Morning all, looking at the drawings of this machine it looks like it is called the safety valve. There is pretty much no info I have been able to find. Whenever I type something in I get a main pressure relief valve which is not the same thing from my understanding. I am curious what this valve is for. I removed it trying to see if that is where my internal leak within the valve control body was and I found an o-ring had damage to it. I replaced this valve until I can find that particular piece but after re-installing my boom now slowly lowers with/without the engine being on. I am curious to know if I maybe damaged the o-ring further when I removed this. Does anyone know what this valve is for? Can it be adjusted? There is an allen set screw under the i believe 19mm cap.
That sure looks like your main pressure relief valve. Yes it is adjustable. Sounds like you may have sent some contamination down stream and caused a problem with your boom function valve.
I appreciate the response but looking at the cut away for this valve (E-E) it shows the main relief valve and the safety valve as two different items ... I am sure they work in tandem somehow.
The safety valve in this application is the same as a circuit relief valve. It is plumbed into all the cylinders and provides pressure relief should a sudden outside load be placed on the circuit when any particular control valve spool is in neutral. It is odd because most machines have a separate circuit relief cartridge placed in every circuit on a cylinder. The main relief valve protects the pump when a control valve spool is not in neutral.
Thank you for this. Next question ... looking at this parts diagram it appears to be a separate part which is fine. But when looking for that part the only thing that comes up is the relief valve assembly which does not include this component that has the failed o-ring. Another question ... if this valve is not working properly would it create the hissing/blow by sound in the control valve block itself?
If that valve were leaking through, then all the cylinders would be leaking according to the schematic that I have. The O rings can usually be matched up by a dealer. The cartridges are generally sold as one piece. The top number in the string of numbers is generally the number of the cartridge. You might try calling a dealer parts guy and asking what they can find out for you. If only the boom is drifting, I would look for components that only deal with the boom. It could just be a leaking packing in the boom cylinder.
Thank you for your insight. I would also mention that it appears that the boom is the only one drifting however that could be just cause its the most noticeable. It also does not hold pressure once the engine is off ... you can hear hydro returning back to the tank. When I first purchased the machine it did do this but it took a MUCH longer time .. sense I removed the safety valve to check it has gotten worse I do not think I adjusted the pressure but the manual does state the following ... "The pressure of the central safety valve cannot be set when it is mounted on the machine, so do not disassemble it." however it goes in later and says that you have to remove it to perform certain maintenance functions. Wish I would have read that part before I touched it ... prob would have left it alone lol. I wonder if I did accidently mess with the adjustment and that has created my new problem.
Unless you disassembled the cartridge, it isn't likely that you could have changed the setting. The pressure setting is the highest of all the safety valves on the machine.