So I am new to the forum but I like what I see so far. I am a relatively new to excavators (particularly Komatsu excavators) and I am hoping that I could get some information about the Self Pressure Reducing Valve. My questions specifically pertain to the Komatsu PC 240LC-11. Is the Self Pressure Reducing Valve specific to certain models? What is the role of the Self Pressure Reducing Valve in the system? What symptoms will an operator experience is the Self Pressure reducing valve fails? Are there any schematics or service information that might help me diagnose a failed Self Pressure Reducing Valve? Any help is greatly appreciated. Thanks! - Komatsu "IKE"
If you have a doubt about the PRV all you have to do is out a guage and test it
They are on all from -7 and up, all are slightly different. Will usually start with hyd going slow. The prv takes some of the pump oil and drops it down to around 35kgcm and is used rather than a separate pilot pump.
It's basically pilot pressure to run the pilot control systems, joy sticks, solenoid valves and some of the main pump functions. Plug a gauge into the pilot system and you can see what is there. This is usually a steady pressure but may drop a little when the engine is at low idle. There will be a minimum pressure spec in the book. It is kind of funny about the acronym being use "prv". On Cat systems the PRV is a control solenoid for the pump control and not something that controls pilot pressure through out the machine.
I really appreciate all of the info. You guys are great. Thanks!
John C., what I mean by PRV is: Pressure Reducing valve, as you have mentioned it is pilot pressure We all know that cat prv is the power control which is equivalent to PC-EPC or TVC on Komatsu
I was supplying info for those that might confuse the terms is all. I know you guys that turn wrenches for a living have a handle on those things