Replacing Hydraulic Fluid in Bobcat

I just purchased a 2005 Bobcat T190 and since I don't know what hydraulic fluid is currently in it or how what condition it is in, I would like to drain and replace it. The manual says to pump it out of the reservoir tank, however the specs say the the system holds 8.5 gallons and the reservoir holds 4.8 gallons so by doing this I would only remove around a third of the fluid. Is there some easy way to get more of the fluid out so that I replace more of it? I expect that the more new fluid I mix with the old, the better off I am. I assume I could pump it out the auxilliary connection, but I worry about pumping out too much and damaging something.

Any ideas?

Thanks,

Paul

Hi, Paul. Welcome to HEF. I have a 2001 773 G--many common components with your T190, and several excellent threads on HEF to help you with your model.

I can't resist your question. Somebody may have a better idea. What we do is get the machine stuck down in the woods or in a swampy place at the farm, 35 degrees and pouring rain, and then have a main hydraulic hose rupture while running at full throttle. Be sure to only fix the one hose, so another one can rupture again soon.

That'll do a good job of getting the old out and the new in. Now, we'll wait to hear how real mechanics do it. :beatsme

Yes, the reservoir holds roughly 5 gal, and the system total holds more. The thing is, unless you want to disconnect every component and hose on the machine to drain the oil, then it's near impossible to drain all the oil. Even if you pump it out the auxiliary circuit you still wouldn't get all the oil that's in the system. Likewise, even if you choose the auxiliary method, all you're doing is draining the tank. Once tank is empty you'd only pump maybe 1/2 gallon until the pump cavitated, not much gained there. Instead, drain the tank and change the filter frequently.

Dr. Jim,

I like your method, unfortunately I do not have a swamp nearby and it is still a little warm here and I expect this method doesn't work right unless conditions are just right I guess, I'll just follow the manual.

Paul

DrJim said:

Hi, Paul. Welcome to HEF. I have a 2001 773 G--many common components with your T190, and several excellent threads on HEF to help you with your model.

I can't resist your question. Somebody may have a better idea. What we do is get the machine stuck down in the woods or in a swampy place at the farm, 35 degrees and pouring rain, and then have a main hydraulic hose rupture while running at full throttle. Be sure to only fix the one hose, so another one can rupture again soon.

That'll do a good job of getting the old out and the new in. Now, we'll wait to hear how real mechanics do it. :beatsme

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ptrotter said:

Dr. Jim,

I like your method, unfortunately I do not have a swamp nearby and it is still a little warm here and I expect this method doesn't work right unless conditions are just right I guess, I'll just follow the manual.

Paul

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We could loan you one of our "operators" they seem to have the "break down in the worst place" system down pat!

To op, do you have a large "3/4 iirc" Allen? That is what you will need to get the top plug out of the tank? Do you have a pump of some kind? These are the two things you will need to pump the oil out.

Or second option, do you have a quick connect fitting with a hose to connect onto the coupler that you can run the fluid into a bucket? That is what you will need to do it with the aux Hyd. JJ.

Thanks,

I have right tools and a pump as well as a quick connect with a hose so I should be OK either way.

Paul

Hardline said:

To op, do you have a large "3/4 iirc" Allen? That is what you will need to get the top plug out of the tank? Do you have a pump of some kind? These are the two things you will need to pump the oil out.

Or second option, do you have a quick connect fitting with a hose to connect onto the coupler that you can run the fluid into a bucket? That is what you will need to do it with the aux Hyd. JJ.

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ptrotter said:

Thanks,

I have right tools and a pump as well as a quick connect with a hose so I should be OK either way.

Paul

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I would pump it out then. It will also give you the opportunity to have the cab flipped over and look around.
If it has the hydraulic fan drive you will be under there for the filter anyway.

Thanks, I'll do that. I have the filters that need to be replace under the cab, so I have to lift it anyway.

Thanks for everyone' help

Paul

Hardline said:

I would pump it out then. It will also give you the opportunity to have the cab flipped over and look around.
If it has the hydraulic fan drive you will be under there for the filter anyway.

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All the joking aside, we have indeed had two separate failures on the 2001 773 that effectively "drained" much of the older hydraulic oil. It's great fun changing a main drive hose out in the field. (Willie59 always works in an climate-controlled shop. )

While you are servicing your machine, I suggest that you inspect all of the hoses under the cab for signs of damage/abrasion from rubbing. The hoses "surge" with the changing directions and pressures. I find that some of the main hoses are maybe 1-2" shorter than I would make them, with the machines often coming from the factory with the main drive hoses lying against sharp corners of the various cases and housings in the compartment.

When I once went to buy a new hose--it was a cheap to buy the Bobcat hose as to get one made that particular day--the parts person mentioned the "hose protector" kits. Bobcat has some hard plastic pieces that zip-tie to the hoses in those places where they tend to rub. You can make your own, and maybe save the stuck-in-the-swamp-mountain-or-woods fate. And no, Bobcat had no explanation as to why they list the hose protectors for those applications in the parts fiche, but don't bother to install them at the factory. Fool me once. . . I'm sure we'll have hose failures again, but there are two hoses on my machine that are now protected from rubbing.

And no, I wasn't smart enough to do this until after the second--and avoidable--hose failure. Nothing like buying 5 gal or more of premium hydraulic fluid. . . twice. . . to teach one a lesson.

Thanks, I'll inspect the hoses while I am in there.

DrJim said:

When I once went to buy a new hose--it was a cheap to buy the Bobcat hose as to get one made that particular day--the parts person mentioned the "hose protector" kits. Bobcat has some hard plastic pieces that zip-tie to the hoses in those places where they tend to rub. You can make your own, and maybe save the stuck-in-the-swamp-mountain-or-woods fate

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If you have a good NAPA parts guy they also sell those, I don't have the numbers at home.

Just go to www.napaonline and enter hose protector in the search box.

I have changed oil after a repair buy running the auxiliary circuit with one hose in a bucket to catch oil and another sucking fresh fluid it seamed to work.

cdm123 said:

I have changed oil after a repair buy running the auxiliary circuit with one hose in a bucket to catch oil and another sucking fresh fluid it seamed to work.

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I have tried this method but found the return side did not suck the fluid back into the machine. I had to mount the supply bucket overhead so gravity helped the return line. then watched so I did not pump more fluid out then was returning. not hard but time consuming.