185 hydraulic problem

Been having trouble with the hydraulics on my '74 185 for a while now.  I've talked with my Allis mechanic and he gave me some ideas.  It helped it but it's still not right.  When I used the rear remotes and pull the lever back to raise whatever I'm pulling sometimes it works right and sometimes it kicks out the relief valve.  I checked the pressures and they are right, put new hose ends on the tractor, and even put a different relief valve on it.  The different valve helped for a while but it got to the point last fall that I could even lift my haybine.  I changed the filter and pulled the relief valve, cleaned it up and put it back in.  It worked after that and it ran the loader fine all winter.  I used it on the disk a few days ago and it started acting up again.  When i would go to raise it it would kick the relief valve.  I'd center the lever and try again sometimes having to barely feather the lever back enough to get it to lift with out kicking out the relief valve.  Does anyone have any other ideas????  Sorry for the long post, I'm just about at my wits end with this thing!!!

And the valve goes in the left front corner of the valve stack pointing forwards.

Mack,

I have switched them before and switched them back a couple different times.  Some things that works on and some it doesn't as the rear relief valve opens at a lower pressure.  Thanks for the idea though!