4200xl old problems

[Rimrock]

Those original servoes are known to break donwn pretty quickly in this machine, so it's a quite common task to throw them out.
The 4'th valve have 2 positions, open and closed. It is supposed to be fully open when the 3 other valves are not moving, letting the oil circulate nearly without resistance through the valve block and to the tank. If manually putting the 4'th valve to closed position, and the 3 other valves in closed/center position on will hear the pump work harder as it now needs to circulate the oil to the tank via the pressure relief valve, which is set to a certain pressure in order to open. It can happen that the relief valve pressure setting is too low, and/or have a internal leakage. In this case the pump will not work any particular harder when pushing oil through it. The 4'th valve is set up with a mix on the radio towards the 3 other valves. When any of those 3 valves are moved, the 4'th valve will close.
I guess you most likely have an issue with center positioning of valves after replacement of the servoes, so would continue looking closer into that. I'm not so familiar with the Hitec vs Tower servoes, I clould not quite understand why it was needed to reverse the direction when changeing servo brand. It's new to me that some servoes runs in the oposite direction from others. But maybe that is correct. It should be easy to see when testing.

[gmmiller06]

Thanks everyone for the help! You guys steered me in the right direction. This thing has been sitting on my shelf for 5 years now because I was too intimidated to tear into her. In the last few weeks I got brave(and actually had a minute to work on it). I tore it down and checked everything. Now I don't remember messing with the pressure relief valve before but obviously I had. I was able to determine that I was an idiot back then and put this thing back together incorrectly. I fixed that today and she is up and running again. I may even get brave enough to change out my tx since I know more about mixing now.


TLDR: I'm an idiot and had put the pressure relief valve back together incorrectly at some point. She is running again now!