460 hydraulics

[GSRFord]

I need some help on a relatives 460. When he tries to start it the hydraulic pump seems to be dragging the starter down. You can get it started if you pull the lever to raise the loader.Once running it still seems to be laboring against the pump. I was told the hydraulic controls and pump are factory units. Seems to be loading up against something when the control lever is in the neutral position. Where to start looking? Thanks

 

[Janicholson]

The system is not open center like older systems. It is also not a closed system as in new high pressure tractors. It is a pilot controlled system with an unloading valve that dumps almost all hydraulic pressure until a valve is opened. When that happens, a pilot orifice ans small screen detect the pressure change, and open up, allowing full pump pressure to go to the valve, and thus, the implement or connected hydraulics.
The screen is probably plugged up, or the orifice has a particle in it causing the system to be on demand all the time. The pilot and screen are in the first valve in the stack of valves. It is a regulator. caseih.com search for parts (diagrams) Jim

 

[GSRFord]

Jim, thanks for the explanation. That makes sense, but I am not sure what I'm looking for on the parts website. I have been looking at the page showing the handles and valve banks. Which valve would you call the 1st one? Also I don't see any screen shown anywhere in the valves. Would this not be shown and be considered serviced only with the valve? Maybe I'm not looking at the right page either.Thanks

 

[pete 23]

The regulating valve is separate from other valves and is the one with four bolts on the cover. No handles or linkages.

 

[GSRFord]

Pete, I think I am on the right page in the parts manual now. I see the breakdown of the regulating and safety valve. Jim mentioned a small orifice and a screen that might be plugged. I don't see any screen. Do I just need to disassemble the valve and clean it out? Thanks

 

[the tractor vet]

Yep , ya need to clean the valve and screen and make sure that the valve piston floats free . Next ya need to change the hyd.filter and oil. She is sucking junk from somewhere and sticking the valve. I had a 460 one time that ate a rear axle bearing and contaminated the hyd. oil We changed the bearing and flushed the system SO we thought installed new filter and new oil . Thinking that it was good to go , WRONG even with new filter new oil my probelms were just getting started . It would still get fines past the fliter and stick the reg. valve and plum put the fire out and stall the tractor . Between changing the hyd. filters and working on that valve it is a wonder that there were any threads left in the bolt holes. We went thru a 55 gallon drum of Hy Tran and i don't remember how many five gallon buckets and four cases of filters and numerous system flushing with diesel fuel and steam cleaning before the problem was cured. So clean the valve and screen look for nicks and scratches inside the and on the outside of the valve and polish up with varyfine emery cloth change filters and oil and see if this cures your problem .

 

[pete 23]

The screen is on the orfice which is a screwdriver slotted screw right between relief valve and regulator valve. You will easily see it when you get the cover off. Use a couple of longer bolts when taking cover off as the relief valve spring is very strong. If you have metal contamination like the Vet is talking about, you can plug the bypass screen on filter so all oil has to go through paper element. We always did that after a power train failure and did a cleanup procedure. After a couple hours of running using all valves we put new filter in along with the regular screen bypass valve. The larger tractors had a special fine filter for cleanup purposes but I don't remember the 460 style ever having one. But, there were three different kind of filters used on a 460. Original one was just a screen, next one was screen with do-nut filters inside of screen and then the latest was paper with screen bypass.

 

[GSRFord]

Thanks to everyone for your input. It will be a while before I get to it , but I will check it out.

 

[Anonymous-0]

You need to check your regulator & safety valve under the dash, the parts you will need a at minimum are gasket 360630R1, oring 352024R1, orifice & screen 370766R92. You will probably have to get these from CNH.