Backhoe Backhoe Questions

[slorne]

If anyone can advise on the following, it would be great:

1) I am trying to install the backhoe on a JM254
-after installing the hydrolic lines to the pump above pto staft, I get no pressure to the backhoe
-i am assuming no pressure because nothing will work on the backhoe hydrolics
-the backhoe hydrolics were working before I removed and reinstalled the lines

2) there are two engage / dis enguage levers on my tractor (which one is for what???)
-the short one lower one - goes into gear when engaged (assuming the pto / hydrolic pump)
- the taller one pushes a screw into the housing
-the taller one seems loose

Any help would be appreciated


Thanks

 

[Harrygoodwrench]

Maybe you don't have the PTO shaft turning. There are several levers. There are 2 used for the PTO, one is on the rear of the tractor and usually has markings on it for the speed you desire. Its is a 3 position(540 RPM, neutral, and 1000 RPM) You want that in 540 RPM. now there is a short lever besides the right side(facing forward as in sitting in seat) of the drivers seat down by your right heel would be. This is the PTO engage/disengage lever, it should be engaged(depress clutch to prevent gear grinding). Try that and see what you get.
The long lever that pushes in a "screw" that you mentioned is the differential lock lever. Never mind that for now just lets get the back hoe working first. Let us know what the results are.
Harry

 

[slorne]

Harry,

I thought mabey the hydrolic fluid tank was too low as I was trying to assemble the backhoe to the tractor. (the tank was lower than the pump) - but I raised it so now it's higher.

However, now have the backhoe bolted to the tractor and still no hydrolic action from the backhoe?

I am puzzled and since everything was working before while I was positioning the backhoe before bolting it on, it seems strange..

The enguage pto goes into position and I can feel the teeth grab as I engage the pto. But still nothing from the backhoe controls.

The only thing I can figure is:

1) Air in the line??

2) The hydrolic pump is bad?? - this seems less likely but mabey??

Any suggestions??

Thanks

 

[bluechip]

In order for the backhoe pump to be pumping, the "main" PTO engage-disengage lever must be engaged (this is the one by your right heal) but eh 540-n-1000 does not need to be engaged, the pump is driven off the input side of the 2 speed PTO gearbox.

The rear pump uses oil from the backhoe hyd. oil tank, check the filter maybe? if the pressure relief valve in the hoe is stuck open, nothing works.

 

[slorne]

Bluechip,

Where is the pressure relief valve?? I think that might be the issue??

Thanks

 

[bluechip]

It is in the first (last?) block in the valve bank. Be careful not to lose the adjustment settings, just take it apart, clean and reassemble. Someone recently posted that they dissassembled and cleaned all the valves, that should not be necessary as the only place I am aware of that can cause a complete loss of working pressure is the PR valve, the oil just goes to the hoe and back to the return line.

 

[slorne]

I completed the following actions and still, no backhoe pressure / control activity:

1. Drained and replaced fluid

2. Removed what I think was a Pressure release valve
-it was a black screw cap with adjuster screw
- inside the cap was a 1 inch pointed piece of metal with a rubber washer groved into the lower portion of shaft
- I cleaned (really nothing on the pin) and replaced

3. I removed the right hydrolic line from the pump (when sitting in the seat facing steering wheel - the right side)
a. i think this is the line which sends pressure to the backhoe controls
b. When I enguaged the PTO, and let out the clutch, hydrolic fluid shot out of the hydrolic pump fitting (I think this means the pump is working)

I really dont know what to try next. Sure hate to buy another pump as they are expensive. Any suggestions would be great.

I think mabey tonight I will remove the hydrolic pump and check to see if anything looks damaged, etc..

Also, I did not see a filter for the hydrolic tank.

Thanks

 

[schmalts]

This may realy sound dumb but i think it should be covered since it seems like you are new to these tractors.
First, are you always checking to see if the hoe moves when you are in the drivers seat? reason i ask is because most guys instinctivly hold in the clutch when in the drivers seat and you will not get any hoe movement. Make sure the clutch is not pressed!!
Second, look in the tank with a flashlite. You should see the fluid moving around. any swirl or rolling of the fluid tells you the pump is fine. check these things out.
The reason i brinng up the first item is... well.... been there, done that. messed around bleeding lines all because i was always pushing in the clutch.

 

[slorne]

Schmalts,

I have checked to make sure pto is enguaged, clutch out, and tried pto speed lever in 540 / N / 1000, and still nothing.

I will now check the tank with flashlight. There only two things I can think might be the problem

1) when installing the backhoe frame mount the backhoe hydrolic tank was origionally lower then the pump
a. mabey it forced air in the lines?

2) When I disconnected the hydrolic pump lines to manuver the tractor into position for bolting backhoe frame to tractor (mabey I had the pump enguaged??)

I let you know if I see fluid moving in the tank. Thank you for the feedback. This site has been invaluable as I have assembled the tractor with out directions.

 

[slorne]

Schmalts,

I am getting a very good circulating flow inside the hydraulic tank. If your sitting on the backhoe, the flow appears to be from left to right.

However, still no hydraulic activity when moving the control levers. This one has me stumped... Any ideas??

Thanks Again