Why No Hydraulic Filters On Most Older Farm Tractors

[atsah]

A

Yet early hydraulic systems had no filtration which is the actual topic of this thread.

So sorry for going off topic, my apologies..

 

[deserteagle71]

Sorry, I did not intend to insult your almost 60 year old tractor

No apology needed - my John Deere did not take it as an insult! I was just asking a question - where would you make a distinction between a "new" and an "old" tractor. And that's because a bunch of the guys around here are into the real antiques - the 2 cylinder Johnny Poppers and others from the 30s and 40s - and consider my 60s John Deere a "new" tractor. As far as that goes, I considered my John Deere a "new" tractor until I got the Kubota and saw how far tractor technology had come in the intervening years. And that's when I realized my John Deere was an "old" tractor. But at least it has power steering and three-point hitch which the Oliver 70 that I started my tractoring career on in the 50s did not have!

 

[KennyG]

Until we had hydro drive tractors, I don't think there was much need to change hydraulic fluid, let alone filter it. I don't remember ever changing fluid in one of our old farm tractors and we never had trouble with them. I remember rebuilding several engines, but I don't think we ever replaced a hydraulic pump. It was just a much simpler system.

 

[CADplans]

THe old tractors were mostly gas tractors, with pretty simple hydraulic systems. Some were low pressure, as low as 8 or 900 psi. And really, I think it took time to show what was necessary. The modern, high pressure systems, have somewhat fussy valves that cannot take a lot of dirt.

They didn稚 know any better.

The generation of tractor before those did not even have an air filter on the engine,,,
just a tall pipe that sucked air from above the "dust" layer,,,

The same with oil,,
Drain the engine oil, store long enough to let the "dirt" settle out of the oil,, reuse the "clean" oil,,,

That was before detergent oil,,

 

[deserteagle71]

The generation of tractor before those did not even have an air filter on the engine,,,
just a tall pipe that sucked air from above the "dust" layer,,,

I remember an old Ford we had in the late 50s that had a big oil bath air filter on it. The air for the engine was drawn through a heavy steel mesh that was soaked in oil. I was alway amazed at how much gunk that filter collected in the pan below the filter. (That type of filter never needed replacing and it was my job to clean it.)

 

[torch1]

Most hydraulics are only filtered on the return to tank or reservoir. Most systems can probably handle about 600 psi max and these are metal encased filters used in transmission hydraulics.
With hydraulic systems running above 600 psi the restriction of a filter is just too much and the filter will blow apart, in this case say 2000 PSI systems, the latest system run above this as they are running piston style pumps and the pressures can be above 3000 PSI.

Screens and filters are a great resource for trouble shooting as the material in the filter will indicate what has failed. Same goes for engine oil filters, get a filter cutting tool and use it all the time.

If you should have a system failure you need to clean everything past the failure as no filter means you just contaminated the complete hydraulic system, this means, hoses, valves, pump, cylinders everything, if you do not, you risk a repeat failure and then you can do it all over again.

Oil, seals, filters, breathers, are cheap compared to hard parts like pumps, valves, cylinder, do not scrimp on maintenance.

Get yourself a manual and get to know your system, another good thing to do is check your system pressures when new. Write the data down as this is invaluable when trouble shooting a problem later.

If you do not have a filter you can build a filter cart that takes you oil and filters the oil then returns it to the tank or reservoir, great tool for older tractors and even some new ones.

Be very careful when adjusting and checking pressures as they require your strict attention to prevent injury.
This can happen any time you open any pressurized system.
SAFETY FIRST, STARTS WITH YOU.

 

[Chewwy]

Lots of good info but beyond the scope of the initial topic “why most older farm tractors had no filter on the hydraulic/transmission fluid system, relying simply on sump screens?”

 

[LouNY]

Lots of good info but beyond the scope of the initial topic “why most older farm tractors had no filter on the hydraulic/transmission fluid system, relying simply on sump screens?”

Low pressure, low volume, low sped, minimal uses and heavier oils used at that time, straight weight 30 engine oil.

 

[JDAOWNER]

PERHAPS AS WITH NEWER CAR ENGINS, THE MACHINING WHEN MAKNG THE PARTS FOR THE SYSTEMS ---MOTOR, TRANY, HYDO--HAVE SUCH CLOSE TOLERANCES WHEN MACHINING IT BECAME EVIDENT QUICKLY THAT A FILTER WAS NECESSARY.

 

[atsah]

PERHAPS AS WITH NEWER CAR ENGINS, THE MACHINING WHEN MAKNG THE PARTS FOR THE SYSTEMS ---MOTOR, TRANY, HYDO--HAVE SUCH CLOSE TOLERANCES WHEN MACHINING IT BECAME EVIDENT QUICKLY THAT A FILTER WAS NECESSARY.

That is without a doubt the reasoning behind modern filtering in tractors IMO..