Do synthetics actually suck?

[cheesehead]

It seems the focus of this thread is on engine oil, but what about the hydraulic fluid (oil)? Diesel engine properties should have no bearing on this lubricant and the cost to change it in my tractor is 10x the cost of changing the engine oil. Can I extend the life of this fluid and skip a change along the line? If I can, I'll die a happy man.

 

[Garrabo]

I do use Amsoil heavy duty synthetic hydraulic fluid, Perhaps we should start a war, I mean a thread on this next, I would like to know a little more about it /forums/images/graemlins/smile.gif

 

[CT_Tree_Guy]

Hiya Cheesehead -

I've never heard of extended drain intervals when using synthetic hydro oil (like SUDT) instead of non-synthetic (like UDT). I'm pretty sure Kubota specifies the same interval for both oils. That has got me too wondering why.

Anyone know why synths allow for extended drains on motor oil, but not for hydro oil? Or do they?

 

[ByronBob]

In the end we beat this to death and it still comes down to personel preference...........

 

[kenmac]

For me, it's a little more than that.

 

[Charolais]

"Anyone know why synths allow for extended drains on motor oil, but not for hydro oil? Or do they?"

Not knowing for sure but I expect it's because of filtration. Every tractor I know of has the hydraulic filter on the suction side. The filter has to have high flow in order to keep enough fluid to the pump. Every hydraulic filter I've looked at is 25 micron or higher(for tractors). Engine oil filters are much lower. Like 10 micron and down. Then there's the moisture to deal with in a tractor hydraulic system.

Where I work off farm we have a portable filter system we use to extend drains on hydraulic systems. It filters down to what ever micron you choose. We just plug in on the system tank and start pumping until we've filtered all the oil in the system and then top off with new oil. After seeing how this system worked I built one for my tractors. Been just about a year since I started using it on my tractors. I plan to take a sample in March or April to see if I need to change hydraulic oil. What I built filters down to 3 micron and I have a water removal filter as well. I use my home made bypass filter about every 20-30 hours. I have opened the 3 micron side up 2 times and could see the filter traps what appears to be particles of the wet brake pads. It also keeps the oil from darkening or I should say the oil will darken and after I run the by pass filter it clears the oil up. So at this time it appears to be working but will know for sure after a sample/test. Also I've been able to remove some water from the oil. A test sample will also tell me if I'm removing enough water.

If this home made bypass system works out I won't change hydraulic oil as long as the test come back good. The filter that came on the tractor will be changed less often as well. Once I have some test results I'll post on the bypass for hydraulics. If it's working I'll post some pictures as well.

 

[CT_Tree_Guy]

Charolais -

Good lord that was an excellent post! Man, you just gave us all quite a bit to "chew on" right there, for SURE! Add an auxiliary hydro oil cooler to help keep the oil from breaking down, keep it filtered like that, and probably be able to confidently extend the drain interval. Pure genius. That is why I love this place so much - because you guys all know so much!

Hey, give yourself a raise and take the rest of the day off - you just earned it! /forums/images/graemlins/smile.gif

Great post,

John

Any counter-points to what sounds like a great idea?

 

[Charolais]

"Any counter-points to what sounds like a great idea?"

Haven't seen any yet. Both tractors combined have just over 15 gal. of oil. The bypass filters will last a longtime before being used up with that small volume of oil. The 3 micron filter is $9 and the water removal filter is $8 so the price of filters is low. The filter on the tractor should last longer. One tractor filter is $28 and the other is $13.

One tractor has a cooler. I use Amsoil so the oil doesn't get all that hot anyway. So I don't see heat as a problem.

Since I use the same brand and type oil in both tractors I just plug the bypass filter bank right in the remotes of each tractor and just pump away. I also have a side drain hose that I send part of the oil after being filtered back in the fill hole on the tractor, That way I can see if the oil is being cleaned. That is if it's dark enough to notice a difference.

 

[robison]

With regard to adding an oil cooler to prevent oil breakdown . . .

As I understand it from Mobil's tech support, synthetic oil will be 100% fine at a certain temp, then it crosses a threshold and goes bad very quickly. So it's not a linear thing, and unless the tractor runs near that threshold temp a cooler will be of negligible benefit.

It might he harmful in cold weather because it would slow warmup.

A filter would probably be a more useful add-on as someone above posted.

I don't know the specs for synthetic hydraulic fluids but the failure point for synthetic engine oils is high enough that you will get engine damage if the oil is that hot. And on modern cars oil coolers are added to help remove heat from the motor, not to keep oil temps under control.

I've never measured a tractor hydraulic system so perhaps some measurements on your machine would give addictional insight into this.

 

[cowboydoc]

I would not skip a change. The reason is condensation. You really need to change all of the fluids in a tractor at least every year. If you didn't want to change at the minimum do an oil test. Depending on the cost it may or may not be cheaper to do a test or change it yourself.

Just a hint to someone that wants to make alot of money. Make a home oil test. I'm sure it could be done.