3 point and remote weak

[Donnyncarol]

Ok, hopefully someone here will know what's up with this Montana/ LG/ agracat 4740lx. New hydraulic pump, new filters. I replaced the hydraulic pump because no was running a 3pt backhoe probably 10 years ago and well.... It was way to much for this little tractor. I bought bit new as a 50 horse, wasn't until the first oil change I did on it I found out it is a 40. Anyway, the hydraulic pump kept getting weaker and weaker So I finally broke down a replaced it. Everything seemed to be working fine. Fast forward a few months, it's hay season and I put on the cutter. I have to rev the engine to 2800 RPM or more for the 3 point to lift it. When I try to raise the cutter bar with the remote same result. The load works fine with plenty of power. Also I can hear fluid passing through the hoses on the loader valve. Any thoughts? Thanks in advance

 

[Donnyncarol]

Maybe to add this is an LG cable tractor, Montana says it was made before they purchased the company, but they sell parts as a 4340, and a 4940. But the parts come from LS as a LS Neo47. Confused. Me too..

 

[ptsg]

Did you clean the strainer/screen for the hydraulic pumps on the transmission?

 

[Donnyncarol]

New filter new oil. Not aware of a screen anywhere. Thank you for the reply

 

[ptsg]

Since you mention the loader works just fine, my guess is that the lines from the loader valve that will feed the 3 pt and remotes may be messed up.

What happens if you move the lever for the 3 pt to lift, then you move the joystick of the loader till the cylinders reach the end of the stroke? If the 3 pt will then lift, then the lines are not connected right.

 

[Donnyncarol]

Ugh I tried to change a typo and the whole new explanation of what I have done got deleted. Lesson learned. Typo or not leave it alone

 

[Donnyncarol]

I have not tried that. But the plumbing is factory. But I will go out and try it. But inside not sure if I can reach full lift on the loader. But I will attempt to.

 

[ptsg]

Use the curl/dump instead of the loader lift.

 

[Donnyncarol]

Ok by making the curl go-to end of stroke I can get a pressure reading to the rear remote of 700 PSI. But it took repeatedly hitting end of stroke and it would jump about 100 PSI each time to a Max of 700 psi. When the curl was traveling it would stop the lift of the 3 point. When I released the curl it would resume to move slowly.

 

[ptsg]

I'm very suspicious of the plumbing of the tractor hydraulic system but without a hydraulic diagram, it's very hard to give valid advice.

 

[Donnyncarol]

The plumbing is from the factory. None of which has been changed. I bought the tractor new from dealer. I do not have a diagram either even with the "service manual" that LS put out. It is very non specific. I can tell you the pump pumps to the diverter block, with a pressure relief valve there. On the right (looking at diverter block ) of the block the loader hooks to it with 3 lines. One on the passenger side of the tractor there is a hard line that goes to the steering. The left side of the block 2 hard lines, one that supplies the rear remote and 3 point. The other is to the filter. On the front the relief valve and the spool plug *. With the o-ring.

 

[Donnyncarol]

. This is what is in my manual. It is very close but not completely accurate. I believe the power steering is a little different

 

[Donnyncarol]

It also doesn't show the diverter block. Just noticed that.

 

[ptsg]

Do you have any info on this diverter block or pictures? It might have a spool that you would switch to allow the flow to go to the 3 pt and remotes.

 

[Tx Jim]

My WAG is the 3 pt relief valve isn't seating properly.

 

[Donnyncarol]

. The plug #3 is set above the pressure relief valve and where it is shown is the FEL connections.

 

[Donnyncarol]

My WAG is the 3 pt relief valve isn't seating properly.

If you are speaking of the pressure relief valve on the side of the 3 point cylinder casing. I thought the same as well. I have no way of testing this relief valve. But the copper washer under it has been replaced. The one that came out of it from the factory looked as if they punched it into the hole. And was malformed. But it did work this way since 2003

 

[Donnyncarol]

. #10 is the pressure relief valve to the 3 point. I have replaced the copper washer that goes behind it. As for the relief valve itself. I have no way of testing it. Is this the relief valve to are speaking of?

 

[ptsg]

View attachment 629388. #10 is the pressure relief valve to the 3 point. I have replaced the copper washer that goes behind it. As for the relief valve itself. I have no way of testing it. Is this the relief valve to are speaking of?

That looks like the safety relief valve for the 3 pt. Like, if you have a heavy implement on the 3pt, you then happen to drive fast over an aggressive bump, that relief will let go to relieve the shock load. So it wont, either break stuff or blow the seals of the piston. That's why there is no way to adjust it.

 

[Donnyncarol]

Yeah I a sure that's what it is. I was asking Tx Jim if that was the relief valve he was speaking of.