310SG loader won’t hold the front end up.

This 310SG will raise the front end off the ground but will not hold it up. Sort of like it’s in float position. It goes back down when I let go of the lever and the loader will sometimes slowly lower itself after raising the bucket off the ground. It never holds the front end up but only occasionally will lower itself after raising the bucket. I think it’s in the valve body but before I dive into that mess I would like some professional opinions.