Fordson Super Major Auxilary service Block

[YCJ357-SMD]

Hello,
I was hoping some one can help me identify the cause of the problem I am having with the plug seal "O" ring problem I'm having ,
a bit of background info, for a number of years there has been a steady dribble of oil leaking around the 5 plugs in the auxiliary casing, so deciding it was time to do something about it, so purchased a plug kit from Agriline, I replaced all the plugs with the new ones and the O rings in the pack, now twice in a week whilst using a post rammer on the rear three point linkage the O ring on the plug that contains the flow control valve has blown from around plug.
we used the post rammer for many years without any problems prior to changing the plugs and seals,
when I removed the plugs from the casing I was not able to withdraw the flow control valve from the block, it would move back and forth a small distance and could be turned round inside the drilling but would not be pulled back, not sure whether this is something to do with the problem or not? one more thing to note is that the arms now only start to lift when the raise/lower lever is at very top of quadrant, I had the top off and adjusted the linkage a couple of years back and lever had been working fine since then,

hope this info helps someone to assist in diagnosing the fault
many thanks in advance for any help you can give

Regards
Stuart

[YCJ357-SMD]

Hello, The problem keeps reoccurring blown out 2 more 'O' rings over the weekend, I've tried putting the original plug back in with a new seal but still same thing happens after some use. So now going to try some thicker O rings in attempt to try and stop the same thing happening again. Not sure what else i can do?