deere 575

[oaktree0]

i recently brought my 575 in the shop and towards the end of parking it.it lost all its hydraulic pressure. so i checked the fluid and it was milky and full of water from being outside. i drained the fluid,changed filters and cleaned the mesh tube that filters the fluid.did the whole process again to get the remaining water/milky oil out. no i have no hydraulic movement in the bucket or forward or reverse. can anyone give me some idea where else to start checking. i took the one filter off and turned the machine on and the fluid comes out like crazy still so i know some pump is still working.help?

 

[Tazza]

Does it try and move? does the engine bog down when you try and lift/tilt or move?
Just wondering if it's a safety interlock issue or not.

 

[oaktree0]

Does it try and move? does the engine bog down when you try and lift/tilt or move?
Just wondering if it's a safety interlock issue or not.

no sir the engine does bog or change rpms.what is the safety interlock?

 

[jerry]

no sir the engine does bog or change rpms.what is the safety interlock?

Try posting this in the New Holland section, I think one of that age was made by New Holland and Mike10 may have answers for you.

 

[oaktree0]

Try posting this in the New Holland section, I think one of that age was made by New Holland and Mike10 may have answers for you.

ok will try thanks

 

[Tazza]

ok will try thanks

How about i move this thread to the NH section

 

[Mike10]

Since you have no hydraulic and no hydrostat functions the likely place to start looking is the hydraulic pump. The hydraulic pump is at the front of the hydrostat pumps. The hose from the standpipe screen you cleaned is attached to one end of the pump.
Remove the kick panels so you can access the pump. Remove the two hoses and the pump is bolted to the hydro pump with two bolts. Remove these two bolts and the pump can be removed.
Things to check once the pump is out.
1) Check that the hydraulic pump shaft is not broken off.
2) Crank the engine over while watching the hydrostat shaft the hydraulic pump splines into. If it turns the problem is in the hydraulic pump. If the hydro pump shaft does not turn then the connection between the engine and the hydrostat has failed. On the NH machines there is a flex plate attached to the flywheel that drives the hydro pumps. The splines can strip out or the rivets attaching the center hub to the flex plate can fail.
3) If the hydro pump shaft turns then you will need to disassemble the hydraulic pump and check for damage. If none is found then resealing the pump should get you back in service. Be sure to mark the pump before disassembly so you don't get the center section installed backwards. It is normal to see where the gears have rubbed the he center section on the suction side. Check the bushing the gear shafts run in for excessive wear.
Since your loader quit while you were operating it I would suspect item 2 to be your problem.

 

[oaktree0]

Since you have no hydraulic and no hydrostat functions the likely place to start looking is the hydraulic pump. The hydraulic pump is at the front of the hydrostat pumps. The hose from the standpipe screen you cleaned is attached to one end of the pump.
Remove the kick panels so you can access the pump. Remove the two hoses and the pump is bolted to the hydro pump with two bolts. Remove these two bolts and the pump can be removed.
Things to check once the pump is out.
1) Check that the hydraulic pump shaft is not broken off.
2) Crank the engine over while watching the hydrostat shaft the hydraulic pump splines into. If it turns the problem is in the hydraulic pump. If the hydro pump shaft does not turn then the connection between the engine and the hydrostat has failed. On the NH machines there is a flex plate attached to the flywheel that drives the hydro pumps. The splines can strip out or the rivets attaching the center hub to the flex plate can fail.
3) If the hydro pump shaft turns then you will need to disassemble the hydraulic pump and check for damage. If none is found then resealing the pump should get you back in service. Be sure to mark the pump before disassembly so you don't get the center section installed backwards. It is normal to see where the gears have rubbed the he center section on the suction side. Check the bushing the gear shafts run in for excessive wear.
Since your loader quit while you were operating it I would suspect item 2 to be your problem.

when i take the one filter off the fluid is gushen out under pressure. doesnt that mean the pump is still workin or no?

 

[jerry]

when i take the one filter off the fluid is gushen out under pressure. doesnt that mean the pump is still workin or no?

That may or may not tell you anything, if the drive to the pump is broken it may still operate enough to move oil when there is no restriction such as if you take a hose or filter off. Best to chase it down like Mike said.

 

[jerry]

That may or may not tell you anything, if the drive to the pump is broken it may still operate enough to move oil when there is no restriction such as if you take a hose or filter off. Best to chase it down like Mike said.

If you have aux hydraulic connectors plug a gauge into one and that will tell you if you have pump pressure also.

 

[Mike10]

when i take the one filter off the fluid is gushen out under pressure. doesnt that mean the pump is still workin or no?

The pump may be working to a certain extent but can not build enough pressure for anything to work. I can not remember what the check valve is set at for the hydrostat to funcion but I think it is about 60 lbs. PSI. If the pump was putting out at least 60 PSI the unit would move. It also must put out enough pressure to overcome the weight of the boom or bucket. 60 PSI would not do that. Does your charge pressure warning light work and does it go out when the engine is running?

 

[oaktree0]

The pump may be working to a certain extent but can not build enough pressure for anything to work. I can not remember what the check valve is set at for the hydrostat to funcion but I think it is about 60 lbs. PSI. If the pump was putting out at least 60 PSI the unit would move. It also must put out enough pressure to overcome the weight of the boom or bucket. 60 PSI would not do that. Does your charge pressure warning light work and does it go out when the engine is running?

ok boys got the hydraulic pump off and the gasket inside the pump which is odd looking is all in pieces. this gasket goes into small slots and has 1 separate 1inch slot. would this be the problem? the spline on the hydro shaft still spins nicely.

 

[Mike10]

ok boys got the hydraulic pump off and the gasket inside the pump which is odd looking is all in pieces. this gasket goes into small slots and has 1 separate 1inch slot. would this be the problem? the spline on the hydro shaft still spins nicely.

You found your problem. The seals in the pump are used to keep the floating endplate tight against the gears. If the floating plate is not pushed up against the gears the oil will just leak out around the gears and not build pressure in the hysraulic system.

 

[oaktree0]

You found your problem. The seals in the pump are used to keep the floating endplate tight against the gears. If the floating plate is not pushed up against the gears the oil will just leak out around the gears and not build pressure in the hysraulic system.

its been awhile before i could get gaskets and fix but i installed today and still have no fluid pressure? any ideas

 

[Mike10]

its been awhile before i could get gaskets and fix but i installed today and still have no fluid pressure? any ideas

There is a screen in a standpipe on the suction side of the pump. Have you removed it to see if it is plugged. The pipe is at the other end of the larger hose which connects to the pump. You will need to remove the small kick plate next to the one you removed to get to the pump. If it is clean you might try overfilling the hydraulic reservoir. An extra couple of gallons of oil will not harm anything.
Did you mark your pump before disassembly to make sure you did not install the center section backwards on reassembly?

 

[oaktree0]

There is a screen in a standpipe on the suction side of the pump. Have you removed it to see if it is plugged. The pipe is at the other end of the larger hose which connects to the pump. You will need to remove the small kick plate next to the one you removed to get to the pump. If it is clean you might try overfilling the hydraulic reservoir. An extra couple of gallons of oil will not harm anything.
Did you mark your pump before disassembly to make sure you did not install the center section backwards on reassembly?

yes i marked the pump and it was installed correctly. is the sand tube your talking about 8 inches long? i did remove and cleaned the fine mesh filter already before i started this project.i am at a stand still. there is just no fluid movement. maybe there is a bleeder or something else plugged up.im about to give up. cant even move it to have someone look at it.

 

[Mike10]

yes i marked the pump and it was installed correctly. is the sand tube your talking about 8 inches long? i did remove and cleaned the fine mesh filter already before i started this project.i am at a stand still. there is just no fluid movement. maybe there is a bleeder or something else plugged up.im about to give up. cant even move it to have someone look at it.

I would first remove the cap from the stand pipe where the screen is and see if the oil is up in the pipe. It is possible something might be blocking the hole at the bottom of the standpipe.
If you had a flow meter I would connect it to the pressure side of the pump and see if you indeed have flow from the pump and if the pump can build pressure. If you are careful you can do the same thing by connecting a hose to the pressure side of the pump with a pressure gauge tee'd into the hose and a hyd gate valve. You can run the other end of the hose into the dipstick tube. If you have flow then slowly close the gate valve while watching the pressure gauge being careful not to totally close the valve or build pressure above 2500 PSI. If you can build at least 1000 PSI then you should have some action from the controls when reconnected. If you have flow until the gate valve is closing then you have a pump problem.
Try not to run the engine any more than necessary since the hydros are not being supplied oil.

 

[Mike10]

I would first remove the cap from the stand pipe where the screen is and see if the oil is up in the pipe. It is possible something might be blocking the hole at the bottom of the standpipe.
If you had a flow meter I would connect it to the pressure side of the pump and see if you indeed have flow from the pump and if the pump can build pressure. If you are careful you can do the same thing by connecting a hose to the pressure side of the pump with a pressure gauge tee'd into the hose and a hyd gate valve. You can run the other end of the hose into the dipstick tube. If you have flow then slowly close the gate valve while watching the pressure gauge being careful not to totally close the valve or build pressure above 2500 PSI. If you can build at least 1000 PSI then you should have some action from the controls when reconnected. If you have flow until the gate valve is closing then you have a pump problem.
Try not to run the engine any more than necessary since the hydros are not being supplied oil.

After thinking about the way I told you to check the pump I think it would be best to just use a flow meter. If you do not have access to the hydraulic gate valve you would not be able to test safely.