Opinion on check valve in loader control valve

[Tmod]

Ok had my tractor at the dealer for a check valve upgrade and now that I got it back and if I feather the joytick to curl the bucket up it will completely fall.

After talking to them they say there was not a spring in the check valve but I am thinking there was and it popped out or just rolled away.

Anyway there are no diagrams of the internal components of the loader control valve so I am not able to verify there was originally a spring in there to begin with but IMO there had to have been.

Take a look at the following images and offer up your thoughts on whether there was a spring in there or not, The internal base is machined flat so a spring would sit nice and flat in there.

 

[oldnslo]

My answer is yes there should be a spring to keep the check poppet in closed position

Are there two checks in this valve or just one? Most valves have load checks on each spool so if two check the other one.

 

[RickB]

My answer is yes there should be a spring to keep the check poppet in closed position

Are there two checks in this valve or just one? Most valves have load checks on each spool so if two check the other one.

Agreed.

 

[Tmod]

Only the one check and on the opposite side there is the pressure relief valve and of course the spools to the sides.

 

[oldnslo]

Does the loader drop when trying to raise slowly? If not then the check is working for that section.

If you curl it back fully does it stay curled?

When curled back can you feather the dump?

 

[Tmod]

Does the loader drop when trying to raise slowly? If not then the check is working for that section.

If you curl it back fully does it stay curled?

When curled back can you feather the dump?

The loader itself will raise and lower both very smoothly and when feathering there is no drop whatsoever. Well the loader will drop quickly when raised all the way but if you really feather the stick it will go down slowly.

As far as I can tell through my testing once curled the bucket will stay.

Interesting thing is if I do a quick left stick then the bucket will curl after a short drop.

Yes I can feather the dump and it will act normal on that.

Flow diagram of loader control valve.

 

[oldnslo]

Since there is only one load check the oil can flow freely between the two functions so if trying to lower & curl the bucket could dump since it takes less pressure to lower so oil could flow from curl to lower.

Same with raise and dump. Loader will drop if trying to raise and dump at the same time.

I had a valve like this and replaced it for those reasons

 

[Tmod]

Since there is only one load check the oil can flow freely between the two functions so if trying to lower & curl the bucket could dump since it takes less pressure to lower so oil could flow from curl to lower.

Same with raise and dump. Loader will drop if trying to raise and dump at the same time.

I had a valve like this and replaced it for those reasons

Yeah as far as performing two functions at the same time forget about it with this setup.

I still think they left the spring out of the check as never had this issue prior. Not running the boom when the bucket falls even though it is supposed to be curling up.