MF 290 Loader Problem

[Farmer996]

Forgive me if my terminology isn't correct but the tipping part creeps down under load. It always did it a little bit under heavy loads such as a bale of haylage but it was easy enough to manage. I was moving a pile of muck the other day and it was going fine up to a point then it started creeping down on every load, even small ones. I had to keep lifting it every couple of seconds. The oil was just above min so I topped it up to max but it made no difference.

There are no major leaks and the main lifter is fine, even with a heavy load on it. I'm guessing it's the ram but is there anything else to check? If it is the ram, how easy are they to strip down/re-build and what part(s) do I replace? Here's a pic of the ram:

Any advice appreciated. Thanks.

 

[agrimax]

Could be the ram seals or the spool valve leaking by. Set the loader on the ground and remove the pipes and get two blanking plugs to put on instead of the pipes. Lift a load and see what happens. If it still drops,the seals are leaking and if not,the spool valve is letting by.(It will drop a little to allow for the oil that escapes when you remove the pipes)
Likely better to take the ram to a hydraulics shop as,depending on the seal type,they can be difficult to refit. Some types need a resizer tool to reinstall,others are just like a rubber donut and can be easily stretched onto the piston and will contract themselves. Depends what's in there.

 

[Farmer996]

Could be the ram seals or the spool valve leaking by. Set the loader on the ground and remove the pipes and get two blanking plugs to put on instead of the pipes. Lift a load and see what happens. If it still drops,the seals are leaking and if not,the spool valve is letting by.(It will drop a little to allow for the oil that escapes when you remove the pipes)
Likely better to take the ram to a hydraulics shop as,depending on the seal type,they can be difficult to refit. Some types need a resizer tool to reinstall,others are just like a rubber donut and can be easily stretched onto the piston and will contract themselves. Depends what's in there.

Forgive my ignorance but what's a spool valve? I guess if I don't know that then I should be heading for the hydraulics shop. I used to be a motorbike mechanic and I've sorted a few tractor problems but my workshop and tools are a bit limited/dated - like me! As long as I know it's the ram, that's a start. Thanks.

 

[REStracTORATION]

Could be the ram seals or the spool valve leaking by. Set the loader on the ground and remove the pipes and get two blanking plugs to put on instead of the pipes. Lift a load and see what happens. If it still drops,the seals are leaking and if not,the spool valve is letting by.(It will drop a little to allow for the oil that escapes when you remove the pipes)
Likely better to take the ram to a hydraulics shop as,depending on the seal type,they can be difficult to refit. Some types need a resizer tool to reinstall,others are just like a rubber donut and can be easily stretched onto the piston and will contract themselves. Depends what's in there.

Good advice and perfect ideas for narrowing the issue down

 

[REStracTORATION]

Forgive my ignorance but what's a spool valve? I guess if I don't know that then I should be heading for the hydraulics shop. I used to be a motorbike mechanic and I've sorted a few tractor problems but my workshop and tools are a bit limited/dated - like me! As long as I know it's the ram, that's a start. Thanks.

Spool valve is what the levers Are attracted to that you use to operate loader
It's a valve block with a few pipes on

 

[Farmer996]

Spool valve is what the levers Are attracted to that you use to operate loader
It's a valve block with a few pipes on

Ah. I thought it was inside the ram. I checked that for leaks. I'll do what @agrimax said in case it's that. Sounds like an easier fix than the ram?

 

[agrimax]

You'll find the ram easier to fix than the valve! If the tractor has standard issue spool valves, they will likely be made by Kontak and I don't know that there are o rings in the actual spool rods themselves. Usually an interference fit. If the valve block is made up of slices, there will be o rings between them but they would leak externally and you would see the oil. More likely the ram needs fixed. Two pipes off and two pins out and take it to a repair shop.

 

[Farmer996]

You'll find the ram easier to fix than the valve! If the tractor has standard issue spool valves, they will likely be made by Kontak and I don't know that there are o rings in the actual spool rods themselves. Usually an interference fit. If the valve block is made up of slices, there will be o rings between them but they would leak externally and you would see the oil. More likely the ram needs fixed. Two pipes off and two pins out and take it to a repair shop.

Thanks very much. I'll check it out tomorrow. In terms of blanking plugs, I guess i can use a couple of bolts (correct thread of course) with copper/alloy/fibre washers?

 

[REStracTORATION]

Ah. I thought it was inside the ram. I checked that for leaks. I'll do what @agrimax said in case it's that. Sounds like an easier fix than the ram?

It's the best place to start is the ram always check out the simples 1st to many people rush in without a correct diagnosis

Best of luck keep up. Informed of your findings

 

[REStracTORATION]

Thanks very much. I'll check it out tomorrow. In terms of blanking plugs, I guess i can use a couple of bolts (correct thread of course) with copper/alloy/fibre washers?

They will be half inch or 3/8 fitting
So just screw some couplers on to blank off

 

[Farmer996]

They will be half inch or 3/8 fitting
So just screw some couplers on to blank off

Couplers? I really am an amateur tractor mechanic. But you've got to try given how much the so-called professionals charge. Or at least do as much as you can yourself.

 

[REStracTORATION]

Couplers? I really am an amateur tractor mechanic. But you've got to try given how much the so-called professionals charge. Or at least do as much as you can yourself.

Sorry
Couplers are the quick release fitting that your tipping pipe has on the end they should fit the ram to blank it

 

[Pennine Ploughing]

looking at the picture, the rams seem to be single acting, as there is no enough pipes,
if the lift ram as only 1 pipe to it, then for the ram ( they dont internally ) to leak it would be easy to see as the oil would externally leak on to the ground, if the ram has 2 pipes to each ram, then it could be an internal leak

as for the spool valve, the O rings only seal slice to slice, there would be a big oil leak if 1 of the O ring has gone, does it look very oilly and leaking from the spool valve, this will be near the handle under the cab?

never seen a worn spool valve in my time, must of been lucky, but i doubt it is worn,

most likely answer if no leaks and i single acting ram ( 1pipe to it only )
is a weak centralizing spring on spool shaft, does the lever feel good and tight, or does it have some free movement on it ?

 

[Pennine Ploughing]

Sorry
Couplers are the quick release fitting that your tipping pipe has on the end they should fit the ram to blank it

Rams will be 3/8 bsp, and couplers will be 1/2 bsp as far as i remember

 

[REStracTORATION]

Rams will be 3/8 bsp, and couplers will be 1/2 bsp as far as i remember

Yea I said 3/8s before I think
I was using the tipping pipe as a reference to a coupler so he knew what I meant that's all

 

[Pennine Ploughing]

Yea I said 3/8s before I think
I was using the tipping pipe as a reference to a coupler so he knew what I meant that's all

yes but single acting rams cannot leak internally, if they where leaking he would see it

 

[REStracTORATION]

yes but single acting rams cannot leak internally, if they where leaking he would see it

I thought the pic was the crowd ram

Note to self I must pay more attention

 

[Pennine Ploughing]

I thought the pic was the crowd ram

Note to self I must pay more attention

no your right is me that should pay more attention its been a long week,,

you right i read the op again,

yes check the ram first, as it can leak internally











I am off form a lie down in a darkend room

 

[Farmer996]

@Pennine Ploughing. There are 2 pipes to the tipping ram and 1 to each lifting ram. Lever feels OK.

@REStracTORATION. I guess you mean these couplers to use as blanking plugs? I don't have any spares but I'm sure I'll find something to fit. Got loads of tubs of old bolts.

Thanks to all.

 

[REStracTORATION]

@Pennine Ploughing. There are 2 pipes to the tipping ram and 1 to each lifting ram. Lever feels OK.

@REStracTORATION. I guess you mean these couplers to use as blanking plugs? I don't have any spares but I'm sure I'll find something to fit. Got loads of tubs of old bolts.

Thanks to all.

View attachment 570288

Yes that them can you remove them off other implements to try them
As these are the right thread and they are sealed for hydraulic pressure these would be best thing to use
A bolt won't fit nor will a nut