Why No Hydraulic Filters On Most Older Farm Tractors

[SilentJ]

Why didn’t Old tractors have hydraulic filters ? The case could be made that those tractors didn’t have hydraulic systems, in the proper sense. They ran a cylinder at low flow and low pressure. You might not have consumed even 1-2 Hp in that system and even then it was very intermittent. You’d drive 10 minutes or a 1/2 hour in basically a straight line plowing (depending how long your field was) then literally use the hydraulics for maybe 3-5 seconds to raise the plow. Then you’d turn around and let gravity lower the plow.

Very intermittent usage and low power demand

Now the flows and pressures have gone up, out of necessity. Want live power steering all the time ? Want to be able to control the speed of your hydraulic functions ? Want to plant running a vacuum pump, AND a downforce system AND power steering all at once, MOSTLY on a CONTINUOUS basis where you might consume 50 Hp OR MORE in the hydraulic system ?

You’re not getting there with a sloppy gear pump that’s loosely tolerances enough to allow chunks of oil dry to pass through it

I do hydraulics for a living and have had, for 25 years. It’s shocking how bad many systems are with regard to cleanliness. The highest number of warranty claims (many justifiably denied) on Equipment is dirty oil.

I am happy to conduct a brief “school” on hydraulic contamination on this forum (probably not on Theo thread) if there is interest, but not to a crowd that believes it’s a conspiracy theory if that happened to be the case.

 

[RickB]

Why didn’t Old tractors have hydraulic filters ? The case could be made that those tractors didn’t have hydraulic systems, in the proper sense. They ran a cylinder at low flow and low pressure. You might not have consumed even 1-2 Hp in that system and even then it was very intermittent. You’d drive 10 minutes or a 1/2 hour in basically a straight line plowing (depending how long your field was) then literally use the hydraulics for maybe 3-5 seconds to raise the plow. Then you’d turn around and let gravity lower the plow.

Very intermittent usage and low power demand

Now the flows and pressures have gone up, out of necessity. Want live power steering all the time ? Want to be able to control the speed of your hydraulic functions ? Want to plant running a vacuum pump, AND a downforce system AND power steering all at once, MOSTLY on a CONTINUOUS basis where you might consume 50 Hp OR MORE in the hydraulic system ?

You’re not getting there with a sloppy gear pump that’s loosely tolerances enough to allow chunks of oil dry to pass through it

I do hydraulics for a living and have had, for 25 years. It’s shocking how bad many systems are with regard to cleanliness. The highest number of warranty claims (many justifiably denied) on Equipment is dirty oil.

I am happy to conduct a brief “school” on hydraulic contamination on this forum (probably not on Theo thread) if there is interest, but not to a crowd that believes it’s a conspiracy theory if that happened to be the case.

If you think an hydraulic system with a gear pump is only working when a function is used and these “old” systems are all low (<1000psi) pressure systems there’s not much need for you to take us to school.

 

[SilentJ]

If you think an hydraulic system with a gear pump is only working when a function is used and these ç™»ld systems are all low (<1000psi) pressure systems thereç—´ not much need for you to take us to school.

You answered the question. You want someone to make you feel indignant and justified as you scoff at what you feel are ç*¥nnecessary filtration.

Have fun.

 

[RickB]

I never said filtration was unnecessary. Never. Nice try.

 

[Texasmark]

Depending on the tractor, farmalls since the late 560's had decent filters.

Ford didn't! Glad they never plugged on the dozen I had/have over the years.

 

[rScotty]

Hmm... I did discover this thread until today, and no, I don't know for sure why there were no hydraulic filters on the gas farm tractors - although I have an theory. It does seems to me like they should have had....after all, filtration was well known at the time, and those old tractors weren't all that different from hydraulics today.

Even though their hydraulic systems only ran at about half the pressures used today, they were powerful systems with close to modern flow rates... So why no filter?
The requirements for accurate tight tolerances in control valves to feather and hold pressure were the same as today & that's an argument for a good filter system.
Plus since these were almost all what we call "open" hydraulic systems (here "open" means constantly circulating) then the the hydraulic pumps were always pumping oil through the system and back to the reservoir whether there was a call of pressure or not. And that's another argument for filters.

But somehow they got away with it. Our old JD 530 has what is basically a mesh strainer for the hydraulics and after 60 years and umpteen hours the hydraulics still work pretty much the same as new. It makes good pressure (about 1200 psi) and the loader valves will hold the FEL up for hours.

Here's my idea: It might have been because back then really good oil filtration was considered to be an aftermarket sort of thing. it wasn't uncommon at all for farmers at the time to plumb in an aftermarket cannister or bypass filter into cars, trucks, and tractors. We did that; and most everyone else did too. And then since people were doing it anyway, the manufacturers eventually began to offer it as a feature. Lighting was that way on tractors for a long time too.
rScotty