Backhoe attachment.

[North Idaho Wolfman]

In your 1975 to 1981 L285, your not running SUTD2 (Synthetic fluid), I would be surprised if it even has UDT in it, unless you did it.
It's a simple tractor, with simple fluid, keep it that way.

The amount of fluid in the cylinders of the BH is going to be minimal and trying to drain them is going to be a real challenge.
Take a sample if it's clean move on.

Yes you can hook it to the tractor...I said that earlier... But the performance of the BH is probably going to be minimal, but at least you'll know it all works.

You would be trying to run the BH off of remote valves that further restrict GPM available for the BH to operate with.

 

[countryroads]

Sounds good. Thanks Wolfman.

 

[countryroads]

The type of oil I have in my tractor is a Walmart brand called TDH (universal tractor fluid)

 

[North Idaho Wolfman]

Unless there is water in the hydraulic fluid (which is rare), your's not going to run much of a risk of contamination or fluid incompatibility.

 

[countryroads]

In my Kubota shop service manual it says that in order for the hydraulic pump to be in good condition, the discharge pressure should be between 13240 to 14690 kPa ( 1920 to 2130 psi ). I don't suppose these specs could be converted into gallon per minute?

 

[shootem604]

Pressure and flow are different things. You can have a line doing 100GPM at 1 PSI and another doing 1GPM at 100PSI.

 

[countryroads]

Ok. I understand. any progress with the Kubota dealer on that bigger hydraulic pump.

 

[North Idaho Wolfman]

A bigger hydraulic pump is only part of the issue, you would have to redo all of the piping for it to be able to flow more too.

A 7.8 GPM pump requires a 1" inlet and a 3/4 outlet with corresponding lines.
Your L285 most likely has 1/2 or smaller lines, and I'll bet you valves are the same.

 

[100 td]

A bigger hydraulic pump is only part of the issue, you would have to redo all of the piping for it to be able to flow more too.
A 7.8 GPM pump requires a 1" inlet and a 3/4 outlet with corresponding lines.
Your L285 most likely has 1/2 or smaller lines, and I'll bet you valves are the same.

@countryroads, Don't be too concerned about your piping, especially if you are going from a 3.7 to a 5.5 GPM factory style pump.

A 21GPM PTO pump that's likely 3 times too big for your requirements also uses the same size fittings as a 7.8 GPM or a 7.1GPM pump.

Fittings, that's all they are, they all share the same basic casting most likely!
And if you run a PTO pump the fitting and lines you run will have nothing to do with the tractor anyway, and you won't have to run 3/4 supply lines. A 3/8 pipe is .11 sq/in, a 3/4 is 4 times the size at .44 sq/in!

The factory supply pipe for the B21 backhoe is ~12mm external, hazard a guess at 1mm minimum wall so ~10mm or ~3/8" internal or smaller, and it works just fine straight from the factory, and runs somewhere around 7GPM IIRC.
The pump inlet is ~3/4, but uses a different filter setup than your tractor.
If you go from factory 3.7 to bigger at 5.5~6, it would be prudent to get someone with an L295 or other suitable tractor with that pump setup to see if their piping is larger than yours, and to what extent. Valves generally have some flow tolerance, one thing that will be noticed if you do upgrade the OEM pump, will be the speed of lift of your 3pt. You will have to use the valve a little more carefully to control the lift speed. The valve on the L295 is different to yours, but the L295 valve is used on many tractors with [FONT=&quot]3.7 to 6.3 GPM [/FONT] flow rates, based on data from tractordata (which really can't be relied on though). So I expect some variance may be fine with yours, something to explore further if you find out confirmed specs of other pumps from other tractors which bolt up.
EDIT: I haven't looked into your loader at all, if you have one, and of course the increased flow rate would also increase the speed of the loader, pipes and valves may well be suitable, but would also need to be checked. The speed increase on the loader would have to be considered carefully, depending on what you have, if any. Increased flow does not give the loader more lift capacity, just increase in speed.

 

[North Idaho Wolfman]

100 td...
Do you have any real world experience with this or are you just reading info?

Have you actually set up anything hydraulic?

Have you ever worked on a hydraulic system?

Just curious

I'll answer yes to all the above...

Ever wonder why they never put a larger pump on these tractors?
It's not for the lack of HP, it's the lack of fluid holding and cooling potential.
Uping a pump and running it on existing lines and valves that are designed for a smaller pump is a recipe of disaster, the system will overheat and failures will happen!

At this point Countryroads being able to simply change his current pump is a wild fantasy, there has no proof that a larger pump that will bolt on to and be usable even exists.
Maybe on fantasy island do these things happen but not where I'm from.

 

[100 td]

Uping a pump and running it on existing lines and valves that are designed for a smaller pump is a recipe of disaster, the system will overheat and failures will happen!

So if those models take the same pump, then yes you would be able to "upgrade" to a larger GPM pump.

I don't know what you are taking NIW, but it surely has taken you to fantasyland!

 

[shootem604]

Fight, fight!

In all seriousness gents, I didn't mean to cause any controversy with my posts - I was just exploring what I had heard about a replacement pump having a higher GPM but still used in the same application and how it could help the OP. Let's not derail this.

 

[Jim Dandy]

100 td...
Do you have any real world experience with this or are you just reading info?

Have you actually set up anything hydraulic?

Have you ever worked on a hydraulic system?

Just curious

I'll answer yes to all the above...

Ever wonder why they never put a larger pump on these tractors?
It's not for the lack of HP, it's the lack of fluid holding and cooling potential.
Uping a pump and running it on existing lines and valves that are designed for a smaller pump is a recipe of disaster, the system will overheat and failures will happen!

At this point Countryroads being able to simply change his current pump is a wild fantasy, there has no proof that a larger pump that will bolt on to and be usable even exists.
Maybe on fantasy island do these things happen but not where I'm from.

Clearly you have got off track. There is no need for this.
James

 

[North Idaho Wolfman]

Clearly you have got off track. There is no need for this.
James

Clearly you missed the point, if your going to call me wrong be prepared to be questioned by it, simple as that.

This is another manufactures BH built on their specs for there equipment.

The OP does not have the original pump or the reservoir for it so an alternative is needed.

The OP has added a set of remotes that run off of the original hydraulic system, so they will be undersized to run a BH as it's not a BH loop, yes it will power it, but it will be slow.

I didn't mean to imply that shootem604's information was not valid or worthwhile, it is, it's just that at this point there is not concrete information to know if a larger pump exists, and that still brings us back to the point that the OP's tractor is not set up with a BH loop and would not be cheap to add one, and factory pumps are not cheap enough to just experiment with it.

A PTO pump and a Reservoir to match the pump is a safe and worthwhile investment.

Yes I misstated the proper size of pump in the beginning (I used the wrong tractor for the base of the issue), I read and answer 100's of posts a day and sometimes info gets mixed up, I'm human.

I've worked on thousands of systems and no the pit falls that they run into, for example, most sub market tractors and BH's have one major failure point, hydraulics!
They are undersized underequipped, and under powered, thus they overheat, work slow and lack the proper power to get the job done.
So trying to match that pitiful performance is a wasted goal.

If you take that unit and add the proper pump and the proper piping and filtering it will run cooler, it will have the speed to be useful and will have the power to work effectively.

 

[shootem604]

The pump was only one of the options I mentioned, only because the OP had already plumbed the connections. My backhoe has a PTO pump and reservoir, and I think it is the preferred option.

 

[shootem604]

Since this pump discussion, I've been chafing still about my slow FEL speed and have considered a pump for my front PTO shaft just for the FEL. Does anyone have information on the spline and information on a supplier? I think a higher GPM may resolve it for me, and I may just use the tractor's fluid reservoir.

I did find more information on a replacement pump 35110-76110 which may have more flow that than the original 3.7GPM According to this site, it produces 5.3 GPM (Tractor data says the L295 pump does 5.5 GPM, and this is the same part or should be) https://www.completetractor.com/hyd-pump-for-kubota-l185dt-35110-76100/