Using hydraulic fluid instead?
Elder User
Joined: Jul 2010
Posts: 610
Likes: 0
From: Sequim. WA
Hydraulic Fluid
If you mean mil-h- 5606 and its dirivitives then I warn you, don't.
Use what the manufacturer designed it for. Go synthetic for the best if you want. It has better temperature tolerance.
Use what the manufacturer designed it for. Go synthetic for the best if you want. It has better temperature tolerance.
Elder User
Joined: Feb 2006
Posts: 765
Likes: 1
From: Eastern Ohio
Wow. That stuff has an unpressurized flash point of 195f, 275f under pressure.
I suppose if nothing else you would watch the trans temp alot closer.
I suppose if nothing else you would watch the trans temp alot closer.
Elder User
Joined: Jul 2010
Posts: 610
Likes: 0
From: Sequim. WA
Hydraulic Fluid
Whats the point?
You could also run water if you lived where it would not freeze. Or JP 4 even.
I have worked with hydraulic fluid for 30 years and even the aircraft companies don't like it.
I used it in my boat trim tabes just because I have lots of it.
By the way, there are two types of hydraulic fluid. 5606 is one of them. The other is much newer design and not near as flamable. I can't remember its mil spec number right now but it is much more expensive.
Try it is you want. It is not that it won't work but it won't work better than synthetic ATF.
You could also run water if you lived where it would not freeze. Or JP 4 even.
I have worked with hydraulic fluid for 30 years and even the aircraft companies don't like it.
I used it in my boat trim tabes just because I have lots of it.
By the way, there are two types of hydraulic fluid. 5606 is one of them. The other is much newer design and not near as flamable. I can't remember its mil spec number right now but it is much more expensive.
Try it is you want. It is not that it won't work but it won't work better than synthetic ATF.
Elder User
Joined: Jul 2010
Posts: 610
Likes: 0
From: Sequim. WA
Hydraulic Fluid
Actually, now that I think about it there are more than two kinds of hydraulic fluid. I forgot that commercial aircraft run SkyDroil. Now that is some nasty stuff.
And don't mix them or the seals will disolve.
And don't mix them or the seals will disolve.
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Post Fiend
Joined: Feb 2002
Posts: 10,600
Likes: 3
From: Carhenge
Hydraulic oil is almost exactly the same price as ATF. So what's the reason for running it instead of ATF?
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Cargo Master
Joined: May 2010
Posts: 3,047
Likes: 10
From: Snohomish, WA
I have been working with all types of hydraulic fluid for 25 years. MIL-H-5606 is used primarly for storage or general wiping of aircraft landing gear. The military uses Mil-H-83282 and it has a much higher flash point. Commercial aviation primarly uses Skydrol or HyJet hydraulic fluid. That is nasty stuff and will strip paint off of everything it comes into contact with.
Using any hydraulic fluid from a farm supply will most likely not harm anything as is usually vegitable based. That means it would not hold up well to heat in a transmission. Although it may smell nice when you rebuild it.
Transmission fluid is purpose built for a specific job. The seals in the transmission are also designed to not react with the fluids. I have bought many gallonsof hydraulic fluid and I am pretty sure that Mercon 5 is the cheapest fluid I have bought. A couple gallons of hydraulic fluid at the tractor store just cost my neighbor $120 for his Kubota after we rebuilt his pump. I am pretty sure trans fluid is cheaper than that.
Using any hydraulic fluid from a farm supply will most likely not harm anything as is usually vegitable based. That means it would not hold up well to heat in a transmission. Although it may smell nice when you rebuild it.
Transmission fluid is purpose built for a specific job. The seals in the transmission are also designed to not react with the fluids. I have bought many gallonsof hydraulic fluid and I am pretty sure that Mercon 5 is the cheapest fluid I have bought. A couple gallons of hydraulic fluid at the tractor store just cost my neighbor $120 for his Kubota after we rebuilt his pump. I am pretty sure trans fluid is cheaper than that.
Post Fiend
Joined: Feb 2002
Posts: 10,600
Likes: 3
From: Carhenge
Most tractors and industrial equipment have torque converts but no clutch packs like an automatic, which is why I am doubtful they would work long term as an transmission oil for us.
Cargo Master
Joined: May 2010
Posts: 3,047
Likes: 10
From: Snohomish, WA
We used quite a bit of vegetable based hydraulic fluid. It wasn't anymore expensive and it didn't cause as much trouble when spilled. Pretty much used it in large systems though. Also used it in tractors too.
Quite a few different ones out there, here is the first one that popped up on Google.
Hydro Safe Oil: Biodegradable Hydraulic Oil
Quite a few different ones out there, here is the first one that popped up on Google.
Hydro Safe Oil: Biodegradable Hydraulic Oil
Elder User
Joined: Feb 2006
Posts: 765
Likes: 1
From: Eastern Ohio
Super UDT? I have a Kubota that runs that pricey stuff. Nothing else currently available meets the specs. I have seen some reports by other people trying fluids that where close and all had noticeable decreases in performance.