644 & 646 disapointing results

[Harry]

Toady I dug a trench with my 644lbh about 30" long. It worked incredubly well during the trenching operation and I'm glad I rebuilt the hoe cylinders over the winter. I then moved some dirt in a low spot of the garden to back fill with the trenched dirt, then pull the original dirt over the top. After removing the dirt it was a bit wet underneath and because of the low to the ground counter weights it kept getting stuck.

I parked it and returned with the 646 with more ground clearance to stop the getting stuck situation. I would scoop up a bucket full of dirt that was removed from the trench. Then move into the low area to to dump it. It also would get stuck in the low area. The tires would sink into the mud and the pressure relief would squeal and just sit there. I would have to dump the load and use the loader to work my way out. Very frustrating situation for me and after moving back and forth through the mud hole I finally filled up the low spot and back dragged the original dirt into the area.

The 644lbh has a hydraulic pressure gauge that a PO installed on the dashboard. Under a load the pressure relief would squeal at 1500 psi. I see according to the Case manual this should be set at 2000 +- 50 psi to 2100 =- 50 psi.

I pulled the 646 into the shop and crawled under it to look at the travel control and found it is located so close to the rear it is literally impossible to take off the cap to adjust the pressure yet alone get a screw driver in there to do it. The travel control is bolted to the floor board and the floor board is welded to the frame of the tractor. I didn't look under the 644lbh, but I imagine it is about the same situation.

May I ask how can an owner set the pressure, when it is impossible to get in there? I could cut a section of the floor board away and have it bolt back in place, but I doubt I could get a screw driver in there to adjust it. A dilemia for sure.

Keep the Peace
Harry

[Spike188]

Harry, setting the relief pressure is something I have not tried yet. Sorry I can't help you.

Spike

[JSinMO]

Harry
I’m sorry I don’t have an answer for you.

I’m really interested in what you come up with as it relates to what I may do with my 648.

[Jancoe]

If I remember correctly your travel relief should be set to 2400 +-50 psi. On the back of the frame where a 3point would be bolted to the frame. Remove the bolt and then relief cap and stick a long screwdriver something like a 14" one through the hole over top of the rear axle to the relief screw and make adjustments. Make one if you have to out of a rod if you need to.

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[Eugen]

I have a hard time thinking it's built in such way that adjusting the pressure relief valve is impossible. My logic tells me there must be a way.

[propane1]

That sure would be frustrating Harry. Hope you get it figured out. Maybe Jancoe’s idea is the trick to adjust it.

Noel

[Harry]

If I remember correctly your travel relief should be set to 2400 +-50 psi. On the back of the frame where a 3point would be bolted to the frame. Remove the bolt and then relief cap and stick a long screwdriver something like a 14" one through the hole over top of the rear axle to the relief screw and make adjustments. Make one if you have to out of a rod if you need to.

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I'm going to look at the 644lbh today Jancoe. I passing thought yesterday was maybe it was accesable from the rear, not so easy with a hoe hanging on the back. If this is possible I would still have to remove the cap and put it back on which would take a bit of magic. Thanks for your input.

Keep the Peace
Harry

[Harry]

If I remember correctly your travel relief should be set to 2400 +-50 psi. On the back of the frame where a 3point would be bolted to the frame. Remove the bolt and then relief cap and stick a long screwdriver something like a 14" one through the hole over top of the rear axle to the relief screw and make adjustments. Make one if you have to out of a rod if you need to.

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I found the pic in timely tips for the screw driver fabrication. I didn't see what magic is needed to get the relief cap off.

Keep the Peace
Harry

[Eugen]

Very useful! Thank you!

[Jancoe]

That's the bulletin I remember seeing with that reference Harry. Good luck getting it adjusted.

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