Question about a White 2-85

Jeff picked up a real nice White 2-85 this winter, but it's having some hydraulic problems. It seems like it's putting out too much pressure, and has a vibration in the remotes if you don't move the lever all the way. The couplers are worn some and Jeff is going to replace them today, but it will shake the couplers so hard that the hoses will pop out. must have reattached those hoses 20 times yesterday before I figured out why it was happening. Once they pop out there is a tremendous amount of pressure on the hoses, way more than I've seen from other tractors. So my questions are, what would cause that vibration, and is there a pressure relief valve that we can get too to see if it's been cranked down too tight?

Real easy to adjust. I made up a tester using a pioner male end, reducer, 6 inch nipple, 1/4 inch coupler and and old airco oxygen regulator gauge.
The adjustment is on outside of the hydraulic pump. It is on the upper front part of the pump.
There maybe a wire twist lock on it Use a big screw driver to turn it out for less pressure. If it has not been touched for a long time you may have to use a torch to help it along.
Also, have had some foreign material get in it.
If you have to take it off(4 sllen bolts, make sure you have an extra gasket and 2 little orings
that go between the valve and pump. The gasket is paper thin and almost always tears.
If this does not help, there is a wealth of knowledge on the Oliver board.
I still have a few Whites left with more than 10 to 12,000 hours. Bought my first one in 1976. They have been good tractors and fairly economical to keep running.
I have never blown out a coupler. Pioneer uses 2 or three styles. Maybe you have a mismatch. I take that back I had one fall off and it rubbed part of ball off on road pavement.
ps If You need any parts and can not find them anywhere else, shoot me an email. I still could spare a few.