1982 L245DT crankshaft splines

[Milo Holroyd]

looks like I need to find a smaller pump. I'm afraid any drive ratio change would move the pump too close to the ground. I'll keep at it.
Thanks for your help.
Milo

 

[Ob1kubota]

re: the heat /cavitation issue.
I was hoping to avoid that by not completely closing the bypass hose.
I am worried about too much aeration of the bypassed fluid.
The quest continues Thanks for the reply
Milo

Milo I'm in agreement with Ed assuming a 20 GPM pump is mounted to your crankshaft. This is getting so interesting but expensive too. I had to knock the dust off my Hedland Fluid Power Data book and look at the formulas ( refreshing!) I want you to think outside the box ( open minded ). Open the attachment and look at what you are in effect doing to the hydraulic fluid in your closed loop open center hydraulic system. Even an open loop system would create heat going over relief with a flow control valve, i.e.: ( your 'Tee' back into the transmission ).
Last thought tonight on this Post .... at least 25% of your available crankshaft HP is being lost to Heat generation converting Ed formula to BTU/ minute = .00039 HP. May be with an hydraulic oil cooler ( more cost ) and constantly working your cylinders ( hard to do this to keep heating rate in check ) it will live until your suction side collapses. Milo look at your overall goal with gpm needed with the work you'd like to do and size the system based on its restrictions.

 

[Milo Holroyd]

In retrospect, I should have sought info on the original pump specs.
Instead of using the "on hand" bigger is better approach.
Thanks for the reply. Good info.
Milo

 

[Milo Holroyd]

Ed, Ob1,
Could a log splitter type pump be considered for my project?
Single stage, two stage?
Thanks
Milo

 

[eserv]

A log splitter pump would be OK provided it's displacement was about 1.1 to 1.3 cc This will give about 6 to 8 usgpm at 2600 rpm which should be in the ballpark for your tractor. the higher GPM will make the hydraulics faster but will consume more HP so you have a tradeoff. Personally I see no advantage to two stage for you but I'd like to hear others opinions and feelings on that!
I'm a little rusty on my math not having sized any pumps in a while so maybe others can check that for me too!
Ed

 

[eserv]

I got my decimal point in the wrong place! Should be 10 to 12 cubic centimeters. ( .61 to .63 cubic inches)
Ed

 

[eserv]

The easiest and best way to fix your tractor would be to install a new original equipment pump. The part number for it is 3511076101. We will sell you one for $481.00 Canadian.
Ed

 

[Milo Holroyd]

Thanks for the offer, and help.
I agree, a new pump would be the easiest by far.
I guess I just like the challenge of using "parts on hand", when possible.
Milo

 

[eserv]

I here you! I'm often guilty of reinventing things or "improving" on the original design. Sometimes it even works! In your case you will improve the performance because the original pump wasn't designed for a loader so is low in flow. A somewhat larger pump will be great as long as the system can still handle the flow. 8usgpm would be maximum in my opinion though.
Ed

 

[Milo Holroyd]

Sometimes it even works! Ed

Hah! I love that. I'm going to comb through some other pumps I have around, and see what I can come up with.
I'll keep ya posted.
Milo

 

[eserv]

You know you could fire up that lathe you have and modify that pump so it isn't to big.

 

[Milo Holroyd]

Ya but then the ID would be larger than the OD Would leak like crazy.

Really though, I found another pump that I have high hopes for. I'm machining an adapter for the input shaft. Hope to try it out late tomorrow.

The pump specs are: .738CI/Rev, 2500Max PSI, 4000MaxRPM, GPM varies with RPM 1000=2.9GPM, 3000=8.6GPM. I just may have shot at this

Milo

 

[eserv]

Maybe just a little big yet, but I'd sure try it! You reduce the length of the gears to reduce the displacement of a gear pump. Some accurate machining required and the gears are quite hard but with patience and time it is doable!
Ed

 

[Milo Holroyd]

Well, here is pump number 2. Engine runs it just fine.
However, playing with my loader valve, I noticed that the oil does not seem to go straight through the valve, when the spools are all neutral.

Shifting either of the spool positions very slightly, completely unloads the pump.
Otherwise, the pump is always working. (I wonder if that's what wore out my original pump?).

Milo

 

[eserv]

Sounds like you might have a closed center valve on there. If so it will not work! Some valves have a plug you can change to convert from closed center to open center. can you post a picture of the valve?
Ed

 

[eserv]

Further thinking about your tractor I'm wondering if you could have the power beyond plugged. Do you have three hoses to your tractor from the valve?
Ed

 

[Milo Holroyd]

http://www.orangetractortalks.com/forums/showthread.php?t=790
There is a pic of my hoses in this thread.

 

[Milo Holroyd]

I have about a 1/4" of fore-aft movement in my tilt spool. Something has come apart, or is very loose. Most likely the return spring under the cover.
Milo

 

[eserv]

Looks OK "B" is Pump "c" is Tank and "a" is power beyond. Wouldn't be something as simple as the three point hitch going to high causing it to go over relief? You should be able to move the rockshaft up 1/4 to 1/2 inch with the three point hitch lever right at the back. ( you'd be amazed how many of these are out of adjustment!)
Ed

 

[Milo Holroyd]

I could use a tutorial on the Three Point Hitch adjustment.
I played with mine 2 years ago, (when my pump started failing), hasn't been right since.
Milo