engine is at 100 hours (with oil change) although the engine manual says 500 hours in dirty conditions. I am using synth so I am thinking 250 hours on my engine change. It is weird how black the oil gets immediatly, but I guess it is a diesel.

Fuel is at 1000 hours according to the Deutz manual.

So what I am getting at is there is a major discrepency between Deutz and PT. I do not mind being cautious, but there is cautious and then there is wasteful.

Also, what is the proper time to change out Hydaulic oil (not the filter, the oil).

Looking forward to some insight on this.

edit

So, I just saw some fine print in the Deutz Manual. "maintenance in chart is maximum values - please follow operating instructions of equipment manufacturer". Now here is a legal weirdness. Wouldn't PT be obligated to suggest maintenance in writing? They are all wound up about no photos at their factory for "legal reasons" it seems kinda stupid not to document maintenance items for warranty purposes.

This guy seems knowledgeable.

Get the hydraulic information you need!

 

[Wayne County Hose]

This guy seems knowledgeable.

Get the hydraulic information you need!

Hmm. This is the same guy that recommends taking your suctiion strainer out and throwing it away. I would be very careful about heeding his advice. I would like to find out how he knows more than almost every major manufacturers engineering department.

Carl, you want to change your hydraulic oil at least yearly for a variety of reasons, especially if you have an open system which I believe the PT has. A closed system is completely sealed, no air enters, no breathers. Basically only used on hydraulic systems with only motors and double acting cylinders that have a low volume as compared to the reservoir tank. An open system has a breather letting outside air into the tank to take the place of oil going into your cylinders. This outside air contaminates your oil with fine airborne particles. One thing you could do is to get a very good breather and keep them clean. If you went this route, I would get 2 and rotate them and clean them at your convenience. There is also condensation that forms in your tank from the heating and cooling cycles of your oil. The condensation is pulled into the tank with the air through the breather. With how fragile the hydraulic systems seem on these PT's, it seems like changing the fluid and filters would be cheap insurance to me. 50 hours seems like an extremely short interval to me, but I don't have one so I don't know. I guess if that's what PT recommends and I used the machine a lot, I would find somewhere and buy a case of them at a discount.

 

[J_J]

Hmm. This is the same guy that recommends taking your suctiion strainer out and throwing it away. I would be very careful about heeding his advice. I would like to find out how he knows more than almost every major manufacturers engineering department.

Carl, you want to change your hydraulic oil at least yearly for a variety of reasons, especially if you have an open system which I believe the PT has. A closed system is completely sealed, no air enters, no breathers. Basically only used on hydraulic systems with only motors and double acting cylinders that have a low volume as compared to the reservoir tank. An open system has a breather letting outside air into the tank to take the place of oil going into your cylinders. This outside air contaminates your oil with fine airborne particles. One thing you could do is to get a very good breather and keep them clean. If you went this route, I would get 2 and rotate them and clean them at your convenience. There is also condensation that forms in your tank from the heating and cooling cycles of your oil. The condensation is pulled into the tank with the air through the breather. With how fragile the hydraulic systems seem on these PT's, it seems like changing the fluid and filters would be cheap insurance to me. 50 hours seems like an extremely short interval to me, but I don't have one so I don't know. I guess if that's what PT recommends and I used the machine a lot, I would find somewhere and buy a case of them at a discount.

Either you or Casey need to go back to school on hydraulics. What he is actually saying is that if your tank is clean, you really don't need an input filter, but everyone knows, it is sometimes difficult to keep water and other contaminants out. Power Tracs hydraulic driven machines like WOODLANDFARMS and I and a bunch of others own , use a combination closed loop and open loop system. The drive system is closed loop system with a 10 micron filter on the input to the charge pump on the variable speed hydraulic pump, and is the only filter in the hydraulic system , the PTO and the steering uses gear pumps , all three pumps sharing a common reservoir. All the filtering for the complete system is the fluid going through the charge pump, which is a makeup pump, IE, making up the difference in the fluid lost through the drive motors via the case drains, and the case drains on the VSP pump..

Replace 20 gal hydraulic oil yearly, you got to be kidding, although it would be good for your business. Regular motor oil, at $3.00, would cost us $240.00 If you uses synthetic oils, at $6.00 a quart, the cost would be $480.00

On the subject of input filters, I think that I agree with him on the damage to the pump caused by suction restrictions caused by clogged up filters. Personally, I think each circuit should have it's own filter with alarms to indicate replacement. I think I would depend on an oil test to determine when to replace oil. The external filter units would also be a good idea on a weekly basis. Good tank filters are a must. Clean fluid with the right chemistry is the only way to get the longevity that we paid for. I don't know how long you have been in the hydraulic business, but common sense with a little knowledge goes a long way. By the way, do you own, and use any piece of hydraulic equipment? Do you actually go out to someones broke down hydraulic machine and diagnose the problem and fix it? Are you a salesman or a hydraulic technician/engineer?