Green Case Loader

[Harry]

Pulled the pump apart this morning after a bath in the parts washer. Looks good with limited wear on the gears and pump body. Guess I’ll put it all together and pay close attention to the lovejoy connection. Still not sure why the drive motor and loader lift arms would intermittently work. Harry

[Spike188]

@Harry is there wear on the end plates and a bit of pitting on them?

[JSinMO]

I’ve had a couple of gear pumps apart but they were both obviously bad. One was one my Case 830 and luckily I was able to have it repaired as they are hard to find. The other one is still in pieces in a box somewhere on a shelf in the shop! Not sure why I kept it!

There should be a procedure to check tolerance on that while you have it apart. I’m hoping someone on here can let us know what the tolerances should be and the process.

I’m interested in what you find, you’re making great progress on this tractor!

[myerslawnandgarden]

Harry,

Most worn pumps do not exhibit the intermittent operation that you mention unless there is a problem with the lovejoy coupling. Based on your documentation, the coupling halves look good. The most worn out pump that you will ever find still provides the rated flow (which is the cubic inch displacement between each gear cavity x the rpm of the input) until a load is applied which causes the output flow to drop, slowing the movement of the tractor, lift etc. Not intermittent flow, just slower flow.

My suggestion would be to check for a restriction on the suction side of the pump, possibly a suction hose which is delaminating on the inside. Also, most of the hydraulic reservoirs had a baffle inside to keep oil at the reservoir outlet during hard turns. I have seen the spot welds securing the baffle break letting the baffle float around and block the reservoir outlet.

Just a thought,

Bob

[Harry]

@Harry is there wear on the end plates and a bit of pitting on them?

They are actually just dirty. The hydraulic oil I removed from the system was very nasty. Harry

[Harry]

Harry,

Most worn pumps do not exhibit the intermittent operation that you mention unless there is a problem with the lovejoy coupling. Based on your documentation, the coupling halves look good. The most worn out pump that you will ever find still provides the rated flow (which is the cubic inch displacement between each gear cavity x the rpm of the input) until a load is applied which causes the output flow to drop, slowing the movement of the tractor, lift etc. Not intermittent flow, just slower flow.

My suggestion would be to check for a restriction on the suction side of the pump, possibly a suction hose which is delaminating on the inside. Also, most of the hydraulic reservoirs had a baffle inside to keep oil at the reservoir outlet during hard turns. I have seen the spot welds securing the baffle break letting the baffle float around and block the reservoir outlet.

Just a thought,

Bob

Thanks for the input Bob, I will certainly check the hose and tank for the baffle. I do know the suction hose is a double hose with wire braid inside. It was very hard to get off the pump and cut my hand from the wire. Tank side was not so difficult to remove. A few days off of this project and I’ll dive back in. Harry

[Harry]

It’s getting closer to fired this little GT up again. The throttle and choke cables never worked correctly so I found some time to fix the situation yesterday. I had a throttle choke cable laying around from some old machine. So I used that and now seems to be working smoothly. Harry

[Harry]

Today I put the battery back in connected the cables turned the key, nothing. Pulled the battery and started checking wires and found one from the positive side of ammeter not connected. Checked a few other wires from relay, voltage regulator according to a wiring diagram and these are all messed up. Before I got into the hydraulic pump and lovejoy this GT started and ran. So I pulled all the wires off the switch, relay and voltage regulator. Started to rewire according to the diagram and color code. This is not what I expected, but I will know that it is correct when done. Harry

[propane1]

That’s sorta strange Harry, could be Gremlins.


Noel

[Harry]

The ignition switch has been rewired and it runs fine. I think it’s time to step away from this project and concentrate on the 646 cab. Installed the hood with light wiring done, took a few pics and switched places with the 646. Musical GT’s yesterday moving three out if shop, then two from lean to into shop. All went well it just took awhile getting them all started and jockeying them around. Harry