Thx Kerry. Here's the thing, I've got a buzzing noise that changes exactly with my RPMs. I know there could be many other things that cause this, but I've narrowed it down.

With the car running, I can put my hands on the metal tubing that runs along the passenger side under the car and feel the vibration. If I go in the back, the noise is clearly coming from right where the hydro shocks are and the metal tubing that runs under there. I can hear it in the car and under the car. It actually changes pitch when going over bumps at speed when the suspension is compressed and released.

I bought a rebuild kit for the pump that seals everything that can be sealed, o-ringed or gasketed (made up word). I re-sealed the valve in the back, twice. I replaced both hydro shocks and all the rubber on the rear subframe, mounts (3) , trans mount and motor mounts. I've traced the exhaust to see if its touching anything, I've traced the SLS lines to make sure that the rubber bushings aren't disintegrating and touching and I've run out of things to look for.

I spoke with someone I know that is extremely knowledgeable about my plight and he said that it sounds like a cavitation problem, which leads me full circle to why I took it apart in the first place.

Maybe it is the shape of the old hose? I could just get a new hose and see if it changes. It could also just be a burn pump due to running dry before I bought the car, but it does level the car fine and I didn't notice anything when I had it open and pushed the pistons to see if they moved freely.

The suspension works properly when driving, not bumpy, and it fills properly. Just that buzzing/vibration noise all the time.

I am way open to suggestion, but when I previously posted this nobody really had the problem so they couldn't help.

Sorry for the short story turned long, but the plastic pieces were just the next step. I would love for someone to step up and tell me how they fixed this without replacing a $1000 pump.

Thanks to all that have pitched in on suggestions already.

Todd

__________________
1980 300TD, SOLD
1984 300TD, 275K
1999 C230 K Black & Tan
2013 C250 Black
1974 CJ5 Red
You might faint from the fight, but you're gonna find it. Every challenge could have paradise behind it. -John Popper-