cat 303.5 engine, hydrolics

2 part question. 1, just bought it, engine is 3 cyl perkins. It vibrates, mostly when just above idle, but powers up and seems ok. I thought maybe injector? Anyone know how to isolate the ofender if that might be it? 2; boom swing does not work in ether direction. (body swing is ok). Also, anyone know how to get into the hydraulic connector bank? I also have a 303.5c cr which has a lift up door which houses the hydr bank and tank. I am new to these machines, altho have worked on other simular equipment. Thanks for replys, Charlie

cat 303.5 engine, hydrolics