Loader Valve Is Restricting Flow--Need advice

[RickB]

Good news! I found (per your suggestion) that loosening the end cap for the curl spool gives enough additional spool travel to nearly double the curl-in speed. Seems that one turn loose of the capscrew makes all the difference.
It has been taking about 19 seconds at low idle (1000 RPM) to curl-in but that time drops to 11 seconds at one turn loose and about 5 seconds at high idle (3000 RPM)

I now see that there is some casting flash down inside the cap. (see pic) The flash seems to be shiny indicating that the end of the spool retainer is contacting it. Will remove the flash and see if that fixes it. Otherwise can shim or remove about 1/32" to get the equivalent of half of turn on the #10-32 screws.

Will report back. Meanwhile want to thank you again for suggesting to check the end cap!!!!!

You are very welcome!

 

[oldnslo]

I will pull my valve apart tomorrow and see what the spring compression is. 1/2 doesn稚 sound right.

 

[npalen]

There is a second spring assembly that resides just under the outer cap and is apparently for the regen position. Its a preloaded assembly that contains detent balls. The bolt that preloads the long spool spring contains a groove in its head that engages balls in the preloaded assembly and acts as a bit of detent for the regen position.
Its a bit complicated from what I'm used to seeing under a spool cap.

 

[npalen]

I made a 0.040" shim, shows as yellow in the attached photo, to move the spool outer cover out allowing the additional spool travel. This nearly doubled the speed of the curl-in function from 19 seconds to 11 seconds at low idle. The speed is improved to 4-5 seconds at high idle (3000 RPM) which is reasonable considering 2" bore x 1" rod x 21" stroke.

The spring assembly in the photo is for the regen function and provides the tactile feedback when going from normal dump to regen dump position. There are four small balls barely visible that act as a definite feel of going into regen when shifting the valve handle all the way to the right. This assembly is normally free floating until the spool moves the other direction from curl-in.

The 0.040" mentioned sure shows the sensitivity of these small valves and how a stackup of tolerances within the valve/spool assembly can result in issues. Even a permanent mold gray iron casting is hard pressed to maintain dimensions in thousandths of an inch.

Again, thanks guys for the feedback in this thread which gave me the incentive to move forward and check things out. Happy camper now!

 

[oldnslo]

npalen,
Glad that you have it working to your satisfaction.

Silly question but if you put a load in the bucket or have forks can you feather the tilt function? Reason I ask is the total inability to feather a load was the reason I removed the Nimco valve from my tractor. It had zero feathering while lowering the loader and on the tilt function.

 

[npalen]

Yes, the bucket can be feathered when dumping the load. This area of the spool acts just like a valve without regen.
Makes we wonder if there is a bad or non existent load check in the Nimco valve.
Does the Nimco happen to have P and T ports in the end rather than top or sides? That might make a good backup for mine.

 

[oldnslo]

Npalen,
I do not believe it was a load check problem since while trying to raise or curl a load it did not drop. Lowering a load was the problem. I looked at the valve but did not remove the extra P & T plugs in the end of the to confirm they connect to the ones on top but 99% certain they do. Attached pictures is an attempt to show the end ports.

 

[Dave M7040]

Npalen,
I looked and the Nimco valve that I have is 12455-2S CV112. The curl spool travel is approximately 3/8" total or 3/16" each way from center. When I purchased my tractor with this valve the joy stick knuckle assembly was a ball of rust that I have to work free.

Nimco says you have a load check on each spool with a CV112

Two spool compact special loader valve with built in load holding check valves for each spool section. Designed for minimal spool leakage less than 1cc/min and optimal load controls on small front end loaders.
Nimco
Dave M7040