Ok, I'm never surprised when our Meyer plows angle to the left when you ask them to go right, or up. In fact the first thing I do when I start the truck is to angle the blade right. If it isn't going to behave properly I want to know before I get it all pumped full of pressure and angled all the way to the left.
Today's malady is a new one on me though--The blade goes up and down just fine. When asked to angle right, it does so with no problem. When asked to angle left though, it might jerk just a little bit in that direction, but won't go any further. If you push on the extereme left end of the blade (and it doesn't have to be very hard--a pile of heavy wet snow would do the trick), it *will* angle left. At one point, I was able to pull the blade either left or right by hand, although later I couldn't. It started acting this way after bumping a curb with the left end of the blade. Fluid level is good, and the quick disconnects seemed to be ok too (although this is based on simply uncoupling and recoupling them).
I have a suspicion about what it might be, but I won't pollute the pool of Meyer wisdom available here with my speculations.
I had this problem last week on my stepfather's truck with a ST-7.5 and an E60. It turned out the crossover relief valve had somehow worked it's way loose so while the pump was running, not enough pressure was builing up to angle the blade. I just had to adjust it. Pretty simple procedure, but you need a 5000 PSI Guage and an immobile object. The instructions are in the service manual that you can get here...